Sorry to repost from Emergency thread, but

I towed about 6K in 4WD for about 25-30 miles in 4wd (4H)

noticed pulling a long steep hill

Smelled like brake smoke, smoke coming out from under truck, brakes cool

Took it out of 4WD, waited a few minutes, continued driving for another
30+ miles...

Initially was going up hill on freeway 55-60mph

still smelled faintly when I got home...

What kind of damage did I do? What do I do now? want to haul today..

 

My guess is you either left the park brake on or partially on, or the clutch was slipping. If the truck has a limited slip differential (posi) and the roads were dry then the clutch pack in the diff could now be fried. If the tires are all the same size and worn the same and the road had no tight turns then you should be ok. Lots of "IF's" I sometimes use 4X4 while pulling my 12500lb 5ver while descending in the mountains but my truck doesn't have posi.

 

The parking brake was definatly released

It a 5 speed, and I think it has posi (LSD)

Clutch seemed to work fine all the way home...

Hate to trailer with it today and have a problem...

Guess I'll have the shop take a look...thanks Jenni

 

Unless you were doing a lot of tight turning, I wouldn't think you've done much harm.

If the brakes were cool and smoke was coming from underneath the truck I would suspect clutch.

Shoot, I drag race with my truck in 4wheel drive at over 100 mph, going in a straight line of course.

 

Yep I would suspect clutch. Clutch and brakes smell very similar.

 

X2 on this one, plus i have driven mine for about 100 miles in 4hi on accident once... you should be ok.

 

Yep. You won't hurt it driving in 4WD. That just causes more tire wear and more drag. More load on the drivetrain, but not a disaster. I can't say what the smoke was but it's not the differential. The clutch sounds like the most logical guess.

John

 

our front axles are always spinning unless you have a hub kit. i wouldn't recommend towing in 4wd but think about it. everything is already spinning freely. the only diff. is in 4wd the t-case is spinning the front diff instead of the front diff spinning the t-case. if you weren't making tight turns on dry pavement you should be fine. as far as the smoke i would think the clutch would be the prob. if it were your brakes you'd feel them dragging.

 

Check your trailer brakes just in case. I the same smell last month and thought that it was my SBC FE, but one of my trailer brakes were grabbing. Hopefully it something easy and not the clutch.

Mike

 

A guy (not a truck kind of guy) I met at work told me he always pulled his travel trailer in 4wd while ascending long steep grades on the freeway at 75+. He had been doing for a few years. I told him to stop that, and he did.

As far as I know it never caused a problem, but his was an automatic.

 

x2 you didn't hurt anything by using 4wd. Everything is already spinning.

 

In the winter mine never comes out of 4 wheel drive and like said above its allready turning your diff so it wont make a bit a difference. I have never had a problem leaving mine in all the time. And if you seen how I drive you would be wondering why my truck is driving down the road let alone all in one piece.

 

Big difference between "already spinning" and engaged in 4WD. When it's engaged the front and rear axles have to turn at the same speed but the front axle wants to turn faster in corners, so there is binding and tire slipping.

The system is strong enough to handle it without breaking something but it puts a heavy load on the whole drivetrain. Saying it OK simply because it's already spinning misses the point and overlooks the heavy stress.

John

 

AFAIK, none of our trucks came with limited-slip front differentials, so that source can be eliminated.

The 3rd Gens have AAM differentials that are available with a Torsen gear-type limited-slip for the rear end, so there aren't any typical "consumables" to wear out.

The 2nd Gens, however, came with Dana differentials that had clutch-type limited slips available; if for some reason there is a significant difference in diameter between the left & right rear tires, and you drive it for a while like that (especially at higher speeds)....


You'll cause Expensive Smoke to be released from the differential! Don't ask how I found out...

 

I understand that but the only way you have any binding is doing tight turns on pavement. I doubt you do many "lock to lock" turns TOWING at 55 or 60mph as the original post stated. It's a truck not a newborn baby, if the drivetrain can't handle the slight bind of a 4wd turn then maybe Dodge should use parts that can.