Burning smell after using 4H/4L in snow?

[starclassic]

Was recently off road in some 1-2' snow, driving around in 4H with ease (grass beneath). Maybe 45 minutes of wheelin' around. On one large hill I needed to switch to 4L to get over, I was 3/4 of the way up and losing traction in 4H. Switched to 4L (still on incline but at a stop, in N). Then gave it gas to get over. Then back to 4H.

Park the car for the night and notice burning smell around the rear axle. Would this be typical after driving 4H for an hour or so? Something to worry about? I'm fairly new to 4x4 so I'd appreciate the insight. Cheers!

 

[mtbtim]

Maybe one of your rear axle seals is failing and gear oil has made it into your brakes. Look for a tell-tale spray of gear oil on the inside of one of your rear wheels. If nothing is apparent, you could further investigate by pulling your rear wheels, taking off the drums and taking a look. If you have ABS, you could also could jack up the rear end, put your trans in neutral, parking brake off, pull the sensors out, and turn the axles while looking at the ABS gear. If you see gear oil lapping up onto the ABS gear, sort of like a water wheel, you know the inner axle seal has failed.

 

[TheDurk]

Well, it is hard to imagine anything related to use of 4wd that would cause something on the REAR axle.

So let's ignore that 4wd idea. In addition to Tim's idea, maybe your bellcranks are stuck and one or both of your wheels has its e-brake stuck on. Next time you drive, check (carefully) to see if either of the rear hubs is extra hot.

Also check along your exhaust system. You may have picked up a branch or other debris while cavorting off-road in the snow and it is slowly frying under there.

 

[Tyler James Inc]

I smelled a "hot" smell while going up a steep incline in the snow this weekend as well- I was thinking maybe the trans was getting hot, myself.
That being said, I didn't know whose trans it was. I had a loaded down '14 4Runner and a '14 Tundra on 35's with a 4x4 quad in the bed in front of me. I can't say it was my rig, but I was under the impression someone's trans was hot. That being said, I was in the EXACT situation as you:
Steep incline, in the snow, 4H for a while, 4L for a minute, then back to 4H.
TBH, it could have been all 3 rigs trans' getting hot [emoji23]


Sent from my iPhone using Tapatalk

 

[starclassic]

Maybe one of your rear axle seals is failing and gear oil has made it into your brakes. Look for a tell-tale spray of gear oil on the inside of one of your rear wheels. If nothing is apparent, you could further investigate by pulling your rear wheels, taking off the drums and taking a look. If you have ABS, you could also could jack up the rear end, put your trans in neutral, parking brake off, pull the sensors out, and turn the axles while looking at the ABS gear. If you see gear oil lapping up onto the ABS gear, sort of like a water wheel, you know the inner axle seal has failed.

Thanks for the insight. I'm going to investigate the rear a little more thoroughly. We're getting snowed in here in Chicago so it could be a little difficult looking for spray underneath the car But I'm on the case with your useful ideas.

Well, it is hard to imagine anything related to use of 4wd that would cause something on the REAR axle.

So let's ignore that 4wd idea. In addition to Tim's idea, maybe your bellcranks are stuck and one or both of your wheels has its e-brake stuck on. Next time you drive, check (carefully) to see if either of the rear hubs is extra hot.

Also check along your exhaust system. You may have picked up a branch or other debris while cavorting off-road in the snow and it is slowly frying under there.

Interesting, I guess I just assumed it was the rear because it smelled stronger back there, need to get under and look more closely now. Performance was optimal and I had no apparent issues, crunches, knocks or other audible issues moving between gears. I'll see what I can find. Thanks for the tips.

 

[OldManKamps]

Thanks for the insight. I'm going to investigate the rear a little more thoroughly. We're getting snowed in here in Chicago so it could be a little difficult looking for spray underneath the car But I'm on the case with your useful ideas.



Interesting, I guess I just assumed it was the rear because it smelled stronger back there, need to get under and look more closely now. Performance was optimal and I had no apparent issues, crunches, knocks or other audible issues moving between gears. I'll see what I can find. Thanks for the tips.

I replaced my coil springs a few weeks back and had to droop the axle so low that it tightened my shoes too much in the rear driver side. So after driving for a while, i could smell them a bit. Popped of the drums and my shoes had been melting!!

 

[tystaco]

Was recently off road in some 1-2' snow, driving around in 4H with ease (grass beneath). Maybe 45 minutes of wheelin' around. On one large hill I needed to switch to 4L to get over, I was 3/4 of the way up and losing traction in 4H. Switched to 4L (still on incline but at a stop, in N). Then gave it gas to get over. Then back to 4H.

Park the car for the night and notice burning smell around the rear axle. Would this be typical after driving 4H for an hour or so? Something to worry about? I'm fairly new to 4x4 so I'd appreciate the insight. Cheers!

I agree that you should certainly investigate things to be sure, but it has been my experience having lived in northern MI most of my life and driving through a lot of snow that anytime you go through a lot of powder and send snow into cavities of your vehicle that don't see much moisture it can wash a lot of old oils out...these hit a muffler or hot engine bay, and you get some odor.

 

[starclassic]

I agree that you should certainly investigate things to be sure, but it has been my experience having lived in northern MI most of my life and driving through a lot of snow that anytime you go through a lot of powder and send snow into cavities of your vehicle that don't see much moisture it can wash a lot of old oils out...these hit a muffler or hot engine bay, and you get some odor.

Ha! Good call. So after looking underneath the car and not seeing anything suspect, I'm thinking you may be on the right track. I'm going to drive it some more and see if the smell returns.

I definitely got in some deeper snow and exposed the underside to moisture it hadn't seen in a while.

 

[tystaco]

Don't tell my wife I may be right, she hates that.

 

[fourfive]

maybe your bellcranks are stuck and one or both of your wheels has its e-brake stuck on. Next time you drive, check (carefully) to see if either of the rear hubs is extra hot.

Is there a way of checking for excessive heat? Ive wondered about this whenever I've adjusted my rear brakes. Also wondering what would be considered "to hot"?

 

[OldManKamps]

Is there a way of checking for excessive heat? Ive wondered about this whenever I've adjusted my rear brakes. Also wondering what would be considered "to hot"?

In my experience, warm like laundry FRESH out of the dryer is considered to be normal. Any hotter than that is too much friction I think.

 

[TheDurk]

In my experience, warm like laundry FRESH out of the dryer is considered to be normal. Any hotter than that is too much friction I think.

That's about right. I've had the sticking bellcrank thing and it was hot enough to burn the skin. That's why I said, 'carefully'. If that's it, and it's smelling, it will be way hotter than the others, which is your best reference.

 

[fourfive]

In my experience, warm like laundry FRESH out of the dryer is considered to be normal. Any hotter than that is too much friction I think.

That's about right. I've had the sticking bellcrank thing and it was hot enough to burn the skin. That's why I said, 'carefully'. If that's it, and it's smelling, it will be way hotter than the others, which is your best reference.

That was helpful thanks. I guess one very general way to test the drums to see if theres too much friction is splashing a little water on the drums, after driving it, to make sure it's not sizzling or steaming off?

 

[SpidermanGeek]

That was helpful thanks. I guess one very general way to test the drums to see if theres too much friction is splashing a little water on the drums, after driving it, to make sure it's not sizzling or steaming off?

The excessive heat will also transfer to your wheels. So instead of trying to touch or test the drum or rotor, first check your wheel's temp by touch starting with the outer most edge and working your way toward the hub. Chances are, it won't be hot enough to burn you unless there's something really wrong.

That should just be stage 1. If there's little to no heat, it doesn't mean there's nothing wrong, but if the wheels (especially if you compare heat levels with your other wheels) are relatively warm or hot, you know that you should definitely investigate further.

That's how I found a sticky front caliper.

 

[TheDurk]

The excessive heat will also transfer to your wheels. So instead of trying to touch or test the drum or rotor, first check your wheel's temp by touch starting with the outer most edge and working your way toward the hub. Chances are, it won't be hot enough to burn you unless there's something really wrong.

That should just be stage 1. If there's little to no heat, it doesn't mean there's nothing wrong, but if the wheels (especially if you compare heat levels with your other wheels) are relatively warm or hot, you know that you should definitely investigate further.

That's how I found a sticky front caliper.

That's what I meant. The center of the wheel was hot enough to burn, and that was with the plastic center trim cap on. Don't overthink this.

 

[OldManKamps]

That was helpful thanks. I guess one very general way to test the drums to see if theres too much friction is splashing a little water on the drums, after driving it, to make sure it's not sizzling or steaming off?

A general way is if you can handle leaving your hand on it, you're probably fine. If you can't touch for more than a second or too, its too hot and you're shoes are too tight! At least, that's how I diagnosed my drum issue. But they were so tight that it was a ***** coming off the clutch and I'd have to power through and "break" the static friction of the shoe.

 

[fourfive]

A general way is if you can handle leaving your hand on it, you're probably fine. If you can't touch for more than a second or too, its too hot and you're shoes are too tight! At least, that's how I diagnosed my drum issue. But they were so tight that it was a ***** coming off the clutch and I'd have to power through and "break" the static friction of the shoe.

I actually just tested this when I got home from work which was about a 30 mile drive. Soon as I shut the engine off, I went to the rear drum and was able to place a few finger tips on the drum for several seconds before it started to feel uncomfortably hot.

Was just curious about this because I bought a rear drum caliper to adjust the rear brakes per FSM guidelines & following the FSM verbatim of .5mm shoe to drum clearance, it seemed like it made the rear brakes too tight.

 

[starclassic]

I guess one very general way to test the drums to see if theres too much friction is splashing a little water on the drums, after driving it, to make sure it's not sizzling or steaming off?

I'm thinking you could also take a cold wet rag and touch the drum, listening for sizzle?

 

[fourfive]

I'm thinking you could also take a cold wet rag and touch the drum, listening for sizzle?

I was initially under the impression that it would be hot enough to burn your skin under normal conditions from the friction which is why I was wondering how to check the "hotness" of the drum. Regardless, would be wise to approach it like anything else you might suspect to be hot before touching it with your bare hand.

 

[alumarine]

If the rear shoes are rubbing and causing the drums to heat up that heat will be transferred to the wheels/rim.

You can just touch the wheel near the center to see how hot they are.