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Burning Smell After Use Of 4-Hi

Chief

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Edmonds, WA
OK, I've noticed this several times and I chalked it up to break-in but it still happening.

When the pass conditions are bad (and lately they have been as bad as January) I'll use Auto 4WD, and when things become completely snow covered, switch to 4-Hi going through Stevens. The entire trip between Auto and 4-Hi is roughly 20 to 30 miles depending on conditions. The uphill route is done with the engine under load due to the grade and I'll usually down shift to third to keep the transmission from hunting between OD and 3rd gear in the flatter parts of the switchbacks.

When I get out of truck after crossing the pass (or stopping to ski) I'll notice a burning smell. It seems to be coming from off of the exhaust system as it is stronger on the passenger side. I've stuck my face down in the wheel wells to make sure I'm not dragging a stuck caliper (read about that issue) and it's not brakes. When driving there is no binding of gears, hum, noise, or strange behavior. I'm not going over 45 MPH when I'm using Auto 4WD or 4-Hi (following the flow of the traffic). Usually when I hit the sheet of ice they call a parking lot at Stevens I'll use 4-Hi there.

I don't notice this smell when I drive around day to day in 2-Hi. The smell is not entering the cabin but is strong outside the vehicle at the rear, and strongest on the exhuast side. No carbon deposits on the cladding, and no oil smoke from the exhaust. Thoughts on what this might be (vehicle info is in sig file below)...
 
I'm just guessing, but do you think maybe your transmission is getting a little hot going up the hill in 4WD? ?It seems the computer would have caught this though. ?Obviously something is getting hot. ?I would check your tranny fluid and the front differential. ? ???

Have you noticed anything smoking or dripping on the exhaust. ?Such as oil, differential, or tranny fluid? Also, it the only time you notice the problem. (Going up that hill)?
 
Can you define the smell a bit more?

Ie burning oil or.... ?

Maybe it is something hitting the Exhaust while on this road.

try driving in 4WD on another road and see if it happens. preferably a flat normal road.
 
Nope - not burning oil, trans fluid, rubber, etc. I guess the best analogy I can use is back in the old days when you would get your car under coated, and that coating would burn off of the exhuast system. It smells more like that...
 
Check the front axle housing vent tube for possible gear oil discharge. Do the same thing for the transfer case.
Make sure the tubes are not kinked, damaged or improperly installed.

Check the fluid levels in both gear boxs.

With the fluid inspection plugs removed, check for burnt
smell in the fluids.

Hope this helps.

FP
 
This may sound stupid, but it really sounds like the ice and slush build up under and on the side hitting the exhaust system and boiling off.
 
In Buffalo when it snows you get a lot of snow and ice under the vehicle. I smell this a lot when I have the Av running a lot and I am going throught wet or heavy snow. It smells like something is burning. The only thing I notice is that the muffler is real hot and steam is comming off it. All the trucks I have owned have had that smell at one time or another. Hope this helps
 
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