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Thread: Limited slip installation instructions with pics

  1. #1
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    Limited slip installation instructions with pics

    The factory service manual is wrong and misleading in a few key places, and since I couldn't find a good thread here or on NASIOC that covered it all, I'm going to create one here.

    This covers installing a limited slip diff in the transaxle. It doesn't cover changing out the ring and pinion. In this tutorial, I used a 2007 WRX donor transmission. Instructions should be the same for any kind of LSD but I used a Quaife.

    Tools needed (beyond the typical torque wrench, sockets, combination wrenches, etc):
    - Dial gauge (not the push kind, but the lever kind like this
    - Shop press (not required but helpful)
    - T70 Torx bit
    - Wood shims (like from Home-Depot for installing doors and windows - not required but helpful)
    - Brass hammer (plastic hammer might work too)

    Parts suggested:
    - New o-rings for differential bearing carriers (2 total)
    - Input shaft seal
    - Driveshaft seals (2 total)
    - Differential carrier bearings (2 total)

    Remove the drain plug with the Torx bit

    With the transmission out of the vehicle, remove the engine mount and rear cover plate (if not already removed).

    Remove the two sensors that screw into the left side of the center differential housing (they have electrical connectors on them).

    Unbolt and remove the center differential housing. You will have to wiggle the gear selector a little bit to get it out. The center diff housing is the rear-most part of the transmission as seen in this pic:


    Remove this thrust plate which is just sitting behind the driven gear shown in the picture (the center diff case housing which you just removed helps keep it located):


    Next remove the four bolts that hold the pinion shaft in. You can see three of the four bolts in this pic:
    Last edited by Hindsight; 03-09-2015 at 05:22 PM.

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  3. #2
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    Next lay the transmission on it's RIGHT side (passenger side) and remove all the nuts holding the case halves together. All but a few of the nuts should be facing up. The only ones that aren't are the ones that can't be because the dipstick tube is in the way.

    Flip the transmission over on it's LEFT side and remove all the bolts you took the nuts off of. Do this carefully so the case halves don't split (just yet). Put a couple of 4x4s or stacked 2x4's under the transmission for support. You will need to be able access parts under the transmission and this will provide clearance. Also, the transmission can be very wobbly no matter what you rest it on so have some wood shims around to wedge in key places to keep it stable). Remove any remaining nuts and bolts facing upward. IMPORTANT: You are only removing nuts and bolts that go all the way through the transmission. There are a few bolt-looking things that hold the synchro selectors in place so don't remove those.

    Now, with the transmission on the 2x4s on it's left side, remove the upper (right) side case half by lifting it up and off. It will be glued in place with sealant so you may have to tap it in key locations using a brass hammer. It also tends to get stuck on the guide pins. You should now see this:




    Remove the driven shaft (that's the top shaft in the above pic) by grabbing it on each and and wiggling around until it lifts up and out. It should now look like this:


    Now remove the pinion shaft. It may require more wiggling and maybe some prying at the gear end but be careful when prying not to gouge any aluminum. Once the pinion shaft is out, the differential lifts right up and out:



    Remove the ring gear from the differential. I used an impact gun. The ring gear came right off:

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    Now put the ring gear on your limited slip. If it's too tight (like mine was), you can heat the ring gear in an oven at about 200, and put the diff in a freezer for 20-30 minutes. Tighten the differential ring gear bolts to 45.6 ft lbs.

    Now you can either re-use your old differential carrier bearings and races or get new ones. New ones are ~$80 each from the dealer and I feel is a good idea to replace them while you are in there. The bearings come with races as a matched set so make SURE you keep track of which race goes with which bearing. If you re-use your old bearings, I have heard you can sometimes finesse them off with a screw driver and some other tools, but be careful. If you suspect you may have damaged them in trying to remove them, don't re-use. To install new ones, just press them on with a shop press. I have heard they may go on by hand with the heat/freeze trick as mentioned above but I didn't try. The old bearing races are not pressed into the side retainers (the splined units on each side of the transmission); they will basically just pull right out. Pull them out and put the new ones in. If you are having trouble, simply remove the side retainers by unscrewing them (first remove the bolt holding their locking tab in place).

    Remove the side retainers by removing the bolt and the locking tab, then unscrewing them counter clockwise until they are out. I made this tool to help turn the retainers:



    With the side retainers removed, remove and replace the LEFT side retainer o-ring, and simply remove the right retainer o-ring (don't replace it just yet). The reason for this is that the o-ring causes friction and makes it difficult to adjust the bearing tension later.

    Put the new races in (or old ones if you are re-using them - ensuring you put the same side back in the same side) and screw the LEFT side retain in just a bit. Maybe 1 full turn after it starts to thread.

    Install the new input shaft seal by sliding the old one off and the new one on.

    Drop the new differential in, then the pinion shaft, and then the driven shaft. A couple of things about this. There are some shims on the back side of the pinion (where you removed the four bolts early on in the procedure). Be careful not to damage these! These set the height of the pinion and since you are not changing the ring and pinion, you don't need to mess with these. Also note that there is one pinion and one driven shaft bearing that have a hole in them to accept a nub in the case half. It will take some fiddling to get these all lined up properly so both shafts drop in all the way and the gears mesh all the way.

    In this shot you can see the nubs I'm talking about for the bearings (circled in red):


    Another thing to note: The plate that holds the pinion in (with the four bolts and the shims behind it) can sometimes rotate on you during the job. The holes are drilled such that the shims and the plate can ONLY go on one way. If you are having trouble getting things to fit back in, rotate the shims and plate until their holes line up with the left-side case holes. Lastly, there is a circlip on the driven shaft that can get caught in the wrong place. In the pic below, the circlip is interfering with the pinion shims and plate. Rotate the circlip around so the open area of it is facing the shims and plate and allowing them to have clearance (in the picture below, it shows the WRONG orientation for the circlip - note how the opening is in the wrong place and the lower part of the circlip is coming into contact with the shim.... you would rotate the circlip so the opening moves down so it clears the shim):
    Last edited by Hindsight; 01-11-2015 at 07:46 AM.

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  7. #4
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    Now you should be back to this:


    Clean off all the old gasket material and wipe the case halves with acetone, then apply a thin bead of your favorite transmission oil proof sealant (I used Hondabond). Next place the right case half back on top and tap it down into place with your first. When doing this, be very careful of those pinion shims.

    Once the case is in place, put the bolts in. With the case on it's left side still, all the bolts go in from the top down (nuts on the bottom), with the exception of the ones that can't due to obstructions.

    You should torque the nuts, not the bolts, and that will require you to flip the case over to the other side but before you do, thread the right side adjuster in about 5 or 6 turns (just to help support the diff and keep it from rattling around too much)

    Torque specs and sequence are shown in the pic below from the factory service manual. Be sure to do them in order. Note the larger bolts are the ones with a star next to them and get torqued first, and tighter. Torque the case halves first and then the pinion plate with the four bolts.



    With everything torqued and triple checked, flip the case back over onto the left side. Remove the top side adjuster. Now, while turning the input shaft with one hand, turn the left side adjuster in (tightening it) and keep tightening until you feel the side adjuster become difficult to tighten. What you are doing is moving the ring gear upwards, closer to the pinion. When it gets difficult to turn, it means the pinion has bottomed out on the ring gear and you are at zero backlash. Here is a side view of what it looks like. Turning the left side adjuster in moves the ring gear closer to the pinion (first picture below) and loosening it moves it further away (second pic below):


    So now, if you install the right side adjuster, nothing you do to it is going to cause the ring gear to move or change the backlash since that's now set with the left side adjuster. At this point, all the right side adjuster can do is set the bearing preload which is the tension pressing in on the bearings.

    Now that you are at zero backlash, it's time to take any slop out of the bearing races which may not be 100% seated (no real amount of pressure has been placed on them yet). To do this, thread the right side adjuster in place and tighten it until you feel resistance (this means it's just started to pinch the bearing race against the bearing), then tighten it again until it becomes very difficult to turn by hand (about 1-3 teeth). You can tap the case around the adjuster with a plastic hammer to help (per the FSM). Now back off the right side adjuster a couple of turns to get it away from the bearing so it isn't interfering with anything.

    Now that any slop is gone, back off the left side adjuster a turn or two, then repeat the procedure with the left side adjuster to get back to zero backlash (slowly tighten it while you turn the input shaft until you feel resistance).

    Subaru says to run the diff at .0051 to .0071 backlash. The teeth of the ring and pinion are tapered in a "V" shape so moving the ring gear away from the pinion creates backlash or free space between the gears. To get to the ballpark, back the left side adjuster off (loosen it) by 3 teeth (teeth of the side adjuster). You can mark the side retainer or case with a sharpie to help. Subaru says that for every tooth you turn the side adjuster, the backlash changes by .0021 so 3 teeth would equal .0021 x 3 = .0063 which is in spec. The reason you can't just do this and call it done is that your starting point of 0 backlash is never going to be truly 0 backlash. When tightening the left adjuster and stopping when it gets "hard to turn", there is a course of about 1-2 full teeth where you could interpret it as "hard to turn". When do I stop?! You don't really know so you just feel it with your best guess, back it off three teeth from there, and then start checking with the dial indicator.

    So now that the backlash is set to ballpark, screw in the top side retainer until resistance is felt (which would be 0 preload), then tighten a further 1 tooth to set the proper amount of preload on the bearings. There is no measure for pre-load. Oddly, the 5 speed instructions say to use 1 tooth while the 6 speed says to use 2 teeth, and both 5 and 6 speed side retainers move in and out the same amount for each tooth of adjustment. I stuck to 1 tooth.

    Now, to check the backlash accurately, you need to lock the pinion shaft TIGHT. A wrench and socket won't work... too much free play. I tried that and even though I was VERY gentle while checking the backlash and could swear the pinion shaft wasn't moving at all, my readings were larger than when I locked the pinion shaft tight using this method: Put a pair of vise grips on the pinion shaft nut, then rest them against something very firm and stable and put a weight on top of the end of the vise grips like this:


    Now put one of your drive shaft stubs in the right side of the transaxle. Now mount your dial indicator and put it on the face of a tooth as far out as possible (meaning, as far toward the outside of the ring gear as possible). I made a mount of steel bar stock I had and it looks like this all setup:



    Put the transmission in 4th or 5th gear by moving one of the selectors. It isn't critical that it's 4th or 5th (but higher gears multiply torque less which gives less of a chance of the pinion shaft moving and throwing off your numbers). The shift forks are circled here. You can see three of them. Push in or pull out on one of them to engage a given gear. The middle of the three is 3rd and 4th gear but I forget if in is 3rd or out is 3rd. You can check yourself by trying both, then rotating the input shaft and seeing which gear makes the driveshaft stub rotate faster (that would be 4th).




    Now move the driveshaft stub clockwise until it stops, note the reading on your dial indicator, then rotate it counterclockwise and note the reading. You want .0051 to .0071 total. The FSM tells you to adjust the RIGHT side adjuster to make any adjustments to the backlash at this point but that's wrong! If you just spin the right side adjuster, you'll only increase or decrease the preload on the bearings. If the backlash is too much, it means the ring gear is too far away from the pinion. If the backlash is too little, it means the ring gear is too close to the pinion. Adjust it by first loosening the right side adjuster a turn or so (to take the load off the bearing and allow you to more easily move the left adjuster), then TIGHTEN the left adjuster to DECREASE backlash or LOOSEN to INCREASE backlash. I start by moving them 1 tooth at a time. After your do this, tighten the right side adjuster until you feel resistance, then tighten one more full tooth to set the bearing pre-load as before. Now re-check your play. Repeat until you have the correct amount of play. Once you are there, you have finished setting backlash and preload.

    Now install the right side adjuster o-ring by first marking the tooth against the case with a sharpie to mark your position (which is the proper preload), then loosening it until you can see the o-ring groove, install the new o-ring, then tighten the adjuster until your mark lines up. The point in not putting the o-ring in until last is that it made it easier to feel the resistance for bearing contact and pre-load that you were previously setting.

    Install the locking tabs to keep the side adjusters in place. If the tabs don't fit, flip them over. You can now install new driveshaft seals if you want now too.

    Some people check the ring and pinion contact pattern. I did this initially but realized that you don't have to if all you are doing is swapping the diff; the pinion height won't change and the backlash is set with the dial indicator.

    Lastly, clean up the gasket material for the center diff housing mating surfaces with a razor blade and acetone. You can either get a new paper gasket or just use more liquid gasket maker like Hondabond (don't use both though). Replace the big thrust washer removed earlier in the procedure (don't forget to do this as it's easy to forget). Put the gear selector in place on the shift forks and slide the housing in place and bolt on. Don't force the housing if something feels like it's blocking it. On mine, I had to go in with a screwdriver and gently nudge the big thrust washer a bit left and right to get it to be in whatever perfect orientation the case wanted it. Torque the housing bolts to 18 ft lbs.

    Put the drain plug back in and torque to 32 ft lbs if you have an aluminum crush washer or 51 ft lbs for a copper crush washer.

    Hope this helps.
    Last edited by Hindsight; 01-11-2015 at 07:37 PM.

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    Senior Member Canadian818's Avatar
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    Wow! Thanks for putting in the work, lots of detail. I Just might try this myself now.
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    Member Ellimist's Avatar
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    Second that - this is awesome! Personally still wondering about some aspects of the backlash, but I'm not sure I can ask a coherent enough question yet that won't waste others time, LOL. In any case, this plus a little more reading and I'm feeling good about doing this myself!... Gonna start saving for the Quaife right away!

  12. #7
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    Thanks guys. I updated to include the torx bit size and all tightening torques.

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    Senior Member Tamra's Avatar
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    Great write up!
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    Senior Member JAubin's Avatar
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    Awesome write up! I'm getting ready to do this soon and it will definitely come in handy.

    Some P/Ns if you choose to replace these (for an '02 in my case):
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    Axle Seal (Left) : 806730042
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    Sticky worthy for sure...many thanks!
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    Nice job!!!
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    Senior Member Silvertop's Avatar
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    A VERY nice job! Still not sure if I will attempt it myself -- I've always found transmissions a little scary -- but maybe...........!

    What I'd love to see is a photo sequence displaying the half-shaft conversion necessary to convert a 5MT for use with a Quaife QDH3Y.

  18. #13
    Harley818's Avatar
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    nice work Hindsight.
    I'm waiting to drive it first, then determine what type of LSD I want.
    Now I feel a little more confident with your instructions and pics to attempt it myself.

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    Thanks for the step by step. One thing I want to add is Remove the steel throw out bearing sleeve. It took me a minute to figure out what was keeping the case together. On my 04 transmission it has 2 set screws that are 180* from each other along with some Locktight. It did take a little effort to get is started with a small slide hammer but once it got moving it came right off.

    IMG_1637.JPG
    Last edited by Mitch Wright; 03-09-2015 at 05:05 PM.

  20. #15
    Senior Member Mulry's Avatar
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    First off, this is a great thread. Thanks for documenting all of this Hindsight. It was super-helpful in getting our LSD installed this weekend.

    I have a couple of additions, I'll include them with the photos. I can send you the larger sized ones if you want to incorporate these into the thread itself.

    Post 3 describes the "nubs" or dowels that locate the bearings on both the driven gear shafts and the pinion gear shafts. Locating the bearings on those nubs can be difficult, since the nubs are blind when you're putting in the shafts. Here's how I solved that problem:

    Before putting the new differential in, mark the location of the nubs on the case with a Sharpie, like this:

    IMG_1838.JPG

    Make a similar mark on the bearing on the pinion shaft and on the bearing on the driven shaft. Here's what it looks like on the pinion shaft bearing:

    IMG_1839.JPG

    With the differential still out of the case, lay the pinion shaft in the case and rotate the bearing until the nub slots into the divot in the bearing so that you know that the bearing is in the same position in which it will need to be when you do the final assembly.

    Unfortunately, when the LSD is in the case, you won't be able to see these marks very easily on the pinion shaft bearing, so we need to mark the face of the bearing someplace where we can easily see it during installation (this isn't a problem on the driven shaft bearing because the LSD isn't in the way on that one). You can use the case location where it intersects the bearing as your reference mark, since you can (a) see that easily and (b) it's not going to move when you install the pinion shaft. With the pinion shaft still in the case, from the step above, mark that location with your Sharpie:

    IMG_1840.JPG

    I got Sharpie on both the case and the bearing, so when I removed the pinion shaft to place the LSD in the case, I wiped the Sharpie off the case with a little acetone in order to make it easier to see the line on the bearing during installation.

    Next, put the LSD in the case and install the pinion shaft. You should be able to freely rotate the bearing. If you marked it as I did above (and erased the extra Sharpie marking that got on the case), then it will look like this when it's rotated into place correctly:

    IMG_1841.JPG

    Since there is some axial play in that bearing (by design), you can slide it along the shaft until the nub fits into its slot (phrasing!) on the bearing, but with this marking, you'll know that the bearing is in the correct rotated location and all you need to do is slide the bearing to engage the nub.

    Cheers guys.
    Last edited by Mulry; 11-09-2015 at 12:52 PM.

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    This should be a Sticky!
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    WOW this is amazing. Wish I had this last year when taking transmissions apart. Great write up, +1 for sticky!

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    Senior Member Mulry's Avatar
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    Who do we need to talk to about getting this stickied? It was a tremendously helpful post for me to do our LSD install and I never would have found it with the forum search tools but Hindsight thankfully mentioned it in another thread for me.

  24. #19
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    I'll shoot the admin a message and see if he'll do it.

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    Done! I agree, great write up.


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    Great! Thanks Dave for the sticky and thanks Hindsight for the write up. Now get us one for rebuilding an engine!

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    Great write up
    For those putting in an OBX or other early style LSD into a later model gearbox, the diff output shafts change from female to male, and the seals need to be changed
    image.jpg
    RHS seal suits female, LHS seal suits male output


    image.jpg
    Part numbers for seals, the left and right seals are different part numbers

    image.jpgimage.jpg
    Adjustment tool needs to clear the output shaft

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    Hi all. I just went through this procedure to install a cusco lsd. These instructions are invaluable. I reassembled everything and set the backlash, but something seems to be binding when I turn the axle shaft. The transmission is dry, so not sure if this is due to a lack of lubrication or there is some other problem. I've gone through the backlash procedure twice and still feel it. I can turn the axle shaft, but it seems to "stick" in places and is not a smooth spin.

    Nothing in the transmission looked out of the ordinary. There is one shim on the rear pinion shaft that is back in place. The case went back together without any issues so I think everything inside was seated correctly.

    I assume this is not normal, so any suggestions as to what this might be before I split the case again? It is an 03 WRX trans and I installed the cusco type RS lsd.

    Thanks

    Skip

  29. #24
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    Glad the instructions helped you. The binding is not normal and should not happen. Lack of lubrication won't cause it. does it happen regardless of which gear you move the selectors into? IE does it happen when it's in gear as well as when it's in neutral? If it happens in neutral, then it sounds like there is binding at the ring gear. If there is binding only when it is in gear, then it sounds like there is binding between the input shaft and the drive shaft (binding between 1st-5th gears).

    I'm guessing it is binding in neutral and also when in gear which would point to a ring and pinion issue. What could cause that would be if the ring gear didn't get perfectly seated on the limited slip housing.... IE it isn't laying on it's seat perfectly flat. How tight was the fit of the ring gear on the Cusco? Was it REAL tight? Did you have to freeze the LSD and heat the ring gear to get it on or did it just drop right on? If it didn't just drop right on, there is a chance it isn't sitting on there level. Or maybe you got a piece of dirt or something caught between the ring gear and the diff housing preventing it from laying perfectly flat? To test this, check your backlash at several different points of rotation on the ring gear. I check it where there is no binding, then turn the input shaft with the transmission in gear until there is binding, then check the backlash. If your backlash goes away where it binds, that really suggests the ring gear is not sitting flat.

    The other thing could be that the differential carrier bearing races are not sitting level. Did you remove the races? They ride in the removable threaded carrier housings (which is what you tighten and loosen to set the backlash and the preload). In one of the steps above, you are supposed to tighten both of them very tight while tapping on the outside of the case with a platic hammer to try to "set" those races and ensure they are flat. I think this is a long-shot though.... my money is on the ring gear not being level - whether that is due to a problem during the installation (you didn't get it perfectly flat or something is wedged under it), or the Cusco just isn't properly machined flat (fairly unlikely).

  30. #25
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    Hindsight, thanks for the quick reply. The binding happens in neutral. When I checked the second time, backlash in a non-binding spot was about 6 thousands. backlash in a binding spot was about 1 thousands. The ring gear slipped on without any problem. No heating required.

    Also, the bearing races basically fell out when I removed the threaded carriers, so there doesn't seem to be any binding in the races.

    I will first pull out the threaded carriers and races and go through that tightening procedure again since thats the easiest to do. I didn't tap on the case with a hammer when tightening the races. Maybe one of them is not just right and there is a little wiggle somewhere.

    Thanks again.

    Skip

  31. #26
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    If it comes to pulling the diff out, I would check the total thickness of the ring gear + diff housing using micrometer calipers at several points around the circle (12:00, 2:00, etc). Should be exactly the same all the way around. Unless you dropped your pinion shaft, I don't think there is anything there that could cause this. I would focus on the ring gear and the components attached to it.

  32. #27
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    Just to follow this up and to maybe save someone else from doing something stupid...
    I opened up the trans and found the problem. After I installed the LSD, closed everything up, set the backlash, I started to reinstall the end section. In doing this I removed all of the center diff parts that will not be used, including the parts on the end of the pinion shaft. I don't have my kit yet, so I didn't install the pinion shaft coupler, and just loosely put the nut back on the shaft. I didn't realize the purpose of this nut was to keep the inner shaft tight with the outer shaft. So, without the coupler the inner pinion shaft was free to slide in and out as it pleased. When I turned the diff shafts forward, the pinion would climb the ring gear and bind. When I turned it in reverse, it would back down the ring gear.

    I put it all back together with the pinion shaft parts and everything is working as it should be.

    Thanks again for you help hindsight.

    Skip

  33. #28
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    No problem - I'm glad you got it figured out so quickly and nothing expensive happened.

  34. #29
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    THIS is exactly what I needed! Now, did you use or recommend blue loctite on the ring bolts, because I used blue loctite.

  35. #30
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    I did not. I tried using it on another diff I put together on a Jeep and some of the loctite oozed out between the differential body and the ring gear. As loctite dries, it expands. It expanded enough that, despite the torque on the bolts, it impacted the backlash; the backlash was different on multiple positions of the ring gear. The factory doesnt put loctite on the bolts either so my rule is to leave it off. If I get a diff kit and it comes with pre-applied, dried thread compound on the bolts, I WILL use them, but I will not add loctite. These are my opinions and I am by no means a expert.

  36. #31
    Senior Member Bob_n_Cincy's Avatar
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    Quote Originally Posted by Hindsight View Post
    I did not. I tried using it on another diff I put together on a Jeep and some of the loctite oozed out between the differential body and the ring gear. As loctite dries, it expands. It expanded enough that, despite the torque on the bolts, it impacted the backlash; the backlash was different on multiple positions of the ring gear. The factory doesnt put loctite on the bolts either so my rule is to leave it off. If I get a diff kit and it comes with pre-applied, dried thread compound on the bolts, I WILL use them, but I will not add loctite. These are my opinions and I am by no means a expert.
    Hindsight.
    I'm sure not an expert when it comes to the MT5 transmission. About a year ago, my 818 with 2006 MT5 with about 400 autocross launches had all the ring gear bolts come loose and punch holes in the case. I have no reason to believe this transmission was ever previously apart.
    See my very poor video:


    Bob
    Last edited by Bob_n_Cincy; 01-30-2017 at 01:58 PM.
    818S #22 Candy Blue Frame, Front Gas Tank, 2.5L Turbo, Rear radiator, Shortened Transmission, Wookiee Compatible, Console mounted MR2 Shifter, Custom ECU panel, AWIC soon
    My Son Michael's Turbo ICE Build X22 http://thefactoryfiveforum.com/showt...rts-818S-Build
    My Electric Supercar Build X21 (on hold until winter) http://thefactoryfiveforum.com/showt...e-Build-Thread

  37. #32
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    I remember that... scary stuff Bob. I haven't heard of that happening commonly though.... at least I haven't seen reports on NASIOC about it or anything. I don't THINK the service manual calls for any thread compound.

  38. #33
    Senior Member fastzrex's Avatar
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    Joe, thanks for the list of seal and bearings for this install.
    ~ Mark

    818C S/N 429ES: Start Date 1 September 2016
    2001 NB Miata LS3 V8 440 rwhp
    2004 Miata MazdaSpeed Factory Turbo

  39. #34
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    Anyone happen to know the difference between the 806340030 and 806340080 bearings?

    I'm converting a TY755VB1AA, JDM forester 4.44 male output shaft transmission, to a female transmission and doing an LSD upgrade while I am in there.

    I know I have to switch to the newer female tranny seals. But I haven't been able to find any info on the difference between the two styles of bearings. Both part numbers are listed on the parts diagram, which generally means one is just a newer part number and either is fine. But every once in a while Subaru will throw you a bit of a loop and there is some tiny change that requires one or the other.

    Thanks for the great write up and everyone be well.
    Last edited by ssssly; 06-26-2018 at 06:40 PM.

  40. #35
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    Very thorough write-up. Thanks for this.

    ss

  41. #36
    Senior Member Dave 53's Avatar
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    Been a while since any activity on this post. Seeking additional new advice before trying this.

    I track my car and I'm really feeling the open diff on the exit of a few tight second gear turns. An LSD is needed.

    The tranny in my car is a 5 speed with 10,000 miles since rebuild. Should I put the LSD in this tranny? No rebuild of any other parts since that was done 10,000 miles ago.

    I have a spare 5 speed. Or should I open up the spare, do a total rebuild while it's open (whatever that entails) and install the LSD in that tranny?

    I found what seems to be a reputable tranny shop that only works on manual trannies that said he would install the LSD for $500. Should I just pay it? I'm not terribly afraid to try, especially with this write up, but this is new territory for me. How long should this job take? Because if I end up spending 10 hours on it, I would rather just pay to have it done.

  42. #37
    Senior Member STiPWRD's Avatar
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    $500 to install the LSD is very reasonable, most shops in my area would charge double that. I would put the LSD in the spare 5-speed and do the bearings and seals while you're in there.

    Are you running at stock power levels and have you done the "leveling out" mod to lower the back end of the trans? In my experience, running increased power levels over stock and having the back of the trans tilted up (as it comes from FFR) can really reduce the lifetime of the 5-speed due to non-ideal oiling. They are not very strong but they are much much cheaper than the 6-speed. I'm on my 3rd and final 5-speed. When this one breaks, I'm getting a 6-speed.

  43. #38
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    I agree that $500 is very reasonable, but that's only if they do a good job. I know of one guy who had a shop replace his R&P and it blew up 10 miles later.

    I also agree that the 5 speed is not very durable on these cars and if I had it to do over again, I would have just gone with a 6 speed.

  44. #39
    Senior Member Dave 53's Avatar
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    265 whp, so not crazy power. Based on a Flatirons podcast about the 5 vs 6 speed, I'm well within the green zone for a 5 speed. I haven't lowered the rear of the tranny, but I raised the engine a bit to keep the Killer B oil pan from being the lowest point under the car. 10,000+ miles since total rebuild including 13 track days. Wish I had the cash for a 6 speed, but so far, the 5 speed ain't broken (and I've got a spare if it does).

    Because of the help of this forum, I'm gonna do this! Winter project.

  45. #40
    Senior Member Dave 53's Avatar
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    Trying to split the case halves and I literally think the place the rebuilt it used glue and not a gasket product.

    I tried heating the case seam up to 200* and it won't budge.

    Looking for tips on breaking the case apart.

    Note: It ended up being I missed the 2 "center" bolt. The ones not on the perimeter of the case.
    Last edited by Dave 53; 04-29-2023 at 10:52 AM.

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