Looking for tsb #35 01-07-30-042A (DEC 02). This references a
problem with clunking at 2-3 upshift or 3-2 downshift. Anyone have
this and care to share it. Dealer service garage told me they could
not replicate the problem with my vehicle. So I must be be hearing
things?. Maybe if they test drove it for more than .5 miles they would
have heard and felt it. Turns out there's a specific tsb on it.
Information on 2-3 Upshift or 3-2 Downshift Clunk Noise #01-07-30-042B -
Information on 2-3 Upshift or 3-2 Downshift Clunk Noise
2004 and Prior Light Duty Trucks
2003-2004 HUMMER H2
with 4L60E or 4L65E Automatic Transmission (RPOs M30, M32)
This bulletin is being revised to add the 2004 model year. Please discard
Corporate Bulletin Number 01-07-30-042A (Section 07 -
Some vehicles may exhibit a clunk noise that can be heard on a 2-3 upshift
or a 3-2 downshift.
During a 2-3 upshift, the 2-4 band is released and the 3-4 clutch is
applied. The timing of this shift can cause a momentary torque reversal of
the output shaft that results in a clunk noise. This same torque reversal
can also occur on a 3-2 downshift when the 3-4 clutch is released and the
2-4 band applied. This condition may be worse on a 4-wheel drive vehicle due
to the additional tolerances in the transfer case.
This is a normal condition. No repairs should be attempted.
Super, that info is a great help to me. Thanks for sharing it.
Not too happy that there's no remedy for it though. Makes me think I'm
driving my clunker 89 chevy pickup rather than a new tahoe with only
18k on it. I've driven chevy trucks, tahoes and suburbans for over 30
years and I don't recall any new ones making such a sound. Sometimes
you hear after 100k. But what can you do. Just put up with the
annoyance I guess.
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