Driveshaft length

[frd2]

Drive shaft - dust boot interference.JPG

Need help with driveshaft length

Coyote TKO 600 2015 IRS

driveshaft is from factory five, part number is correct and length of shaft matches part number length.

It is so long it completely compresses the transmission dust boot / seal.

Anyone else experience this? F5 says it is fine but others say no way.

FYI - factory five has lengthened the drive shaft for this application on purpose to get more spline engagement so different part number and different length than the original ones (Like the 25th anniversary vintage..... )

Thanks for help
Greg

[Mountain-Metalworks]

At a core technical level, that "should" be fine. With IRS there are no moving parts in the suspension that affect the slip joint, it's going to stay in a fixed place the whole time. So you don't have to worry about the slip yoke getting slammed into the tranny during a big bump. That being said, your seal is going to get shredded pretty quickly and there is simply no reason to have that much spline engagement between the tranny output and the driveshaft slip-yoke. To me, it's about 1/2" to 3/4" too long.

If FFR says it's OK they probably won't do anything for you, so the worst thing you can do is run it like it is and see if the seal miraculously holds up. If it doesn't you have a case with FFR to provide a shorter one. I just can't see why they'd think it needs that much spline engagement.

-TJ

[frd2]

I was hoping to hear from another recent coyote IRS car w the same fitment issue to confirm mine is not a one off problem.

[edwardb]

I was hoping to hear from another recent coyote IRS car w the same fitment issue to confirm mine is not a one off problem.

The style slip joint you're concerned about has been in use for quite a few years with multiple suspension setups. Part of the slip joint showing is 100% normal, as in the picture below. In this position, there is plenty of engagement to the transmission output shaft. Solid axle builds typically need even more slip joint showing in order to handle the movement of the diff. And they're plenty strong as well. Crushing the boot on the back of the TKO is not normal and there's no reason for it. The only thing different about the 2015 IRS setup is the connection at the diff. Also posted on the other forum.

[wirelessnut]

That looks about the same ase the shaft FFR sent with my kit.20170804_145237 (1).jpg

Since I've changed to a T56 is way too long. Funny.

[wareaglescott]

Mine with the coyote, tko600, irs sits just as EdwardB shows in his picture.

You mentioned that FFR lengthened the drive shaft for this application. Do you know when this occurred?
I received my kit in June 2016 but they sent me the wrong driveshaft initially which I did not discover until I went to put it in about September 2016. I received the proper driveshaft at that time.
Did the change come after that? If not it seems yours should fit like mine and EdwardBs unless something else is off.

[frd2]

That looks about the same ase the shaft FFR sent with my kit.20170804_145237 (1).jpg

Since I've changed to a T56 is way too long. Funny.

Hmmmm. I will take mine out for a better photo of length but yours looks different. Mine is 3 1/2 " from rear flange to rear weld. Yours is a different rear flange and is only 3". Mine looks to be near the same length as yours overall, but I remember a number quoted from factory five of just over 11". Mine may be an optical illusion due to angle as I was trying to show the boot being smashed more than over all length. I will check tonight.

I may want to trade you...........

[frd2]

Mine with the coyote, tko600, irs sits just as EdwardB shows in his picture.

You mentioned that FFR lengthened the drive shaft for this application. Do you know when this occurred?
I received my kit in June 2016 but they sent me the wrong driveshaft initially which I did not discover until I went to put it in about September 2016. I received the proper driveshaft at that time.
Did the change come after that? If not it seems yours should fit like mine and EdwardBs unless something else is off.

I only made indirect reference to Paul's (25th anniversary time frame) which they said was different than mine. Not sure when since then they changed.

[jcrumpley]

Greg,

I wouldn't run it that way. That seal is one piece. It is a dust seal and oil seal all in one.

[edwardb]

I only made indirect reference to Paul's (25th anniversary time frame) which they said was different than mine. Not sure when since then they changed.

For the record, my Roadster build is a 20th anniversary model. The 25th anniversary Roadsters are a couple years away still.

If the change was to make it go from what mine looks like (as pictured) to what yours looks like (with the crushed boot) then it wasn't a good change. Enough said from my side.

[frd2]

Lol. Didn't mean to take 5 yrs off your life! Thanks for your comments and input.
Greg

[frd2]

That looks about the same ase the shaft FFR sent with my kit.20170804_145237 (1).jpg

Since I've changed to a T56 is way too long. Funny.

Here are photos of mine showing the difference in length. Longer with apparently different rear flange as well.....

driveshaft length.JPGdriveshaft.JPG

[edwardb]

Sorry, one more comment even though I said I was done... Analysis paralysis going on here. The measured length of the driveshaft is a bit academic at this point. What's important is how it fits in your chassis with the engine/trans and rear suspension mounted. IMO, yours doesn't fit. It shouldn't crush the dust cover/seal on the back of your TKO and some of the slip joint showing is completely normal. A number of people on both forums have said that. You can also find the same thing on multiple other forums, commercial websites, etc. Google it. I've had two custom driveshafts made by Denny's Driveshafts, a highly regarded and reputable shop. They have a worksheet where you measure everything in the assembled chassis, then they translate that into a proper fitting driveshaft. Both times the final product looked like what I pictured previously with a small portion of the slip joint showing. I can't explain why FF chose to change the length of the driveshaft for your configuration. Or why they say it's OK to install with the back of the TKO pushed like that. But it's not standard practice and running it like that is going to tear things up. If it's really only a dust seal, then maybe it doesn't matter. But not a choice I would make. I'm a firm believe in trusting the experts in the design and intended use of their parts.

[jcrumpley]

It is a one piece oil seal and dust cover. Here is a photo.617H5+DUYGL__SL1125_.jpg