Accidently drove too long on pavement pulling a trailer in 4-wheel drive All drivetrain components (axle, both differentials) began to smoke to my horror, & I immediately pulled over. But must be some damage because I hear a clicking sound up front. I know I have to change differential oil, but what do you think I damaged to have that clicking sound: U-joints, bearing, etc. ANY help would sure be appreciated. I REALLY screwed up. Worrying about the trailer I was pulling & forgot to change back to 2 wheel drive. Probably drove 50 miles, ot sure. HELP! Please…
Make, model, year, mileage?
Do not know the car yet, now I made the mistake, maybe 50k miles ago of leaving my trailblazer in 4 lo and taking off on the highway. It was acting weird pulled over and realized what I had done. No smoke, thee car was not happy at the time, but all is well that ends well. If I had to guess you may have busted some bearings in the transaxle, but as stated previously make and model are important .
Does it sound like it is coming from the front wheel area? On my free running hub Ford 4wd truck, the hubs are the things that start to complain if I do this. One time I had one where the parts just sort of popped out of their nominal position and just removing, lubing, and reassembling the hub parts fixed the noise.
Know this is Ford forum, but vehicle is 1999 Tahoe 
sound is beneath firewall.Almost sounds like fan hitting shroud, but of course that’s not problem.
Is the truck now home or somewhere on the road? And for sure knowing make, model and year would be helpful. And how ‘hands on’ are you with maintenance?
That sounds like a more expensive than the hubs. Best outcome would probably be where the axel connects to the front differential. It splines in, and those splines may just need a little cleaning up.
I was driving to Yellowstone one time and had this happen in a rear drive car. It made a ticking noise. The shop pulled the two rear axels and cleaned up the splines and it fixed the noise. That was a Ford too though, a 2wd car.
I can’t see any reason for smoking gear-boxes unless the tire sizes are very mismatched…People do this all the time without any drama, just reduced fuel mileage and accelerated tire wear…
For the record, this isn’t a Ford forum. Just a car forum.
The smoking bothers me, but in general this vehicle does not use a solid front axle, it uses a differential with half-shafts very much like a FWD car, with a tripod plunging joint inside and a rzeppa joint outside. Unless there’s a limited slip differential in the middle, I cannot envision a possible reason to overheat. Even then I wouldn’t think it should, but I’m thinking wildly at the moment.
How heavy was the load?
Under what conditions does the clicking occur? Is it in time with the wheels or the engine?
Open thinking here: perhaps the front CV joints aren’t designed to stand up to sustained loads of the type you’d experience trailering a heavy load on pavement.
I’m stuck, and just throwing thoughts up on the air. Perhaps someone more knowledgeable of this system will take an idea from one of these thoughts.
I hear y’all and many thanks. Was pulling a Mazda 626 on a 2 wheel car dolly & lots of hills. Smoke was coming out like a 5 alarm fire. Diff. was smoking, as well as whole axle, and transfer case. I was scared spitless.Made it home after letting it cool down & putting in 2 wheel drive and going very slow. On the way home occasionally heard the noise-a little louder at times & then it would go away. Next morning made the ticking sound as soon as I started moving. Sometimes noise would stop, then start again. I am stumped too. Will put it in the air tomorrow & take a look, but relly worried tonight.
\Again–THANK YOU guys & I’m still thinking. Probably no sleep tonight…