I have been having this problem off and on for a month now. I am driving down the highway and all of a sudden my truck starts to shake so violently that I have to pull over and stop. Sometimes it will go away after stopping and sometimes not. At 1st it always started to shake on the highway, but as time went on, it would shake at most any speed. Took it to a mechanic, they test drove it and it did not do it for him. Next day it happened again, took it back and we took a drive to see if it would happen again. It did thankfully. He said it could be almost anything in the drive train. He did one thing to verify something. He put it into 4x4 and it sounded really harsh. He then took it out but it did not disengage from 4x4. He had to stop and back-up 15 feet or so until it made a cluck and disengaged. Took it back to the shop and he drained the fluid from the rear differential and transfer case. Rear diff looked good but the oil in the transfer case was black. Said the transfer case needed replaced. Thet replaced it. Took it home and now I have a high pitched sound when accelerating around 40 mph or so and above. Also the shaking returned as it was before. I did the same thing as he did and put it into 4x4 adn drove it and it sounded like crap. took it out of 4x4 and it would not disengage again. Hd to back up 15 feet or so to disengage the 4x4.

Just asking if anyone has any ideas as to what the problem might be. Truck is worthless the way it is right now. Any help would be muchly appreciated.

Thanks,

 

Pretty common problem in the 04's was the emergency brake(s) sticking. Happened to mine. The levers that actuate the brake in the drum get rusted and can hang up, leaving the e-brake shoes engaging the drum slightly. Get up to highway speed and heat does its thing and the whole truck seems like it's shaking apart. Another problem is the brake cable gets hung up in the hole that goes through the backing plate...check that out too. Some people have enlarged the hole for more clearance and eliminated that problem.

Pull the rotor/drum assembly and see if the levers are rusted up. They can be removed and cleaned up easily, a bit of grease on the pivot doesn't hurt either. I think the newer trucks have a plating on the levers to prevent rusting. I know this has been discussed here before, way back when I had my truck, so maybe searching for "e-brake" can yield some results.

Good luck!

 

What you're describing is called 'Death Wobble' in the 4X4 world. I had it in a Cherokee once and it took a long time to solve. Turned out that the local oil change joint had been putting way too much pressure in the tires, which subsequently were ruined by having multiple belt separations and getting 'lumpy'. I'd hit a bump at 55 MPH and it would start shaking bad. I had everything checked many times and replaced the steering stabilizer twice but it still happened. Finally I replaced the tires, and it was like a new truck. When I sold it I had no qualms about 'selling a lemon' because it was running fine, and the new owner is still enjoying it today.
I'd have to say that this problem is most often related to the wheels and tires. I believe you may have other issues with your transfer case or 4WD. Whatever can be wrong with wheels or tires can cause this, so you can't rule out anything. Balance, alignment, bent wheels, bad tires are the places I would look first, along with the rear brakes as stated above. The tires might look fine and balance fine but can still be bad. I had every kind of balancing done that you can get and it made little or no difference. You may be able to see out of round tires with the wheel chucked up in the balancer and rotated slowly. This will also quickly show bent or out of round rims.

 

This happened to me too. I can't say for sure it was the e-brake but after an adjustment to the e-brake it never happened again. '05 4X4

Also, I'm not sure if this was related but the rear rotor/drums were insanely stuck on when I went to pull them off (a couple years later). Might want to borrow a large puller or at least know where you can get one if you don't have one......and yes I had completly unhooked the e-brake so it wasn't hanging up the rotor.

 

My bet is on the e-brake as well.