BAD (and I do mean BAD) VIBRATION

[GMCYukalade]

ya, i didn't really know what mine was doing at all - all of a sudden it just started making a noise - when i jacked it up i could actually see the broken cups - but i couldn't move the drive shaft at all

 

[Sejo]

How much are these U-joints/cups costing you guys and where are you getting them? Any special discount places?

I think I'm starting to have the same problem. Could this problem arise from over or under tightening? Just had some transmission work done and it only started vibrating recently. What are the torque specs for reinstalling the driveshaft?

 

[SPXTrader]

About 5 bucks per joint at NAPA. Not too sure what the GM part costs. The cups (also called caps) are part of the u-joint.

Just had tranny work done and now a vibration, eh? Possible drive shaft index issue. Take it back to the shop and ask if they indexed the drive shaft properly when they re-installed it. Tell then it's vibrating now, where it wasn't before they dropped the DS, IF this is a true statement.

 

[Sejo]

About 5 bucks per joint at NAPA. Not too sure what the GM part costs. The cups (also called caps) are part of the u-joint.

Just had tranny work done and now a vibration, eh? Possible drive shaft index issue. Take it back to the shop and ask if they indexed the drive shaft properly when they re-installed it. Tell then it's vibrating now, where it wasn't before they dropped the DS, IF this is a true statement.

So I just need to ask for the U-joint caps/cups; those are $5? Not the U-joint itself right?

I know it's something the Tranny Shop did, I'm already not really happy with their work so I'm a little weary about taking it back there for anything.

What all is involved with Driveshaft indexing?

 

[SPXTrader]

So I just need to ask for the U-joint caps/cups; those are $5? Not the U-joint itself right?

I know it's something the Tranny Shop did, I'm already not really happy with their work so I'm a little weary about taking it back there for anything.

What all is involved with Driveshaft indexing?

The u-joints are a complete assembly. They come with the caps/cups.

When you had your tranny rebuilt, they had to drop the DS in order to remove it. From the factory, the DS itself is balanced. When installed, the whole drive line is then balanced, and index marks are made to note the proper placement of the DS to the yokes. These marks are on the yokes of the DS (both ends), output shaft, and rear end. When replacing the DS, you need to make sure these marks line up, or you may experience a vibration.

I'd take it back, tell them your problem and ask if the index marks were lined up when they re-installed the DS.

 

[CRXMotorsports]

Hey SPXTrader (or anyone for that matter).

97 Yukon here, RWD, 157k miles... I have this incredible shudder throughout the entire truck, comes on in the 65-70mph range. Reading through this thread and a couple other Chevy truck threads, I'm thinking the $25 for a greasable, (supposedly supertough) U-joint makes sense to do. I'm sure it hasn't been replaced on this beast.

My question simply is this: Would a bad U-Joint made the truck shudder, and would it be consistant with a bad u-joint for the truck to shudder MUCH worse under a load, trailering approximately 4000lbs?

I notice a small vibration/shudder thoughout the truck at those speeds, but it becomes extremely pronounced and bothersome while towing the race car. In a 2WD Yuk, is there just 1 U-Joint on the driveshaft (yet to crawl under it to look)? Or are there multiple ones on it? one on each end, etc.

After this it is time for tie-rod ends and a fresh alignment, I replaced the pitman & idler arms, which helped a great deal for my previous steering issue, but this vibration is getting crazy and annoying.

Last bit of info: Only modifications to the truck is a power programmer, not lifted or lowered, new shocks all 4 corners, and air bags on the rear (just to help with towing, normally kept at 10-15lbs which is the minimum)

 

[blk87brd]

Bad u-joints could well be the problem, however, they are usually accompanied by clunks and thumps when increasing or decreasing load on them. And, yes there are two. Without anything other than the description you have provided, my guess is you are looking at a transmission mount issue. I had a bad vibration in a pickup once, the mount looked okay. How I found it was by taking a racket strap around the tail shaft housing and to the cross member, tightening it up and going for a drive with the trailer attached. No vebration, (well, gratly reduced). Changed the mount and that was the end of the vibration.

 

[CRXMotorsports]

No problem at all, I can easily do that while I'm under the truck, my thought process is that at over 11yrs. old, 157k miles, and most of it towing, the U-Joints are worth replacing regardless. The truck has clunks and thuds from a dead stop. The transmission was just rebuilt/replaced by a reputable shop within the last 10k miles, I am unsure if mounts were included in that. I may just do the U-Joints, see what I get, and put trans mounts on the list of 'next to do'.

 

[telmd]

97 tahoe here with 187k. Noticed a vibration at highway speeds. Checked the tires once i stopped and noticed that two of them were warped/bubbled causing the vibration so you may check those....

 

[CRXMotorsports]

Well, UJoints replaced, no better, still a bad shutter under towing (more noticable while towing anyway).

All steering components, tierod ends, sleeves, idler arm, pitman arm and alignment are done. I am at my wits end about. I am going tonight to have the wheels double-checked for balancing... The truck still gets a terrible shutter at 65-70mph, below that it is fine, above that it remains. I feel I'm running out of replacement items here!

Brakes are still crazy and terrible too (but that's discussed by many in plenty of other threads!)

 

[Sejo]

Well, UJoints replaced, no better, still a bad shutter under towing (more noticable while towing anyway).

All steering components, tierod ends, sleeves, idler arm, pitman arm and alignment are done. I am at my wits end about. I am going tonight to have the wheels double-checked for balancing... The truck still gets a terrible shutter at 65-70mph, below that it is fine, above that it remains. I feel I'm running out of replacement items here!

Brakes are still crazy and terrible too (but that's discussed by many in plenty of other threads!)

I'm still getting a bit of vibration too. I'm starting to wonder if it's something in the tranny itself (Torque Converter), Oxygen Sensors, the intakes MAF (Mass Flow Sensor), maybe the throttle body is shot or needs good cleaning?

It just seems like it could be that the engine is sucking in bad air or not enough air.....? Just some thoughts.

The vibration comes and goes for me, sometimes it really bad to the point that I'm ready to burn the thing to the ground and at other times it's running great. Sometimes I think it gets worse towards the tail end of needing an oil change.

It irritates me either way.

 

[PotentialTahoe]

i, but the suburban has electronic shifters, i think they stopped the mechnical shifters in the early 90's like 92, but whats funny is the 06 silverado base model has mechnical shifter encless you paid 500 to get electrionic. so NOPE i have never seen a 99 with mechnical shifters. sorry. but why do you ask??

I have a 99 Tahoe with floor shiftr 4x4.

 

[Mcm1209]

I know i know
OLD ASS THREAD Revival
But everywhere i look i cant find an answer. I have this bad vibration about 68 mph and up, passenger seat, dash steering wheel, the whole interior you can see a shake.
New wheels and tires.(will be going back to check balance)
New front end steering components. (All of them)
Good alignment
New shocks front and back
New u joints
If i let go of the gas its still there.
Before 68 mph its so smooth!!!!!
Ill be changing out the motor and trans mounts here soon
Tahoe does have 240k miles on her
I guess I need to be thinking of rebuilding the rear end?
It is not noisy or anything like that.
Just wanted to get this thread going again because it is the one with the most scenerios

 

[js20072500hd]

I have a 2007 Silverado classic 2500hd 4x4 extra cab... had remanufactured tranny put in at 125000 miles. ran smooth before, now I have the same vibration. smooth till 68-69 mph vibration between 70-80mph. after 80 smooth's out mostly. varies a little with gas pedal use.. lets of a little when I let off the gas but as long as I'm pressing on the gas pedal it is there. Driving me insane. anyone figure out the issue? new u joints new tires and drive shaft looks perfect!???????

 

[lesterl]

Try the 2001+ forum.... this is 1994-99..... I have some vibrations as well, but am going to try new Ujoints myself....