Rattling noise - Don't think it's engine mounts

[bvmags]

Hey all, newbie here and have a question. My 300e makes a rattling noise that sounds like it's coming from towards the rear, and it only rattles when I'm coasting or braking. It does NOT rattle when I'm accelerating or idling. Any thoughts on what this could be? I've searched the forum, but all the "rattling" references don't seem to be the same problem as mine. Mine distinctly only happens when coasting or braking. Seems odd.

My friend thinks I need to replace the axle assembly, but just wanted to see if anyone else has experienced this before I fork out the cash to replace it. Thanks in advance.

-Brian
'89 300e

[Inline6]

Transmission support??

[nickCR]

I would suggest you check your transmission support however the spare tire and the jack if not fastened correctly will MAKE that rattling noise. I have the same problem but it's because of my sub-woofer box.

[bvmags]

Thanks for the responses. Is the transmission support the same as the transmission mount? (part no. 1242400618).

Thanks again

-Brian

[chrisdpham]

Is your shifter loose?

If so - it could be your shifter bushings that went out and needs replacement.

Also check the rear end and see if your control arm is broken.

[bvmags]

Hey all, thanks for the ideas.

My mechanic friends has checked out the car, and I showed him all your replies and he's pretty sure it's not any of the suggestions you gave. BUT, he's still stumped.

Here's some more info:

We tried the axle route. We jacked the car up, took off the tire and axle, started the car up, stepped on the gas, and no more rattle! Naturally, we thought it was the axle. So we proceeded to replace it. Once we put the new (used) axle and tire back on, back came the rattle.

Again, it's only when I let up on the gas. If I'm coasting = rattle. If I step on the brake = rattle. If I step on the brake AND give it a little gas at the same time = NO rattle.

We took off the heat shield and we really couldn't pinpoint exactly where the noise is coming from. The differential is running oil through it, so we pretty much discounted that as the problem (should we have?).

Any other thoughts? I think I'm just going to have to pony up at the dealer for a diagnosis.

[GHM]

Just a shot in the dark, could be the catalytic converter, when they start to go out they sometimes rattle. Just a thought.

[bvmags]

Hey all,

Just an update, in case anyone is interested. The noise turned out to be the differential. My mechanic thinks that before the car was sold to me, the seller dumped a bunch of oil into the differential making it seem okay. It turns out that the gears in the differential were severely cracked...actually broken! New differential = problem solved! No more rattling!

[drag1]

have the same problem with my car.

what is the part number for the differential ?? is there only 1 part ??
how much did u pay for the part ??

thx