Ford Mustang Forum banner

2001 Mustang GT burning rubber smell (with photos underneath)

6833 Views 7 Replies 6 Participants Last post by  2oo5GT
Hi All. I bought a really nice, clean 2001 GT late July! My first GT!

It's got 49K and a manual transmission. The interior is a time capsule with not a spec of dust.

When I test drove it from the seller almost everything was perfect, drove straight, great brakes, clutch is fine, etc., but it seemed to have a bit of rear end noise, which at first, I thought maybe it was road noise (one tire was missing a balance weight), but then after a while I noticed that it was a consistent whirring at all speeds. So I thought it was a wheel bearing.

I looked all over for any leaks and stuck my head under the car with a flashlight and didn't see anything nasty.

So I took it into a shop to have some general maint., coolant and brake fluid. I told them to take a good look under and around the car for anything that needs attention. They said it was all good... and didn't say anything about the rear end noise.

After a few longer drives at Woodward Dream Cruise, I started smelling something like burning rubber, and it wasn't the tires folks. Wasn't too strong at first, but then this past week it seems to be getting worse. Seemed to be coming from the middle rear of the car, so I looked underneath and noticed what looked like oil or fluid of some sort. I know nothing about the underneath of a car, except for exhaust pipes so pardon my ignorance. Would the Differential be leaking near the exhaust pipes? The photos attached are from the drivers side. And it smells like burnt rubber, which seems like transmission fluid. I didn't notice any drops on the garage floor, but maybe something very slight (not like oil).

Any ideas? I really don't want to take it to a Ford dealer (not too impressed with the one in my area), but I probably should, since they see them most.

Thanks in advance!


See less See more
1 - 8 of 8 Posts
I'm bad with pictures, but maybe pinion seal?

Pinion seal is at the front of the differential case and seals in the diff fluid. It's right behind the pinion flange, which is what your universal joint is bolted to. If your diff fluid is low, your rear end will start making noise.
Start looking at your differential, the leak might be coming from there. Maybe the previous owner hit something hard and caused it to crack or bend out of shape. The smell might be coming from the differential gears as to where the gears are running dry due to the leak and causing too much friction. Start there.
Don't take it to a dealer. Only thing those places are good for is nothing. Okay, maybe buying a car, but that's it.

You just need to keep looking around under there. I would also suspect it coming from the rearend as others mentioned, but those pictures don't show much besides oily residue on a frame rail. Feel free to post pics of anywhere it looks like it's leaking from, we'll let you know what we think.

Other than that, I would recommend you find a reutable shop local to you for any work you cannot or do not wish to do yourself. Amd fwiw, just because it's a Ford dealer working on a Ford car doesn't mean they won't screw stuff up from time to time and overcharge the crap out of you. Plenty of stories like that around here and elsewhere.
Thanks all! That sounds about right after reading some other threads here and a few other forums. Good to have an idea before going in.
Diff fluid smells like rubber like you smoked your tires. When you round a curd your car may make noise or squeel. But check the diff level on a level surface. I had to get my pinon seal changed out very easy job to do, I think it'a 21/22/23 mm nut you have to remove. But got mind changed out and I notice a big difference in my speeds and turns. But mans does that Diff smell bad. it's clear fluid, not pink or black. I wish you well.oldguy.gif
It ended up being the pinion seals and bearings! Good call to you all. Thanks so much for your help!! Drives MUCH better now.
Diff fluid is not clear. It looks like normal gear oil and the bad smell is the friction modifier. Grab a bottle and open will know. I had a few extra bottles in my garage but gave them to a local shop after my garage smelled like crap due to it.
1 - 8 of 8 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.