Hot, smelly G80 Locker??

[GMC D-Max]

I did a quick search about the G80 and overheating problems, but my specific concern is the smell of hot gear lube after even short trips.
I took a trip east of the mountains last weekend (about 800 miles round trip, unloaded), and ever since then, I'm smelling hot lube at the back of the truck. After a short trip yesterday, I could smell it again, so I crawled under it and felt the back cover of the diff. It wasn't HOT, but I thought it was a little warmer than it should be, considering how short of a drive it was.
I changed the lube at around 1000 miles (Amsoil 75w90, 4 qts.), and the truck now has approx. 14,500 on it. I very occasionally put a 3500# camper on the truck, but not often enough to warrant using 75w140 (IMO). Any ideas on this? Or should I just get used to it?

[FirstDiesel]

I'm running the same lube you are and never notice any smell.

[NWDmax]

What First said, no smell ever and I do haul a Lance and a boat.

[ 03-16-2003: Message edited by: NWDmax ]</p>

[mdrag]

The only time I noticed the smell of diff lube was when I had 'weeping' from the seals - the dealer told me this is normal when I had it checked...

I'd suggest:

1) Check the vent hose from the differential, it snakes up to near the fuel filler opening. Make sure there are no kninks and it slopes upward without dips.

2) Take off the rear tires and make sure the seals aren't leaking.

Good luck.

[Seattle Steve]

GMC- Is what you're smelling possibly hot engine oil rather than gear lube? There is an engine breather tube that dumps under the engine and will leave deposits on the skid plate and other under truck parts. I have that smell from time to time and thought I had a problem... until I read about this in a post on TDP. Good luck!

[GMC D-Max]

Thanks for the help, guys! I'll look into the possibility of crankcase blow-by before I get too concerned.

[Had2HavDMAX]

GMC D-MAX, just wondering if you are still getting the hot smell which you had posted about. I have noticed the same recently and was at first concerned it was my brakes overheating . Had them checked but now I am pretty sure it is a hot oil smell. I too changed to Amsoil (rear diff.) @ 1,000 miles and I am now at 14,000 miles. I seem to notice it only while towing.

[a64pilot]

Not a very technical test I'll admit, but if you can hold your hand on it for a considerable time it's not too hot. If you can't it is hotter than it should be. BTW this applies to a well broken in rear end as yours should be.
I don't know about Amsoil but the other syn oils I'm familiar have to be really hot before they give off a smell. Maybe Seattle Steve is on to something.

[sdaver]

I had two cracked spindles causing rear end fluid to leak or seap onto the rotors.............when they were good and hot you could really smell it.......no major leaks, the dust shields had some oily places on them.........thought it was axle seals but it was a crack around both spindles under the inner hub bearing.........the drivers side was cracked from 10 oclock all the way around to 7 oclock...........needless to say a new housing was needed............Im just glad the tech took a little time to investigate.....my truck was down for four days.........the dealer did a great job of rushing the housing.........could have been a real mess if the spindle had sheared...........how it Happened? Im not sure but a heavy foot, boost, and fuel would certainly enter into the equation........just glad to be here :D dave

[GMC D-Max]

Hey fellas!
Haven't had the truck into the stealer yet, but I'm still smelling hot lube every now and then. And it does it even on short trips around town. I did notice a slight bit of wetness on the left rear rotor (backside) about a week ago. I've got the truck torn apart right now, doing sound dampening, stereo wiring, airride wiring, and finally getting around to doing the OD lockout and high idle wiring. I'm going to get it in to the stealer as soon as it's back on the road. Especially in light of what sdaver posted!! :eek:

Guess I should lighten up on the loud pedal in level 4 from now on?!?