08 Tahoe Vibration - SOLVED

[Fless]

Since this is a 4x4 I would think you could remove the front driveshaft and try it like that, before replacing it. You might get some kind of sensor warning to ignore, since there is likely a speed sensor at the front of the transfer case.

 

[Caveman1975]

I once chased an odd vibration on a 1985 Caprice. It ended up being loose torque Convertor bolts. They were noticeable, and 1 had backed out to just 1 thread holdingit on. Might be worth the time to look into a flywheel/torque convertor issue.

 

[steve45]

You said that a Road Force Balance was done, but this does not replace a standard balance. Have you checked that the tires are round?

 

[B-train]

Buy 2 new u-joints from an autonparts store and do it yourself. Or, take it to a DIFFERENT shop and have them inspect the rear driveshaft and u-joints. I put my money on the pinion one being toast and stiff as a board.

Your GM dealership is pathetic......sorry to say. They milked you for gravy work, much of which doesn't cause a vibration that increases with speed, and doesn't go away once in neutral. For cripes sake......

 

[mikeseay]

Hey Guys,

I have been chasing a vibration with no success that appeared out of no where in my 08 Tahoe LTZ and am coming to more intelligent minds than my own for suggestions/input.

Vehicle Details: 2008 Tahoe LTZ 4x4 with 165k miles (no lights on dash and no codes returned when scanned)

Symptoms:

• Vibration on both acceleration/deceleration (which prior to the first dealership visit was most noticeable above 77mph; it was observed at lower speeds as well ~40/45mph but at 77mph a passenger would identify that there was a vibration)
• Vibration is still present when putting the transmission into neutral at speed.
• Vibration is most noticeable on acceleration (for example; accelerate to 60, let off the gas, and the vibration is less on deceleration than it is upon acceleration).

I took it to the a local Chevrolet dealership for diagnosis and had their suggested work completed on it but the issue seemly is worse/more noticeable at lower speed than it was when I first took it in.

During this first visit to the dealership they:

• Replaced both Front Hub Bearings (technician noted that they were noisy and that the RF had play)
• Replaced A/C Belt (cracked)
• Total A/T Fluid Exchange
• Replaced Front Differential Pinion Seal
• Front Differential Service
• Front Differential Kit Service Synthetic
• Transfer Case Fluid Exchange
• Power Steering Kit Service

After that visit and noticing that the issue still existed, we took the service manager along for a drive on the highway and exhibited the same behavior as noted above. During this trip, it was observed that when power braking the truck that at least one of the engine mounts had failed.

During the second visit they:

• Replaced Both Engine Mounts
• Replaced Exhaust Manifold Gaskets and Bolts
• Replaced Exhaust Seals (2)
• Road Force Balanced All 4 Tires

Obviously a little defeated, I took it home after the second visit and wanted to rule out a tire issue (I believe this could be ruled out as the vibration subsides on deceleration) so I rotated the tires but there was no change in the symptoms after this. I checked for missing weights on both front and rear driveshafts and did not find any indication of any missing.

The truck was 99.9% of the time operated with the 4x4 selector in Auto but since having this vibration was switched to 2HI (and has been since before the first visit) in apt to rule out any complications there but the issue still existed. If I change the dial into Auto, I can hear the some engagement below the vehicle and nothing sounds bound up in the transition or anything.

Hey Guys,

I have been chasing a vibration with no success that appeared out of no where in my 08 Tahoe LTZ and am coming to more intelligent minds than my own for suggestions/input.

Vehicle Details: 2008 Tahoe LTZ 4x4 with 165k miles (no lights on dash and no codes returned when scanned)

Symptoms:

• Vibration on both acceleration/deceleration (which prior to the first dealership visit was most noticeable above 77mph; it was observed at lower speeds as well ~40/45mph but at 77mph a passenger would identify that there was a vibration)
• Vibration is still present when putting the transmission into neutral at speed.
• Vibration is most noticeable on acceleration (for example; accelerate to 60, let off the gas, and the vibration is less on deceleration than it is upon acceleration).

I took it to the a local Chevrolet dealership for diagnosis and had their suggested work completed on it but the issue seemly is worse/more noticeable at lower speed than it was when I first took it in.

During this first visit to the dealership they:

• Replaced both Front Hub Bearings (technician noted that they were noisy and that the RF had play)
• Replaced A/C Belt (cracked)
• Total A/T Fluid Exchange
• Replaced Front Differential Pinion Seal
• Front Differential Service
• Front Differential Kit Service Synthetic
• Transfer Case Fluid Exchange
• Power Steering Kit Service

After that visit and noticing that the issue still existed, we took the service manager along for a drive on the highway and exhibited the same behavior as noted above. During this trip, it was observed that when power braking the truck that at least one of the engine mounts had failed.

During the second visit they:

• Replaced Both Engine Mounts
• Replaced Exhaust Manifold Gaskets and Bolts
• Replaced Exhaust Seals (2)
• Road Force Balanced All 4 Tires

Obviously a little defeated, I took it home after the second visit and wanted to rule out a tire issue (I believe this could be ruled out as the vibration subsides on deceleration) so I rotated the tires but there was no change in the symptoms after this. I checked for missing weights on both front and rear driveshafts and did not find any indication of any missing.

The truck was 99.9% of the time operated with the 4x4 selector in Auto but since having this vibration was switched to 2HI (and has been since before the first visit) in an attempt to rule out any complications there but the issue still existed. If I change the dial into Auto, I can hear the some engagement below the vehicle and nothing sounds bound up in the transition or anything.

It goes without saying that I am nearing my wits end on chasing down after already sinking a substantial amount of money into the fix. This truck has been solid with very little minor issues and shows that GM knew how to crank out quality even after a recession.

The only bad idea is no idea so shoot any ideas that you might have.

Appreciate any and all knowledge and experience for you guys! Thanks in advance!

Have you tried breaking down your wheels and tires? I a previous life I was balancing tires on the old on the car spinner and on a couple of times you could get a nice smooth balance then put on weights and spin it up to recheck the balance and it would be off again. Turns out it had water in the tire cavity. Sometimes when airing the tires up moisture had built up in the compressor and it would blow water in the tire with the air. Doesn’t take much moisture to throw the balance out of wack. Lots of people don’t drain their compressors like they should. Good luck

 

[08TahoeVibes]

Update:

We replaced the front driveshaft with a Doorman replacement this morning and there was no change. The same vibration was still there.

After that, we swapped a different set of wheels and tires to rule those as being a potential issue and the issue persisted.

If we believe that the rear driveshaft/UV joints being the cause here, is there an efficient way to test this theory out in the garage?

 

[donjetman]

is there an efficient way to test this theory out in the garage?

check it for straightness
check for u-joint wear/sloppiness

 

[mikez71]

Learned a lot of tidbits in this thread!

Hope it's your rear driveshaft! (I am surprised it wasn't checked after two visits..)

 

[Geotrash]

I would take it to a shop who can put a set of chassis ears on it, or maybe even buy a set to have in my toolbox. Nothing better for isolating driveline problems.

Otherwise you’ll keep throwing parts at it never knowing if you’re even targeting the actual problem. A driveline shop should be able to do this.

 

[Coveman]

I read your thread and wonder if you could think of anything that happened just before it ‘started out of the blue’ (did anyone else drive it? Was it off-roaded, popped a curb, big ol pothole? Anything you can think of?)

My gmt400 started making a rubbing / vibration as it neared 200k. That turned out to be the tcase shaft rubbing against the case. That got louder and louder as time went on.

On my gmt900 I got a rubbing sound when turning the steering wheel after the oil cooler lines were replaced (the front axle needed to be lowered to replace the lines and the differential had been lowered to get the lines on and it was secured slightly off during the repair; fixed the rub after loosening the differential bolts and realigning)