Rebuilding Front Lower Control Arms
 

I have the old bushings removed from my front lower control arms and new bushings from 928 Intl to install. For those of you who have done this, is any lube required for install or press them on dry? Does the front arm bushing get installed first then the bolting ring over it or do they get pressed on together at the same time?

Thanks

I useda little bit grey molykote grease on the edge of the holes to prevent the rubber to enter in the wrong angle.

Thanks for the feedback. I plan doing them tomorrow. I’m going install the front bushing in the collar and then mount it on the arm. Thanks

I looked in my barn what I use.
It's really hard work and buying in exchange is clever!
https://cimg2.ibsrv.net/gimg/rennlis...68fa9fe138.jpg
I think somethere Porsche recommend this
https://cimg3.ibsrv.net/gimg/rennlis...1a2a4c1471.jpg
You need a press
https://cimg4.ibsrv.net/gimg/rennlis...a7478f715f.jpg
And brute force, the steel inlet is a PITA

I'm not sure what bushings you have, but if they don't have a slight bevel on the outer edge it can make it tough to get them started....a huge press can break off a chunk of rubber (or poly) if part of the edge refuses to cooperate. If it's a square edge, you might run it against a grinder and create a small bevel all the way around. Also, I've done some replacements on other cars that seemed like they just wouldn't go in, so I used a sanding drum on my dremel to bevel the opening on the control arm and "polished" the inside of the hole...it made things work much better.

if you're using poly bushings, let me know what type of lube you used??? squeaks are the nemesis of poly and i'm trying to come up with a formula that works LONG TERM. i just replaced upper control arm bushings using different lubricants on both sides. on seems to work perfectly, but time will tell. the other squeaked after a couple days... the side that seems to be ok was basically silicone gel with a ton of graphite added. but i won't swear by it until it's been quiet for at least a year.

It seems to me that the purpose of a rubber bushing is to 'hold tight' onto both the inner and outer metal to which it is connected. Slippage on either negates the purpose of the bushing. Thus, mounting as DRY as possible should be the goal. Any lubricant used would hopefully be volatile and be gone over a short period of time.

This objective makes installing the inner metal piece difficult I know, but will result in better functioning when in service.

I thought the same thing..but..I'm not sure the proper assy procedure in the first place...but yes -any- slip in there will not work right on the road, and wear out the function of the bushing very prematurely, I would think...I would go as far, if I was pushing them on, to rough up the old polished surface to further prevent ANY movement.

Use a KY or similar water based lubricant.

Thanks for all of the input. I did end up pressing them on dry. Just took my time to make sure that they were going on square and not crooked. Pretty straight forward and turned out great!

The bushings are from Mark and top notch. They are extremely tight going on so if you do not have a press, they will never go on.

I'm glad you pressed them on dry. Mark should have included instructions. I would have bought the rebuilt arms. I didn't know until today that Mark sold the bushing kit. I always thought the front bushing was bonded to the arm and the bracket so they could only twist a little but not slip out of the original position.. If I ever found one that would move from the fixed position I considered it broken and replaced it. Putting any lube on this to ease insertion could defeat the role this plays as part of the damping system and ride height.

Nope, its purely a friction fit..i cry a little when I see any lube used on these, or the ancient polished surface from a failed bushing not roughed up just a little.

I agree and the same could be said for many other items we offer. Sadly that will not happen with me at the helm. Maybe someone else will take over for me and provide that.
Say what you will about Carl but he was very good at that. We have over 8k sku's and cant keep up with just pictures.

are you guys saying that you think that the control arm bushing surfaces should never move at all relative to the "hole" in the control arm or the shafts?

I installed new upper control arm bushings recently (poly), and used lubricant. When I bolted the arms up, they were almost impossible to move up or down...far more "rigid" than they were with my old pos bushings. In any case, if a bushing can't move in the housing or around the shaft, it would have to be installed at pretty much a very specific factory spec angle.

When a car is moving at 100 mph and hits a bump, I don't see how that peak force can not cause a small bit of movement of the bushing relative to the inner or outer surface. That force could easily be far more than the peak force applied when using a press to install them. When you jack up the front end and let it back down and you have to drive it for 5 days to get it to settle, the settling can only be due to the shock and/or movement of the bushings, right?

100% correct. That is their design on a 928 LCA. They are _significant_ spring rate to the suspension.

Ya..and..lord knows why. The uppers are not spring rate, but they do "crush" with decades of age, new ones wont wander a street car alignment, and poly bushings are no longer noise/vibration dampers.

There's a reason poly kits are not on the vendors' WWW pages.

And before you say "I dont feel any"..its cumulative, do one small set, then another..and another...it adds up.

Put on a new LCA, then stand on it.

And "5 days"..it will settle in a few dozen miles on new ones. Quicker if you really feed the car surfaces that will accelerate that.

I cant answer the last half of that well, but still, they do not move.

Look at the install procedure...they are absolutely captive.

Wanna see something cool, cut one in half. its not -a- bushing, but multiple bushings.

https://cimg4.ibsrv.net/gimg/rennlis...a7478f715f.jpg
And brute force, the steel inlet is a PITA