Did the polygraphite front bushings install - My thoughts

[CarreraS2]

After researching this topic and thinking about it for a couple of months, I decided to go ahead and install the PGs that I had sitting on my workbench.

Looked at the other options - Elephant, needle bearings, trying to force stock rubber ones back on, etc. But decided to give the PGs a try, since I already had them, and all of the other solutions seemed less than perfect (or too costly, like replacing the a-arms with new ones, or Smart rebuilt ones).

My observations. These may be obvious to some, but hopefully helpful to others:

1) It seems to me that milling the OD is wrong. It also seems that a lot of Pelicans who have tried that have come to the same conclusion. Although the Smart Racing website seems to suggest it could/should be done.

The reason the PGs come so thick is because the brackets that hold the bushings are terribly out of round. This can easily be seen by pushing the bushings into the bracket. The ID hole becomes visibly unround. When you measure it, you see that it can be pretty dramatic.

The A-arm where the bushings ride (where the ID of the bushing contacts the A-arm) is a precision part and is very round.

So the theory seems to be to make the bushings extra thick. You then install the bushing into the imprecise brackets/retainers. This squeezes them down into their irregular shape. But because there is extra material, you can mill it out to make it perfectly round, and to fit the A-arm perfectly.

Now, I know a lot have done this by using a broom handle and sandpaper. To test that, I tried it on one of the ones that was the easiest to do (i.e. was already the closest fit before starting). I used a jack handle, which was thicker than a broom handle and very close fit in the bushing. To my eye, it looked like it came out very round and ok.

Then turned it over to my buddy with a machine shop. The one that I did that looked and felt ok was not. It in fact was out of round. The lathe cleaned that up. The others needed significant material removed to make them round and to open them up enough get the proper fit onto the a-arm. Easy work for a precision industrial lathe. Impossible to duplicate by hand.

Conclusion: Don't mill the outside of the bushings! That defeats the purpose. If you want to do it right, IMO you really need a proper lathe to do the ID. Yes, you can get the bushings on the car by hogging them out by hand with a broom handle, dremel, etc. etc. but you aren't going to get it the way it really should be for best results.

2) These bushings definately need grease to not squeek. You can just grease them and be done with it, but it does seem worth putting a groove in for grease, and a zerk fitting. These are very easy to do. It also seems to me that using a radial groove, rather than the lateral groove that most seem to use, is far more effective at distributing the grease.

It was easy to cut the radial groove with a dremel and the proper grinding wheel attachment. Fitting the zerks only takes a couple of minutes with standard 6mm zerks available at the local Ace hardware. Seems silly to not do it while you are in there.

With the radial groove and zerk, when you force grease in, it will have nowhere to go but all the way around and through the bushing. With the lateral groove, it will fill the groove, but then simply ooze out of the opening at either end. The grease won't be forced anywhere. Better than nothing, but doesn't seem optimal.

Using the above, I got a good fit of the bushings onto the a-arm. Tightening it down onto the car did not cause any binding of the a-arm. It is snug, but rotates up and down with easy pressure, smoothly and with no binding.

At this time, there are no squeeks. I'm keeping my fingers crossed. But the above seems to me to be the best way of getting squeek free PG bushings for an extended period of time.

[Wil Ferch]

keep us posted periodically how it holds up / ages......

Wil

[jester911]

Any pics of your work?
I bought these bushings a while back and they have been sitting on my bench the same way yours did. I have been considering options for a while now.

[Bill in OKC]

Originally posted by jester911
Any pics of your work?
I bought these bushings a while back and they have been sitting on my bench the same way yours did. I have been considering options for a while now.

There is a lot of us in the same boat isn't there? But we are in good company then LOL

[RoninLB]

I bullied the job about 5yrs ago way before Elephant Racing existed.

I used that clear expensive bushing grease. It's like gorilla snot. Almost can't get it off your hands.

Just starting to squeak slightly during winters after 50k mi.

It seems from listnening to pelicanheads that a squeak is a 50/50 chance.