[JCMeltz]

Hello
I have a 2003 Chevy Suburban 2500 4x4 with 8.1lt engine .411 gearing, 110k miles. I have owned this truck for a while and have always had a little shake on the highway and at varying speeds over the years. It bothers me.

I just put new Nankang tires I got cheap from Walmart on and it's shaking more than my old, worn out Yokahama. I also powder coated the rims black, but I'm not sure if that is the problem or not. I have had it balanced twice and the last time it was one of the modern high speed balance machine only some tire places have. The balancer said I needed to change my steering arms and bushings. My mechanic said no. Wondering if I just bought bad tires or the newly powder coated, old custom 20" rims could be the problem??

I like the truck and the 454 engine, but I would like it to drive better on the highway. Up to 50 mph everything is fine, at 65 the cab, passenger seat and even a drink in the cup holder start shaking. The steering is a little lose but not bad for an old truck. No excessive shake in the steering wheel. Any suggestions will be appreciated.

 

[bazar01]

Looks like the same issue I had with my 2001 5.3L suburban.

 

[bazar01]

Mine had no steering wheel shake but the whole body shook like crazy. I can see the seat head rests shaking sideways.
Usually this is a driveline issue.
Mine turned out to be a loose transmission mount bolts hidden underneath the cross member.
It caused the tail end of the transmission to shake.
I found the problem after spending on u-joints and installing new tires.

Yours could be a little more complicated to diagnose since it has two drive shafts.

 

[blackburb]

Well, you don't have 454 engine or 4:11 gears. It's a 496 and 4:10. Check the U-joints. If tires/wheels are properly balanced, that's usually the next culprit.

And if you do change U-joints, don't do like I did and forget to mark the yoke and end up putting it on 180 degrees out.

 

[djosh611]

I've also had this problem and turned out to be tie rod ends. But I would also check U joints

 

[Paladin]

You may also want to check the drive shaft. A slightly bent drive shaft can cause vibration.

 

[JCMeltz]

Thanks for the input. I will look into U joints and hope that's the problem.

I was told if it was the drive shaft, it would shake all the time. My shake varies and is bad at 65mph, but smooth's out above that???

 

[JackE]

So, I have seen mentioned in a few different posts to mark the driveline on these newer units so you don't get them in wrong. When did this become a thing? I have been out of the garage scene since 2001 and haven't owned one of these newer than my '99, so I'm in the dark on this. I have never had an issue with just sliding the shaft in however it would go in. If it was required to go a certain way, there was a keyway in the output shaft that matched the splines on the yoke. If it's so important to line it up exact, why didn't they use the keyway set up?

 

[bazar01]

To me what mattered most was marking the relative positions when disassembling the front yoke from the main aluminum drive shaft when replacing u-joints.
This is because the whole drive shaft assembly was balanced as one piece.
The yoke position relative to the transmission output did not matter to me as well as the differential end.
My 2001 Suburban is still so smooth.

 

[JackE]

Ok, I'm following now. You're talking multiple piece drivelines. I wasn't thinking that direction because all my Suburbans have been one piece. Yes, I have always marked the slip joint on two piece drivelines.

 

[kennyb79]

well wait a minute...if its shaking worse now, and you just put the tires and wheels on it, its gotta be the tires and wheels. the shake you had before was probably an unbalanced wheel with the old tires as well...some of those cheaap tires are impossible to balance

 

[geo1]

So you wrote,no excessive shake in steering wheel,but a shake? just trying to see if it's a rear tire,and how much balancing weight is on the rims,when I have had a bad balance problem,I started moving tires,all to front driver side,to feel the worst shake in steering wheel,marked tire,wheel and dismounted tire and spun it on the rim180

 

[JCMeltz]

Good news for me. I went to the local dealer Bomnin Chevy here in Miami to try a second round of Road Force Balancing. Even though I had this done recently, I want to try it again as the mechanic I used before left me feeling uneasy. The dealer said 3 of the tires were completely out of balance. The car drives better now then it ever has. I don't normally go to a dealer for service, but this time a $53 bill solved the problem.

I had a feeling the mechanic sales guy I used before was just trying to sell me on replacing tires rods and a whole bunch of other parts to run up the bill. Shame on you. Thanks to Mike at Bomnin Chevy, my car just needed a honest balancing, nothing else was recommended.

 

[blackburb]

Glad you solved your problem. Now please stop referring to a Suburban as a "car". It's a TRUCK dammit! Hence this thread being on the gmtruckclub forum.