Trailing arm w/bushing to tight for chassis mount :-(

[Zithlord]

I bought the OEM inner trailing arm bushings from Pelican and installed them with a press(901-331-059-00-M100). The problem is that the rear trailing arm is now 3mm to wide for the chassis mount(inside diameter of the mounting bracket is 3mm to narrow) any trick to get the trailing arm into the mount? I wonder if the powder coating can be the cause, can the powder coat bild that much extra thickness? I hope I do not have to destroy the bushings and buy new ones.... Please see pictures

Thanks
John

[Zithlord]

I tried to squeeze first with a wise, but the end going towards the chassis mount actually widened when I sqeezed the opposite side. Then I tried a 6mm bolt with washers in both ends and sqeezed the needed 3,5 mm. This time it actually fitted, but I could only enter 1/3 of the mount because of the bolt, and when I tried to remove the bolt it pooped out again.

John


Got it Raj, will get back to you when home from the office

[chris_seven]

What year is your car?

The most common dimension for the trailing arm mount is 55mm between the faces of the mount and normally the bushes clamp up to this dimension. It is normal that they may only clamp in to about 56mm so you may have to fight them a little.

If you have a SWB car the 'clevis' may be about 1.5mm wider and it is a little less rigid than the later cars so it may be easier to force it into place.

If you measure one of the bushes before it is installed into the arm they are about 27.3mm long so in theory they don't quite touch in the middle of the eye.

If you have powder coated the arms inside the eye then the tolerance ring (inner steel sleeve) will crush more than it should and this could force the rubber out and make the bush too wide. I don't think thepowder coating has made the arm too wide I think the eye is too small a diameter.

I am sure you are aware that the rubber is not bonded in this bush and it is held together by the radial expansion caused by pressing the assembly together.

I guess the problem now will be to take out the bushes without the inner steel housing sticking in the eye end, this would allow you to remove the powder coating and make the bushes fit more easily.

I think you may need to find a bigger press to push them back into place so that you get them as close to the 55mm distance you need.

Good luck

[Zithlord]

Did it!

I used the long 6mm bolt with washers on both sides, then entered the trailing arm inner end 1/3 into the mount, then fastened a C-clamp on the outer part. Then I secured the trailing arm to the torsion tube with steel wire. After this I removed the bolt, and wrigeled the arm a little bit further in, until it stopped against the C-clamp. Now it was 1/3 inn. I tightened the steel wire, removed the C-clamp and hammered it inn with a hammer and a long steel rod. Voila, it was in place and I could push inn the bolt.

My car is a 1971 911S. The trailing arms are the originals, and I used a 5 tonn press to fit the bushings. The mount was 5,45mm wide and the asembly was 5,85mm wide, but now it is in place.

Phuuu...

John

[Zithlord]

Here are some pictures

[smedley]

I've done three restorations in the last two years. All three sets of trailing arms had new bushings pressed in to the perceived limit, and all three initially appeared "too tight."

By greasing the edges of the bushings flanges and edge of body bracket, compressing the bushings with a C-clamp, and some serious shoving.....I could get the leading edges of each side started into the bracket. Then using first an awl and then a tapered punch I could pry through the bolt holes, and get final position and bolt alignment.

Yes, they seem to be too tight. But remember the forces here and the compliance of the rubber. Nothing is wrong....press on!