Hey guys, first off, great forum. I recently bought a 2001 crew cab long bed with 254k miles. When i looked it over, it needed a driveshaft support bearing. Once i replaced it i noticed a slight humming/vibration kind of like what you would hear from a rear bearing in a front wheel drive car. It only happens between 50-65mph, and it gets louder when you hit bumps. I have crawled under it and found the ujoints to be tight, the carrier bearing to be tight, pinion to be tight. At the transfer case i can push the yoke up about a 1/4" and there is a slight clunk inside the case. I have looked and looked for an answer online and cant really find a good answer. kind of sounds like output shaft bearing, but i have seen a few things saying bushing, can anyone shed any light on the situation?
Vibration/Noise coming from under truck
- Thread starter equipmenthauler
- Start date
Did you check the U joints with the drive shaft out? If not, you need to. Just because they are tight doesn't mean they aren't seizing up.
I will check them in the morning, I am pulling driveshaft and transfer case and doing the pump rub fix. I was just curious to see if anyone had encountered the same issue. I had a drive line shop install the carrier bearing and told him to go though all the u joints then and replace as needed, that was about 2months/3k miles ago.
Ok, so I pulled the case today and broke it down for the pump rub fix, I didnt notice anything to horribly wrong, slight bit of play in the rear output shaft bearing, and a little wear on the bushing, so I will replace those. One thing i was wondering, with the case all broke down, the shaft is loose and will wiggle around in the front imput bearing, is this normal while the case is broke in half?
I tore my case down not long ago to do a pump rub fix and total rebuild, with the case split in half you do have some play in the shaft being all the support relies on the output bearing and mode fork when the case is locked together with the snap ring installed correctly. The bearing can be tough to get out of their seats but with a little time and patience can be done easily, mine was doing a similar noise and was from a stretched chain and worn shift fork, Teflon completely gone, check the shift and mode fork for wear as they may be completely worn due to those many miles, if you need more help feel free to pm me your number and I can assist with pics of what I was looking at that may be able to help you figure it out.:thumb:
Well, after about a week i finally got everything back together. Big thanks to BobbyBDirtyMax for all the help, couldnt have done it with out you. I tore down my transfer case and replaced the rear output shaft bearing, bushing, and seal. While i was in there i did the pump rub kit and did it just in time too, it looked like it had started cutting in to the casing about 1/8". I also replaced all the u joints. well got it all back together and found the real cause of the problem. a few months ago when i had the carrier bearing replaced, when i reinstalled the drive shaft, i did not properly line up the 2 piece driveshaft and put it in the wrong splines. this cause it to be off balance. So lesson learned.
