Smell hypoid oil

Kilroy

Adventurer
Every time I drive my 2000 TJ with 4.0 and automatic I smell hypoid gear oil when I park in the garage. This has been going on for at least 8-9 months. There are no leaks from the differentials, fluids were changed this summer. The transfer case has some leakage, it gets caught in the belly pan, but it is not hypoid gear oil and doesn't smell like it either. Any suggestions?
 

Kilroy

Adventurer
I had the diff covers off and cleaned and changed fluid. Had smell before and still have smell. No sign of leakage at the diff covers.
 

Grim Reaper

Expedition Leader
You sure the smell isn't in the garage and nothing to do with the truck?

Got and IR thermometer? See how hot the Diff is getting. 150-160f is about normal after a long hwy run, above that may indicate a problem. Also look in the wheels and brake drums. Bad seal at the axle shaft will leak into the brake drums and can be a fire hazard.
 

Tucson T4R

Expedition Leader
OS-Aussie said:
check to see if there is fluid coming out of the breather pipes, this can often happen with ARB's

Also, check at the ARB compressor. On my 90 4Runner with ARB locker, I got some diff oil back up the air line and it leaked a bit at the comprressor air inlet. That only happened if I didn't run the locker for a long period. Once I got in the habit of cycling the locker at least every couple weeks I didn't experience the oil migration any more.
 
Kilroy said:
I had the diff covers off and cleaned and changed fluid. Had smell before and still have smell. No sign of leakage at the diff covers.


How about the axle vents? Any leakage there?

Do you have a new style 2 piece case ARB or the old style, circa pre 2004?
 

madizell

Explorer
Tucson T4R said:
Also, check at the ARB compressor. On my 90 4Runner with ARB locker, I got some diff oil back up the air line and it leaked a bit at the comprressor air inlet. That only happened if I didn't run the locker for a long period. Once I got in the habit of cycling the locker at least every couple weeks I didn't experience the oil migration any more.

I have run ARB's now since 2001, and have never had oil migrate back up the pressure line from housing to the compressor. The only way I can imagine this happening at all would be excessive pressure in the axle housing, probably due to heat. If the housing is adequately vented, this should not be possible. I would suggest you check the axle vent and verify that it is working, and not plugged up with dirt.
 

Kilroy

Adventurer
I also smell the hypoid parked outside, so it's not the garage. I don't have an ARB. Will check for leakage from vents and axle seals. Will also check diff temp. How hot should transfer case get? I've noticed it being very hot to the touch after running on highway. Thanks to everyone for suggestions.
 

BigAl

Expedition Leader
any chance you have water in the diffs?, if I get water in my front diff the oil/water blows past my axle seals
 

Kilroy

Adventurer
Changed the diff oil last summer. I was getting the smell before doing so and continue to get the smell afterwards. Thanks for the suggestion. I need to check the seals anyway. Waiting for warmer weather in WI.
 

Forum statistics

Threads
185,529
Messages
2,875,555
Members
224,922
Latest member
Randy Towles
Top