Diagnosis differential - Anyone agree?

[daluvabull]

Your thoughts please...
Problem:
very loud pop after reverse is engaged; pop when performing a tight turn into a parking lot
Background:
94 LS; transmission rebuilt summer 2006; no tcu lights/codes; minimal rear fluid leakage in driveway
Options:
1. install a used rear differential myself (availability - cost?)
2. rebuild the current rear differential by a shop or myself (likely needed parts?)
Suggestions:
Any suggestions that would enable the repair at minimal cost are solicited and greatly appreciated.

THANKS

Jeff

[Earthworm]

A single noise isn't going to be the diff. Have you checked to see if the transmission mount is worn?

[Hocrest]

Originally Posted by daluvabull

Your thoughts please...
Problem:
very loud pop after reverse is engaged; ...

Does the pop happen before the car moves in reverse?? If so, I would guess a possibal bad U-Joint on your propeller shaft. If you can get the front or rear up on ramps, you should be able to get under enough to check them.

Popping on turning could be a bad CV shaft.

Can you walk besides the car with someone else driving slow to help isolate the noise to front/rear and left/right???

[daluvabull]

tight turn pop:
has only happened once
reverse pop:
happens about every 6 times reverse is engaged
after going in reverse about 10 ft
it is loud - as though something has been it
it seems to be coming from the rear

This is the 94 I sold my brother. I am relaying the symptoms he has conveyed to me.

We sincerely appreciate any assistance that is provided.

Thanks again

Jeff

[Earthworm]

Is there a buzzing sound accompanying it? The ABS will perform a selfcheck once the vehicle passes a certain speed after startup.

[daluvabull]

Brother said he did not notice a humming sound.
He did mention that it would not move backwards until he pushed the accelerator. It seems to drag until the pop and the brakes seem to release. He stated that the brakes pads may need to be replaced. New rear calipers and pads were put on Spring- 05.

[Hocrest]

Originally Posted by daluvabull

reverse pop:
happens about every 6 times reverse is engaged
after going in reverse about 10 ft
it is loud - as though something has been it
it seems to be coming from the rear

If he continues going straight in reverse, does the noise continue? If so have him measure about how many feet between noises.

[daluvabull]

just one pop in reverse

[Hocrest]

I'm thinking propeller shaft or one of the trans mounts that EW suggested????

Get it on ramps and get underneath to give it all a good inspection.

[daluvabull]

How would one inspect the propeller shaft and transmission mount once the car is lifted?

Thanks- Jeff

[Stevebsy]

Sounds like the ABS self-test to me, especially if that is the only time it is making noises. Since I drive my SVX so little thesedays, I'm always 'WTF??' then oh yeah..ABS.

[Hocrest]

Well there is no ABS in my SVX but my 97 Legacy has only ever made ABS noises when I brake hard on slick surfaces. I though the systems were about the same?? I don't know now, does the SVX ABS make other noises???

To check the prop shaft, spend your time looking at the U-Joints at each end. You should be able to turn the whole shaft about an 1/8 turn or so, but the U-joint should move together. Also get a screwdriver in the joint and gently pry to check for play.

At the rear end of the trans there are two rubber blocks between the trans and the crossmember, the blocks should be solid and intact. Try to move the tail of the transmission around to see how the blocks react.

[dcarrb]

Originally Posted by daluvabull

He did mention that it would not move backwards until he pushed the accelerator. It seems to drag until the pop and the brakes seem to release. He stated that the brakes pads may need to be replaced. New rear calipers and pads were put on Spring- 05.

Does he set the parking brake? Could be surface corrosion binding the shoes to the drum 'til it starts to roll and releases with a pop. My silver did something like this recently after sitting inactive for a few days, and that's what it sounded and felt like to me. Wasn't a loud pop, though. For what it's worth...

The pop heard in a turn might be unrelated.

dcb

[Suby Fan]

sounds like a abs self check to me get those back wheels in the air and see if the rear caliper isnt sticking... or if the parking brake system isnt locking up