rear suspension noise over tar strips

[911monty]

The car needs to be sitting on all 4 wheels. When you tighten the bolt thru the bushing, the bushing center shaft is held in that position by the bracket. Control arm movement up and down is enabled by the bushing rubber torquing/stretching around that center shaft. When you load the cars suspension before tightening, the rubber bushing is in a neutral/unloaded position. It can then stretch equally in both directions as the suspension compresses or rebounds. If you tighten without loading the suspension then once the car is on the ground the rubber bushing must stretch as the arm is compressed upward. This has the bushing loaded 100% of the time. When you hit a bump and the suspension compresses, the bushing must stretch even further than designed. The only time the bushing is relaxed is when the car leaves the pavement and is flying. Hope This makes sense.

[WillH]

From my understanding it was a bushing until '99 when they changed to ball. The manual also states that the old type are no longer being manufactured. I guess the vertex re-bush ones would count for those.
I can't see the ball being loaded or unloaded as it can be moved by hand. So I guess I'm saying that this doesn't make sense to me.

Edit.
Might make more sense for the trailing arm at the control arm, though not too sure about that either.

[WillH]

I'm guessing now that the manual is referring to the coffin arm/control arm as it makes no sense for the trailing arm/control arm.
Looking forward to noise free ride to work

[EJ-Fresno]

Originally Posted by 911monty

The car needs to be sitting on all 4 wheels. When you tighten the bolt thru the bushing, the bushing center shaft is held in that position by the bracket. Control arm movement up and down is enabled by the bushing rubber torquing/stretching around that center shaft. When you load the cars suspension before tightening, the rubber bushing is in a neutral/unloaded position. It can then stretch equally in both directions as the suspension compresses or rebounds. If you tighten without loading the suspension then once the car is on the ground the rubber bushing must stretch as the arm is compressed upward. This has the bushing loaded 100% of the time. When you hit a bump and the suspension compresses, the bushing must stretch even further than designed. The only time the bushing is relaxed is when the car leaves the pavement and is flying. Hope This makes sense.

Yes, it totally makes sense.
I have 2 questions:
- I tightened the bolt without the wheels putting weight on the suspension, does it help?
- If I still have to tighten in loaded position, can I just put the car on stands/loosen the bolt/lift the wheel using a jack/tight the bolt? Or I have to go through the whole process again?
Thanks for your help

[911monty]

Originally Posted by EJ-Fresno

Yes, it totally makes sense.
I have 2 questions:
- I tightened the bolt without the wheels putting weight on the suspension, does it help?
- If I still have to tighten in loaded position, can I just put the car on stands/loosen the bolt/lift the wheel using a jack/tight the bolt? Or I have to go through the whole process again?
Thanks for your help

Hi EJ-Fresno. The intent is to have the car resting on all 4 wheels before tightening. This places all suspension components in their loaded state. You could use the jack under the tires, this will get close, just not perfect. Certainly much better than current! Are you going to have the car aligned? If so then maybe alignment shop can loosen and retighten when car is on alignment rack.

[EJ-Fresno]

Originally Posted by 911monty

Hi EJ-Fresno. The intent is to have the car resting on all 4 wheels before tightening. This places all suspension components in their loaded state. You could use the jack under the tires, this will get close, just not perfect. Certainly much better than current! Are you going to have the car aligned? If so then maybe alignment shop can loosen and retighten when car is on alignment rack.

Will do my low-cost way and then get an alignment done to fix any deviation.
Thanks again for all the help!

[KRAM36]

Originally Posted by 911monty

The car needs to be sitting on all 4 wheels. When you tighten the bolt thru the bushing, the bushing center shaft is held in that position by the bracket. Control arm movement up and down is enabled by the bushing rubber torquing/stretching around that center shaft. When you load the cars suspension before tightening, the rubber bushing is in a neutral/unloaded position. It can then stretch equally in both directions as the suspension compresses or rebounds. If you tighten without loading the suspension then once the car is on the ground the rubber bushing must stretch as the arm is compressed upward. This has the bushing loaded 100% of the time. When you hit a bump and the suspension compresses, the bushing must stretch even further than designed. The only time the bushing is relaxed is when the car leaves the pavement and is flying. Hope This makes sense.

Didn't even think about this. Good bit of advice. Would putting some jack stands just on the suspension and lower it mimic the car sitting on the rear wheels?

[Pdwight]

Kram I had to do this to get the bolts in the rearmost attachment point. I put the arm in place and the front tough bolt and then jacked up the rear link just inside of the rotor until the holes lined up.....the car was all but fully supported when I did this by the jack under the rear link.......this has been a great thread.

Back when I was doing this a member on here gave me the 987 part #s for the arms, he said they were built much sturdier than the 986 arms and he was a regular tack guy as memory serves me.

[911monty]

I have seen cars that were several inches over their stock height after suspension rebuild because they tightened their bushings while on jack stands. The bushing becomes a rubber spring!

[KRAM36]

Originally Posted by Pdwight

Kram I had to do this to get the bolts in the rearmost attachment point. I put the arm in place and the front tough bolt and then jacked up the rear link just inside of the rotor until the holes lined up.....the car was all but fully supported when I did this by the jack under the rear link.......this has been a great thread.

Back when I was doing this a member on here gave me the 987 part #s for the arms, he said they were built much sturdier than the 986 arms and he was a regular tack guy as memory serves me.

Excellent. I have mine sitting here. Just waiting on the new struts and shocks to get here before I start, already have new springs waiting too. You're right, great thread.

[911monty]

If you can, while using jacks under the suspension is certainly better than tightening with wheels off the ground, having your wheels on and resting level on ground, ramps or lift is ideal. Reason being different wheel widths and offsets will have an effect on the leverage placed on the wheel bearing and suspension. While minor compared to being off the ground, for PERFECTION have wheels on. This will keep your alignment much longer due to less suspension settling.

PS: Don't even get me started on how bad wheel spacers are for your wheel bearings!!!

[KRAM36]

Originally Posted by 911monty

If you can, while using jacks under the suspension is certainly better than tightening with wheels off the ground, having your wheels on and resting level on ground, ramps or lift is ideal. Reason being different wheel widths and offsets will have an effect on the leverage placed on the wheel bearing and suspension. While minor compared to being off the ground, for PERFECTION have wheels on. This will keep your alignment much longer due to less suspension settling.

PS: Don't even get me started on how bad wheel spacers are for your wheel bearings!!!

What about the nose being angle down? Should I also get the front wheels level to the rear wheels?

[911monty]

Originally Posted by KRAM36

What about the nose being angle down? Should I also get the front wheels level to the rear wheels?

Kram; Level is best if possible. But as EJ-Fresno noticed the jacks will certainly be better!

[RandallNeighbour]

Originally Posted by 911monty

The car needs to be sitting on all 4 wheels. When you tighten the bolt thru the bushing, the bushing center shaft is held in that position by the bracket. Control arm movement up and down is enabled by the bushing rubber torquing/stretching around that center shaft. When you load the cars suspension before tightening, the rubber bushing is in a neutral/unloaded position. It can then stretch equally in both directions as the suspension compresses or rebounds. If you tighten without loading the suspension then once the car is on the ground the rubber bushing must stretch as the arm is compressed upward. This has the bushing loaded 100% of the time. When you hit a bump and the suspension compresses, the bushing must stretch even further than designed. The only time the bushing is relaxed is when the car leaves the pavement and is flying. Hope This makes sense.

Thanks so much for this explanation. It makes a lot of sense to me and may be the reason some of my control arms have worn out prematurely. They were not tightened under load.

[911monty]

Originally Posted by RandallNeighbour

Thanks so much for this explanation. It makes a lot of sense to me and may be the reason some of my control arms have worn out prematurely. They were not tightened under load.

Thanks RandallNeighbor, Glad to be able to return a small ripple of benefit to the sea of information yourself and the many other members have provided by their time and experience to this forum. To quote Retroman "Remember we're all in this together"!

[Pdwight]

Anyone used these ?