2001 K2500 intermittent front end shaking

Tyrboss01 · October 11, 2020

My best friend has a 2001 Chevy 2500 4x4 that he uses to tow his horse trailer. He has an intermittent front end shake at all different speeds and different roads. He's not real mechanically inclined and usually has me work on his truck for him. I'm really at a loss cause the issue is so intermittent and random. Because of this I've ruled out tires, hubs, and shocks cause these would be more consistent. I've been researching alot of the questions on this and other forums but most are for a constant vibration not an intermittent one. I have seen some suggestions that it could be the 4wd system trying to engage the front end?? Also read that it may be the transfer case?? But honestly havent really seen much for a very random intermittent violent shaking that happens at all different speeds, sometimes towing the trailer and other times without the trailer. Has happened on city streets, freeways, back roads etc. Usually just slow down or pull over and stop and the issue goes away. He is the original owner, truck is completely stock, has 155,000 miles, just replaced the ABS module and front tire rod ends. Has brand new tires that were just balanced and alignment. Anything else let me know and any suggestions will be greatly appreciated!! Thank you.....

Formulabruce · October 11, 2020

Just dealt with this on a '04 model 2500HD . Since I wasn't sure, I changed the T case fluid and added some motorkote to it. Looked for a wear spot in the housing as well. That did NOT fix it. Off to the front, Not the hubs as I just did them, and the brakes were fine. I took off the skid plate ( this truck has them all) And then drained the front axle housing. The oil was ugly and very dirty, and low. Probably original. Was hard to tell if it leaked due to so much leakage from the stock oil cooler or heater lines that always leak. Changed that fluid with 75w-90 and added 2 ounces of motorkote to it.

Tried all sorts of situations and could NOT get the vibration to come back. 60 miles. 152K on this truck.

Seems like The front diff carrier bearings were shuddering, but thats a guess.

Looks like success.