Summett

Hello,

Your input here is appreciated.

I have a 2004 tahoe (7ok) and have noticed on occasion that when the transmission shifts from 2nd to 3rd (around 25 or 30 mph) there is a slight "clunk" noise. It doesn't happen all the time, and it seems when i'm accelerating easy (babying it) is when it is most noticable to me. When i really hammer the accelerator it is shifting hard (obviously) but i do not hear the "clunk" noise. Maybe at that point that the engine rev is just to high for me to hear it, thus i hear it better when i'm easier on acceleration.

I seem to hear it in the rear end mostly. I took it into have it looked at and the place told me that this is "normal" with these vehicles/trannies and they greased the U-joints, but that didn't do anything.

Any suggestions as to what it might be? It just doesn't seem normal to me not to have a smooth shift between gears. If it shifted hard (with no noise) i would suspect a sensor or something, but this seems like a metal to metal "solid" type sound.

Thanks again for your input.

Mark

jasonw75

It could be the rear diff. I had an 02 and an 00 and I had to replace the rear axle on both of them b4 80K.

Jason

Summett

What did that cost you...if you don't mind me asking?

jasonw75

I want to say it was around $1,200.00. My memory kinda sucks tho. I also don't think this was a great deal. The name of the place that did it was Hy-Way Tire, we call it Hy-way robbery. You might be able to find one at a junk yard, although I believe this is a fairly common problem. You might want to go new. This is a fairly good forum, hopefully someone else will chime in their opinion as well.

Summett

Thanks Jason...any one else have any ideas?

ZX1100F1

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.

Summett

Thanks ZX1100F1! Just not use to it i guess. That...and when you hear something like that...your tuned to it and i find myself listening for it.

Appreciate your input!

unek_one

I have the same problem excpet I have a 99 with autotrac 4x4. Im shifting hard from 1st to 2nd also when i out it in drive and reverse. They funny thing it doesnt do it all the time. One day hard shifting the next runs great. I had the rear diff replaced by the dealer in 04. It was a rebuilt. Started shifting hard 3 years to the date. Any ideas? SOme one told me just might be the filter. Now the rear diff is leaking also.

shnormo

Last time I saw one of those, it was a bad u-joint strap.