bushing issue
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05-26-2011, 11:09 PM
#2
Safety Car
It looks like the snap ring broke or wasn't seated all the way.... I'll bet it's the latter. Did yo do the install yourself? When I did my Pfadts this winter I had to compress the front uppers with clamps to get the snap-ring 100% seated. I thought they were seated, but upon double checking they weren't fully... triple checked it.
05-27-2011, 12:05 AM
#4
Le Mans Master
The snap ring has definitely popped out or broken like travisnd said.
Unbolt both sides of the upper arm, clean the bore and reinstall. 1/2hr job at most.
Unbolt both sides of the upper arm, clean the bore and reinstall. 1/2hr job at most.
05-27-2011, 12:44 AM
#6
if it's a seating issue the snap ring will still be there, but just slid over, if the ring broke, than it was seated, but just broke.
I don't know that this product was engineered perfectly for the application. I keep a close eye on mine though.
I don't know that this product was engineered perfectly for the application. I keep a close eye on mine though.
05-27-2011, 01:08 AM
#8
Safety Car
05-27-2011, 07:41 PM
#11
Hey guys. The Inner diameter tolerance on the control arms from GM is pretty wide, this makes manufacturing a poly bushing for these arms pretty tough since you need to make a bushing that fits securely into a wide range of control arms. From GM's perspective since they are installing soft rubber bushings into the control arms, so inner diameter doesn't matter too much since the stock rubber bushing is going to compress easily when installed into the arm. With polyurethane we are trying to eliminate deflection, and since poly in this application has a much higher durometer than the stock rubber bushing those wide ranging tolerances must be accounted for by a bushing that isn't so big as to not fit into the smallest toleranced hole, but not so small as to not fit snugly into the largest toleranced hole.
The particularly tough installs come on cars whose control arms have smaller inside diameters. When you press the poly bushing into the arm the poly will actually compress and elongate a bit, and since this is a 2 piece bushing there is a chance that the 2 halves can meet in the middle. If your bushings have met in the middle, and under hard braking you add more compression which squishes those bushings even farther, that material has to go somewhere. In this case that material can force the washer into the snap ring, and force it to pop out of it's machined groove in the pin and cause this.
If you see this happening there are some things to do to prevent it:
1. Make sure that the flat inner edge of the D Shaped washer supplied with the kit rides securely on the pin, preventing the washer from spinning.
2. Confirm that the snap ring is seated securely in it's machined groove on the pin. This can be tricky if your control arms have a tight tolerance.
3. If your seeing the bushing walking out after a track day, it's perfectly OK to remove a small amount of material from the inside face of both poly bushings at the effected attachment point. You will most likely see this happening on the front upper control arms, at the inside 2 halves of the poly bushings. This is shown pretty clearly by the pictures above. Removing some material from the poly bushing allows the poly somewhere to go while it's being compressed under hard braking and will prevent this from happening.
If you guys have any questions or concerns please feel free to contact us! We are open 9-5 Mountain standard time at 888-972-2464 and are always here to help!
The particularly tough installs come on cars whose control arms have smaller inside diameters. When you press the poly bushing into the arm the poly will actually compress and elongate a bit, and since this is a 2 piece bushing there is a chance that the 2 halves can meet in the middle. If your bushings have met in the middle, and under hard braking you add more compression which squishes those bushings even farther, that material has to go somewhere. In this case that material can force the washer into the snap ring, and force it to pop out of it's machined groove in the pin and cause this.
If you see this happening there are some things to do to prevent it:
1. Make sure that the flat inner edge of the D Shaped washer supplied with the kit rides securely on the pin, preventing the washer from spinning.
2. Confirm that the snap ring is seated securely in it's machined groove on the pin. This can be tricky if your control arms have a tight tolerance.
3. If your seeing the bushing walking out after a track day, it's perfectly OK to remove a small amount of material from the inside face of both poly bushings at the effected attachment point. You will most likely see this happening on the front upper control arms, at the inside 2 halves of the poly bushings. This is shown pretty clearly by the pictures above. Removing some material from the poly bushing allows the poly somewhere to go while it's being compressed under hard braking and will prevent this from happening.
If you guys have any questions or concerns please feel free to contact us! We are open 9-5 Mountain standard time at 888-972-2464 and are always here to help!
Last edited by Pfadt Racing; 05-27-2011 at 07:44 PM.
