Noise From Rear Suspension

[alicarmar]

On very rare occasions I hear and feel some sort of binding in the rear suspension. It typically happens when I start from a stop and make a left turn. I've been under the car and can't see any evidence of problem. The ride height is correct and the car handles great.

Other notes: I purchased the car as a roller and have not changed any of the suspension settings with the exception of the front and rear alignment. The car is equiped with the ERA suspension, and it's new to the road with 350 miles.

Any suggestions???

Thanks.

[strictlypersonl]

It's probably the Powerloc (limited slip) binding. Drive it a bit more to break it in. If it continues, change the differential lube to the GM additive as described in the manual.

[Ron Going]

My FIA has the same noise on occasion. Rarely, but if it is going to happen it is from a stop sign, turning left. I agree with Bob's diagnosis. Doug mentioned the same thing to me when I talked to him about it last year. My car has 2200 miles on it. My car was a roller also, so I'm sure the correct oil is in the rear end.

[Tongue Pirate]

The GM Additive is the fix. I added it day one & have had no symptoms yet.

[WV66AC]

My old car had a squeak - from behind the steering wheel it always sounded like it was the right rear passenger side brakes or differential. Went to a shop - took the rear wheel off, etc. - Still squeaked -- turns out it was the front strut bushings. If you have a new car - that probably isn't the problem -- but - have somebody else outside the car listen while you make it squeak -- could be something in the front suspension.

[alicarmar]

I changed the fluid last weekend, added two tubes of the GM additive when I re-filled and the problem is solved.

Thanks for the help!

[strictlypersonl]

You mean I was right?

That spoils my perfect record.

[REDSC400]

Awww come on now Bob.... You Still Dee Man!
BTW, Amalie makes a differential lube additive as well.

[patrickt]

I have the same ratchety noise problem in my ERA rear. From the manual:

Differential: The filler and drain plugs are ½” square. Fill
with Moroso climbing gear lube, SAE 90, part number
34800, mixed with 4 to 8 oz. of Amalie limited slip additive
(part # 505-6775). If the above are not available, you may
use 80W-90 GL5 lubricant with an equivalent limited slip
additive. If the limited slip seems to be sticking (ratcheting
around sharp corners), drain and refill, replacing the
Amalie additive with 2 tubes of GM additive 1052358.

Question: Is there any danger in overfilling the differential and stressing the seals? Or do you just take it up to the bottom of the fill hole and that's it.

[strictlypersonl]

Assuming the car is on a level surface, just fill to the bottom of the hole. Much more and you might see the excess oil on the floor eventually.

[patrickt]

Originally Posted by strictlypersonl

Assuming the car is on a level surface, just fill to the bottom of the hole. Much more and you might see the excess oil on the floor eventually.

Thanks. That "other" car company (which was my runner-up to an ERA) had the following bold warning:

Warning: The differential covers that we use locate the drain plug approximately an inch higher than the original covers. (Original style covers are no longer available.) Do not fill the differential to the drain plug or it will cause heat and high pressure in the diff and blow out the seals.

[strictlypersonl]

We use the original steel cover so that isn't a problem with us.