Gear Oil Smell

[THark88]

First, i'd like to introduce my self ! HI, LOL. car is a 2001 vert with just shy of 85k miles. Texas car.

i have not had the car long and have only put 600 miles give or take on it since i've owned it. it's in VERY good shape. But i have noticed that on the freeway if i cruise at 75+ after a few mins i smell gear oil. We all know that gear oil has a distinct smell and i'm 90% sure that is exactly what i'm smelling ! i can not figure out what is going on. Does anybody have any ideas?

i also notice that if i really get on it, and hold her above 4500-5000 RPM i smell something "hot". i'm not sure if burning smell is the right thing but... almost. this happens whether i hold the RPM or shift. again, this is only if i'm getting on it hard.

thoughts ?

PS: been monitoring the site for quite a long time, so thank you all LOL

 

[DSG2003Mach1]

Have you checked around back there for any sign of a leak at the diff cover, pinion seal, breather or axle seals?

 

[THark88]

i was under it a few days ago (replaced clutch) and looked all around. not specifically for this issue but just because. didn't see anything out of the norm. i figured i will need to get under the rear tonight. i've never worked on an IRS so, not sure where the vent tube goes or anything.

 

[01yellercobra]

The vent tube is on top of the diff. It looks like an upside down J. Check your tailpipes. If it's blowing out of the vent it'll be all over the pipes. Was any work done recently on the diff? Did anyone add oil? Check the pinion seal.

Just check around for wiring that's moved. Or for something that might have gotten onto the exhaust. You could also be smelling the cats. If you still have them that is.

 

[THark88]

i'll check this evening. no work done besides new clutch last weekend. nothing from the trans back though.

i have no cats (new prochamber last week)

i'll check for wiring as well !

 

[01yellercobra]

Did you change the tranny fluid while you were at it? I usually give it a couple days when I've moved exhaust and stuff. You'd be amazed how much grease and stuff gets on it from working under the car. You'll smell it burning off for a bit.

 

[THark88]

Yes we replaced the trans fluid with new fluid.

 

[THark88]

Looks like I found the cause of the smell. I'm going to assume I now need to drop the irs and replace/reseal the diff cover ?

 

[THark88]

Here's the diff. Looks like it's leaking onto the exhaust. Crazy there's nothing in the garage tho

 

[THark88]

Here's a look at some of the busbings in the irs though. Not happy. Haven't had the car a month yet.

 

[01yellercobra]

You've only had it a short time. But the car is 18 years old and has 85K miles. Welcome to the joys of older cars.

Yes, you'll have to drop the diff to seal the cover. At the very least I would get a diff brace while it's out. Even better would be a better cover. You can also upgrade the diff bushings while you're in there. It's not too bad if you go poly. The only other thing I would suggest is getting the torque brace like what comes on the 03/04. It has a couple extra tabs that go under the diff ears to support it better. It makes getting the diff in and out a little more of a pain, but the extra support is worth it.

 

[shurur]

You've only had it a short time. But the car is 18 years old and has 85K miles. Welcome to the joys of older cars.

Yes, you'll have to drop the diff to seal the cover. At the very least I would get a diff brace while it's out. Even better would be a better cover. You can also upgrade the diff bushings while you're in there. It's not too bad if you go poly. The only other thing I would suggest is getting the torque brace like what comes on the 03/04. It has a couple extra tabs that go under the diff ears to support it better. It makes getting the diff in and out a little more of a pain, but the extra support is worth it.

OP,
These suggested mods are mandatory or you will likely be revisiting this again.
diffy torque brace
New beefier Ford cover
poly or solid AL diffy mounts.
and if diffy is leaking, new pinion and axle seals...
Hell, get a Detroit true track differential and gears while you are there...

I have MM diffy poly mounts and the steeda cover brace for my OEM IRS cover..a cover with no drain I might add.. .
I plan to put in the older style MM AL diffy mounts.. mounts that do not clear the better beefier diffy ford covers. I do this only because I have already bought them years ago and MM will not let me turn them in for an upgrade to the ones they make now (now that FTBR makes them) to clear the beefier ford diffy cover.

I also have a cobbled together IRS upgrade kit from various vendors...MM...steeda...

My advice is to get the aforementioned mods from FTBR and be done with it.
Get the whole IRS upgrade shebang..save up for it..and be done with it.

And I say this while owning nothing from FTBR on my car!!

 

[THark88]

So it looks like it'll be a month or so before I get it all, never knew bushings kits could be so dang exoensexp!!

 

[shurur]

So it looks like it'll be a month or so before I get it all, never knew bushings kits could be so dang exoensexp!!

You can do the (FTBR) IRS upgrades a bit at a time like I did and still am doing...
I under$tand..I had no choice myself..what I essentially have on my Kelly is what was once called the "Red Pill," but WO the 31 spline axles.
When I was fixing my IRS in 2007, FTBR was still young.

read these:
IRS Informational Article
https://www.svtperformance.com/threads/the-irs-tech-article.213384/

Consider stiffers or global west subframes at some point..especially for the vert..vise FLSFCs.
Reference the FTBR article above.

We "poor folk" have to "enjoy the journey/process."
You are not alone here.
Welcome.

 

[black4vcobra]

Late to the party but I also had a leaking cover once upon the time. I also did MM diff bushings, Billetflow diff brace, 03/04 torque brace and a new pinion seal. Another thing to consider is getting a lubelocker gasket though I was able to seal my cover with Permatex ultra grey and it hasn't leaked in over 6 years.

In hindsight, I would have sprung for the Ford Racing cover to have a drain plug.