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Thread: Control arm assembly question

  1. #1
    JohnK's Avatar
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    Control arm assembly question

    I'm continuing to work through the assembly of the front and rear control arms so I can get them all test fitted in the chassis prior to powder coat. For the front lower control arms, as well as the rear IRS upper and lower control arms, I'm using the new spherical bearing inserts that FFR now offers. They seem like a nice upgrade, even for a street-only car. They are, however, a little different to install than the poly bushings they replace. First off, in order to be able to get the outer bearing sleeves in, I have to sand away the powder coat on the inside of the bearing tubes pretty much down to bare metal. I could possibly get away with removing a bit less, but that would require pounding or pressing in the outer bearing sleeves, and that would be pretty much a "one-time in and it's done" deal vs. having the ability to remove and re-orient the bearings in the control arms. This is significant because the bearings are not symmetrical in terms of how much they protrude from the edge of the control arm. On the one side, the tapered inner sleeve is almost flush (maybe ~1/16 protrusion) with the outer sleeve. On the other side, the inner sleeve sticks out quite a bit more (~3/16?). As shown here:

    http://www.factoryfiveparts.com/sphe...-control-arms/

    In speaking with the folks at FFR, this is by design so that the suspension can be tuned by shifting around the control arms. Playing with how the bearings are installed, you can make the overall control arm fit wider or narrower, or shift the arm forward or backward. Given that my build is street-only, I'm not overly concerned with tuning the suspension, but this ability is very handy in being able to find the best fit for the control arms in the chassis with the minimum amount of frame tab bending.

    This is all a very long-winded way of saying that being able to remove and re-insert the outer bearing sleeves during fit-up is handy, but this requires the inner tube to be sanded down to bare metal. So when I do finally decide how I want all the bearings oriented, what's the best way to assemble everything so I don't end up with a bunch of corrosion where aluminum (bearing sleeve) meets bare steel (control arm). My original thought was to coat the bearing sleeves with anti-seize, but I was in the auto parts store today and saw a tube of something called Permatex High Temperature Sleeve Retainer. This sounds like the perfect solution, as it's designed to lock slip fit sleeves in place and provide corrosion resistance. Is this a good solution, or are there better options?

    Thanks,
    John
    MkIV Roadster build: Gen 2 Coyote, IRS, TKO600. Ordered 10/24/18. Delivered 1/29/19. Engine installed 8/8/21. First start 9/12/21. First go-kart 9/17/21. Off to paint 4/11/22. Back from paint 12/30/22. Build thread here.

  2. #2
    Senior Member CraigS's Avatar
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    Seems on the surface to be a good product. My concern would be how you would remove them later if needed. That amount of surface area, w/ a product that sounds similar to blue loctite, would be a real bear to disassemble. Do they say anything about removal?
    FFR MkII, 408W, Tremec TKO 500, 2015 IRS, DA QA1s, Forte front bar, APE hardtop.

  3. #3
    JohnK's Avatar
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    Yeah, that's a concern for sure. This is what they have to say about that:

    "To disassemble parts, weaken cured Sleeve Retainer by heating above 500°F (260°C); then use presses or pullers to separate components."

    So it seems that removal is possible, but would involve heating and pressing out the outer bearing sleeves.
    MkIV Roadster build: Gen 2 Coyote, IRS, TKO600. Ordered 10/24/18. Delivered 1/29/19. Engine installed 8/8/21. First start 9/12/21. First go-kart 9/17/21. Off to paint 4/11/22. Back from paint 12/30/22. Build thread here.

  4. #4
    Senior Member CraigS's Avatar
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    That works.
    FFR MkII, 408W, Tremec TKO 500, 2015 IRS, DA QA1s, Forte front bar, APE hardtop.

  5. #5
    Senior Member rich grsc's Avatar
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    DO NOT use the sleeve retaining compound. Did Factory Fave say to use a retaining compound.

  6. #6
    JohnK's Avatar
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    Quote Originally Posted by rich grsc View Post
    DO NOT use the sleeve retaining compound. Did Factory Fave say to use a retaining compound.
    Hey Rich. No, I haven't had a chance to call them yet and ask them. On my list of things to do on Monday. I'm curious as to why you say not to use the sleeve retaining compound? If I don't use that, what suggestion do you have on how to keep the bare steel control arm material from corroding? My other thoughts were grease or anti-seize, but both of those would facilitate the outer bearing sleeve spinning more freely, which is the opposite of what I want, no?

    Thanks,
    John
    MkIV Roadster build: Gen 2 Coyote, IRS, TKO600. Ordered 10/24/18. Delivered 1/29/19. Engine installed 8/8/21. First start 9/12/21. First go-kart 9/17/21. Off to paint 4/11/22. Back from paint 12/30/22. Build thread here.

  7. #7
    Senior Member rich grsc's Avatar
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    They are not going to spin, nothing spins at the arm, it has bearings inside that allow movement. You all ready found they are a tight fit, so I don't know why you think it would move after it was assembled. I would never want it put together in away that would prevent me from taking it apart in the future, and applying 500* of heat would destroy the powder coating. If you want to permanently fix them in place, thats your call, not necessary.

  8. #8
    JohnK's Avatar
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    They're going to pivot at the point of least resistance. Of course, they should pivot at the inner bearing, but why would I make it easier for them to pivot at the outer bearing by lubing that?
    MkIV Roadster build: Gen 2 Coyote, IRS, TKO600. Ordered 10/24/18. Delivered 1/29/19. Engine installed 8/8/21. First start 9/12/21. First go-kart 9/17/21. Off to paint 4/11/22. Back from paint 12/30/22. Build thread here.

  9. #9
    Senior Member rich grsc's Avatar
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    Don't know what to tell you John, you're overthinking it. The BEARING are almost friction free, so why would a pressed fitting turn? Just do what you think you should, you'll be happier.

  10. #10
    JohnK's Avatar
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    OK, so.....

    following the previous conversation, I called FFR and asked for their input. They agreed that bare aluminum against bare steel could result in galvanic corrosion, and that installing the bearings with some sort of coating was probably a good idea. They agreed that antisieze was a good solution, so I went ahead and prepped all the control arms (front lower and rear upper and lower) with antisieze on the outer bearing shells after I was finished test fitting everything.

    I finally got the chassis back from powdercoat late last week and I began assembling the front suspension. As soon as I torqued the front LCA bolts it was immediately obvious that I had a problem. Two of the four bearings were pivoting between the control arm and outer bearing shell. NOT the place where they're supposed to pivot. Another call to FFR, and they agreed that this wasn't ideal. They also agreed that the antisieze was the problem and that something that would positively retain the bearing shell and coat it was a good idea, so they suggested I go with the Permatex sleeve retainer mentioned above.

    Today I removed the LCA's and cleaned off all the antisieze (FUN!). I reading the instructions for the aforementioned sleeve retainer, it recommends cleaning the surface with Permatex surface prep. The instructions for that indicate that it cleans the surface and accelerates the curing process (which is normally 4 hours to set and 24 hours to cure). OK great, except, in my humble opinion I think Permatex could be a little more forthcoming in explaining that it accelerates the curing process from 4 hours to about 4 milliseconds. I coated the LCA and the bearing shell with a light coating of the sleeve retainer and went to twist it on. It got about half way and set up. SOLIDLY. There was an instant OH S&%$ moment, and I attempted to pound it back out with an extended socket and rubber mallet. This was literally about 10 seconds later. Nothing. NADA. It was locked in there. Mind you, this was with only half the bearing shell inserted and I could not pound it back out. It finally took heating up the bearing with a propane torch while simultaneously applying pressure with a bearing puller to get it out. Needless to say, it was destroyed when it finally came out.

    Luckily, the LCA seems OK. However, what's now obvious is that, had I been successful in completely inserting that bearing into the LCA, it would have been a permanent installation. Any bearing failure down the road would basically mean throwing the control arms away.

    So, here I am now. A new spherical bearing is on order, but I'm wondering what the best course of action is going forward. If I assume the following:

    - Something is needed to coat the bearing shell to prevent galvanic corrosion between it and the LCA.
    - Antisieze, or anything like it, is too slippery and will allow the LCA to pivot on the outer bearing shell.
    - The sleeve retaining compound is too strong and will result in, at worst, a repeat of this installation fiasco and at best a 'disposable' LCA if the bearing would ever fail.

    So I'm left wondering what to use that will provide a corrosion barrier and enough grip to prevent the bearing shell from spinning but could be released later if needed? Silicone adhesive? I'm honestly about ready to ****can these things and go back to poly bushings, but now that I've ground off the PC off the inside of the control arms the poly bushings would be a loose fit and I'd be right back here asking for suggestions on how to glue in poly bushings. Any and all suggestions are welcome at this point.

    Thanks,
    John
    MkIV Roadster build: Gen 2 Coyote, IRS, TKO600. Ordered 10/24/18. Delivered 1/29/19. Engine installed 8/8/21. First start 9/12/21. First go-kart 9/17/21. Off to paint 4/11/22. Back from paint 12/30/22. Build thread here.

  11. #11
    Senior Member CraigS's Avatar
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    Good old blue loctite? Or nearly any 2 part epoxy?
    FFR MkII, 408W, Tremec TKO 500, 2015 IRS, DA QA1s, Forte front bar, APE hardtop.

  12. #12
    JohnK's Avatar
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    Quote Originally Posted by CraigS View Post
    Good old blue loctite? Or nearly any 2 part epoxy?
    Blue Loctite probably would have worked.

    I wanted to post a quick note in case someone else stumbles across this thread in the future. After a bit more searching on suitable retaining compounds, it turns out that Permatex does not make anything that's lower-strength than what I tried, but Loctite does make a medium-strength retaining compound - Loctite 641. The description states:

    "LOCTITEŽ 641 is designed for the bonding of cylindrical fitting parts, particularly where disassembly is required for servicing operations."

    So I cleaned up the LCA's one more time, threw the bearings in the freezer for a few minutes (mostly to drop the temp a bit to further slow the cure rate), and they slid right in without a problem. I'm looking forward to putting this little hiccup behind me and moving forward.
    MkIV Roadster build: Gen 2 Coyote, IRS, TKO600. Ordered 10/24/18. Delivered 1/29/19. Engine installed 8/8/21. First start 9/12/21. First go-kart 9/17/21. Off to paint 4/11/22. Back from paint 12/30/22. Build thread here.

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