2005 Safari AWD, shudder/vibration at 55-65mph

[mannygmt2]

Hi all
I have a 2005 Safari Cargo AWD that i use for work. I am the only one that drives the van, and its basically my service truck.


I noticed a few months ago, that when i drive at 55mph... i get this shuddering/vibration noise that i feel is comming from the back of the van

The car does not shake or anything, there is a humming kind of noise. Over 65mph... it dissappears. Between 55-65...its very annoying. If i let go of the throttle between 55-65mph... the noise is gone... so i guess when the tranny is under stress ...the noise comes back.

I went to a truck tranny specialist, they looked at the driveline and said it was fine, and they were not able to locate the problem

I went to GM last week, they changed my passenger side bearing/hub (??? ) and that obviously did not resolve the problem (more like a dent in my wallet). The van is back at GM right now, and they are still looking into it, they think its an internal problem of the tranny.

My van has only 43K miles, its a 2005, so its out of warranty

any ideas?

[cyclone]

i agree with GM it probably was internal problem of the tranny.

[shadams]

See what you think of this:

00-03-09-001B: Rolling Boom Noise Inside Vehicle (Install Pinion Nose Damper and/or New Rear Leaf Spring Dampers) - (Oct 19, 2004)


Subject: Rolling Boom Noise Inside Vehicle (Install Pinion Nose Damper and/or New Rear Leaf Spring Dampers)


Models: 1995-2005 Chevrolet Astro Van Models

1995-2005 GMC Safari Van Models




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This bulletin is being revised to add the 2005 model year, change a nut part number within the spring damper kit and change a quantity in the Parts Information. Please discard Corporate Bulletin Number 00-03-09-001A (Section 03 - Suspension).


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Condition
Some owners may comment about a "boom" noise inside the vehicle while driving at speeds ranging between 97-105 km/h (60-65 mph). This condition is most noticeable from behind the driver's seat.

Cause
The condition may result from an engine-firing harmonic, which becomes noticeable at torque converter clutch (TCC) lock-up.

Correction
A new rear leaf spring damper kit (containing two dampers , one per spring) has been developed, to be used in conjunction with a pinion nose damper tuned to 86 Hertz (Hz), to reduce the resultant noise level.

AFFECTED VEHICLES MAY REQUIRE THE INSTALLATION OF THE PINION NOSE DAMPER, THE SPRING DAMPERS, OR BOTH. THE INSTALLATION OF EITHER OF THESE DAMPERS IS AT THE DISCRETION OF THE TECHNICIAN FOR BEST RESULTS. Use the following procedures and the appropriate part number listed below.

Important: Installation of these dampers will not totally eliminate the boom noise. The boom noise may only be reduced to a more acceptable level. There may be other boom noises, such as body or exhaust, associated with the vehicle and this fix may either diminish or enhance the noise. These other noises should be addressed prior to the correction for the TCC boom dampener being installed.