Drivers side front rhythmic "Thump"

[ScottyBoy]

Could it possibly be a bad steering shaft ?

 

[corvette744]

I have an 05 Yukon XL Denali that is giving me fits. It has a rhythmic thump noise from the drivers side front that happens whether you are accelerating, decelerating, or just coasting. It is a very rhythmic thump thump thump thump, pause, and repeat. It changes with the speed of the vehicle. I have replaced the CV axle and the hub assembly and still have the noise. Tires were checked and rotated last week. Checked lug nut torque, all ok. Any suggestions would be appreciated.

YOu said you rotated the tires-did the noise change locations from front to back.If not then its not tires,if it were me i would have a shop put it on a lift and put in 4wd and narrow it down and not throw more parts at it.

 

[lcguy1]

Swathdiver..I torqued the hub nut to 165 ftlb per spec in my book. So, should not be a problem there. Bolts into the front diff were torqued to 65 ftlb. So, should not be a problem there. All the bolts were tightened to the torque specs I have, I don't have the specs on the caliper and brackets in front of me right now. Hopefully, these should not be the problem.

 

[lcguy1]

Wife is taking it into the dea;er tomorrow. Hopefully it does not hurt too much. I appreciate the responses on here. Nice to know there is some place to go for advice.

Corvette.. no, the noise did not change locations when the tires were rotated.

Scotty.. did not look at the steering shaft. hopefully the dealer will do it.

 

[lcguy1]

Dealer says that the front diff is bad. Needs rebuild. Wants $1200 minimum, with no guarantee. Some forums say this is pretty common on these vehicles. It does have 185K miles, so maybe I was lucky. Has anyone ever used ATP automotive front diffs? Can find them on Amazon the cheapest. $700 cheaper than autozone.

 

[swathdiver]

There's a lot of stuff inside the front differential, did they get more specific? You could probably do it yourself; one fella just posted a detailed "how to" recently here. You'll have to judge of course if it pays for you or someone else to do it, time is money.

 

[lcguy1]

I ended up ordering a rebuilt one. By the time I tried to rebuild one, or had someone else do it, it would be a wash, money wise. The swap looks fairly easy?? Ever done one?

 

[swathdiver]

I ended up ordering a rebuilt one. By the time I tried to rebuild one, or had someone else do it, it would be a wash, money wise. The swap looks fairly easy?? Ever done one?

It's been thirty plus years, however, last week I showed my daughter how to change a seal and we had to remove an axle and look inside the rear differential. Thankfully everything went back together just fine and it is in excellent shape. Never had a front differential like these trucks, new to me but I would only tackle it with more space to work and better health.

 

[KATfishing]

Had my front differential changed by the shop on my 08 Denali. I have an aftermarket ASC warranty that covered it. My shop ordered a used diff with 70K (vehicle had 120K on it at the time) that had a guarantee of 10K miles. It was inspected and all has been good since. We chose this route versus a "rebuild"... I was told that so much of it is self-contained. Happy so far. Good luck!

 

[Nashoba]

Tire or tires were my first guess. A flat spot or separated ply could make a thumping noise/sensation. I have experienced it myself.

I also had a very bad rhythmic vibration one time on a trip from Oklahoma to COS, CO. I stopped several times within fifty miles of COS and looked at the tires and shocks and brakes and everything else I could think of. When we got there, I crawled under the '79 Blazer and finally, out of frustration, grabbed the drive shaft to move myself to another point,,,, and got a "clunk/thunk". It was a loose nut on one of the u-joints. Tightened that one, and drove the truck. No more thunking and vibrating. Checked all the other nuts on the u-joints, and the one loose nut was the only offender. Who would have thought of something so simple as that?