smell of gear oil after driving

[stangnut]

ok- i had 4.10's installed on my car about 4 months ago and i really like the difference they made.--BUT--after running my car,back and forth to work(about 60 miles) i can smell gear oil when i park it in the garage. at first i thought maybe some had gotten on the exhaust and was burning off,but after all this time that should no longer be the case. there is no leakage that i can tell and no whine from the gears, so what could it be? my mechanic said that he thought that there were "vents" somewhere on the axle and thats where the smell is coming from--is he full of caca?:shrug:

 

[STAMPEDE3]

Nope he is not, there is a vent.

 

[stangnut]

so i guess this normal? i was more curious than worried about why this would occur.

 

[STAMPEDE3]

Smelling it is not what I call normal.

The fact that there is a vent is normal but if your smelling fluid then it is building up a lot of pressure or is getting hot or something.

Sounds like there is a issue but hard to tell what it is over the net.

 

[Slow95Cobra]

+1, i would be lead to beleve the axle seals or pinion seal leaking... ive never smelled anything from the tiny little vent in all my years at a dealer

 

[Doug]

have you checked to see if actually has oil in it?

 

[Toasty]

Smelling it is not what I call normal.

The fact that there is a vent is normal but if your smelling fluid then it is building up a lot of pressure or is getting hot or something.

Sounds like there is a issue but hard to tell what it is over the net.

Overfilled and pushing out the vent?

Vent partially plugged and oil coming out when temps get high? The vent is located where the rubber brake line from the chassis meets the hard lines on the axle IIRC. The vent itself is a banjo-style bolt I believe with a small vent cap on top.

I'd start with checking fluid level in the axle. If you dont know how to do this, buy a Hanyes/Chiltons manual and read up a bit (hint: its very easy to check). I'd then check the vent.

Whats also possible is that your mechanic spilled some gear oil on the pumpkin when he was filling it. Once the pumpkin gets hot, you will end up smelling the gear oil that has saturated the cast iron pumpkin as it slowly cooks off.

Did your mechanic change the gear oil in your diff after a couple of hundred miles of the new gears being installed? Good shops will perform this as part of the gear install, and they usually use the opportunity to double check backlash, torque on the diff main caps and pinion nut.

 

[stangnut]

Overfilled and pushing out the vent?

Did your mechanic change the gear oil in your diff after a couple of hundred miles of the new gears being installed? Good shops will perform this as part of the gear install, and they usually use the opportunity to double check backlash, torque on the diff main caps and pinion nut.

never offered or mentioned this! but i think it would be a good idea to have him do it!! i haven't noticed any leakage at all nor is there any whine so i didn't know what to expect/accept as normal. used royal purple gear oil,new gears(frpp) and complete bearing/seal set also changed over to an frpp aluminum driveshaft. i'll have him check it out! thanks !!!

 

[01cobravortech]

Somewhat related. When I did 4.56s on my 01 Cobra I had the same gear oil smell. Turns out that gear oil was going through the vent hole. Eventually it stopped when the correct level was reached by itself. Initially I thought there might have been some bad seals where the half shafts are inserted. But bending underneath the car I could see it all over the back of the diff cover.

 

[stangnut]

guess i need to crawl underneath it and have a good look

 

[Toasty]

never offered or mentioned this! but i think it would be a good idea to have him do it!! i haven't noticed any leakage at all nor is there any whine so i didn't know what to expect/accept as normal. used royal purple gear oil,new gears(frpp) and complete bearing/seal set also changed over to an frpp aluminum driveshaft. i'll have him check it out! thanks !!!

At teh very least, the gear oil should be changed after a couple of hundred miles AFAIK.