I was all excited that I purchases a set of urethane bushings from Martin to replace the worn ones in my STR. I had another set of SC control arms that I installed the bushings in. This morning I decided to put in the arms with the urethane bushings. It took about 2-1/2 hours to install both lower control arms.

Now it was time for a test drive. OMG! Simply horrible! As I accelerated, the rear of the car started weaving back and forth. When I hit about 45mph, the rear tires started making a singing noise. As I turned a corner the car was very hard to control without the rear-end weaving back and forth!

These bushing must be way to soft! I believe that Martin purchased them from a guy on E-bay. This item is unsafe! Never have I had urethane bushings feel so squishy.

Now it is back out to the car to put back on the old control so I can drive the car!

 

I would imagine that there was either an installation error or a need to redo the wheel alignment, but in general poly bushings are one of the dumbest ideas to ever come along. They're not an upgrade in my mind- but a downgrade instead.

Never again...........

 

I just got back from having the rear toe-in/out alignment done. Both wheels were significantly out of toe. (I should have thought of this before my first post)

The car drives better now, but I don't like the new side-to side "Mushiness".
I'll keep the bushings in for now, but will take the time to rebuild the original rear control arms with stock bushings.

One interesting thing to come out of this, While they were re-aligning the rear wheels, They noticed that the left rear camber is off by 2.6 degrees. Either bad upper control arm inner bushings, or the strut has problems...

It looks like all 4 of my struts are leaking as well. Dang!

More things to look into....

 

Another quick update: I needed new front tires, so I had them installed this afternoon, along with a full 4 wheel alignment.

The car is drivable, but I am still unhappy with the characteristics of these urethane bushings. On smooth roads the car drives ok. But when I hit a bump or depression in the road, the back of the car hops around, with a little side-to-side motion before smoothing back out.

I'm going to contact the manufacturer and find out what's up.

 

Yesterday I put back on my original lower rear control arms, and adjusted the toe back to its original position. The car is back to is old self.

In the week I ran these bushing in the car, I probably scrubbed of 1000 miles off the rear tire. The back of the car was covered with rubber powder!

I've sent 2 E-mails to the UK Ebay seller of these bushings. No Response.

Here is the link to the Ebay seller:

Jaguar S-Type REAR Lower Wishbone Poly Polyurethane bushes | eBay

I hope everyone on this forum reads these posts and never purchases this product. It is literally unsafe to install this particular item! The durometer of the urethane used is way too soft. Add in the Large 47mm OD of our bushings and there is way to much flex and motion. So much, that the wheel/tires move all over the place!!!

Live and Learn!!!