2007 Sierra- clanking when shifting

[elky78]

I purchased a U7194 (Revision 9R05) Predator last week and loaded the 87 octane tune onto my 5.3L 2007 GMC Sierra (36,000 miles). I was really happy with it, but I am currently having trouble with my truck clanking when I shift into drive or reverse.

It was so bad when shifting into reverse today that I thought I had backed into something.The only parameter that I changed was to disable the DOD. I went ahead and restored the factory tune, and the problem seems to have went away. My truck also seems to start harder when the 87 tune is loaded.

Any help is appreciated. Thanks.

[CANUCKPREDATOR]

don't think its tune related, since there is NO tranny adjuTCM support on the NBS trucks

any codes?

[pawngod]

i would check your u-joints...they make a clack when worn

[06MonteSS]

could be cuz the tunes disable TM from the engine side, so there is more torque being delivered to the tranny??

[elky78]

Thanks for the replies. I had time this weekend to check out the drivetrain. I found that all the nuts on the transmission mount were loose.

Thanks again.

[WhiteBuffalo]

Thanks for the replies. I had time this weekend to check out the drivetrain. I found that all the nuts on the transmission mount were loose.

Thanks again.

Interesting!

Time to climb under the Av again....

[06MonteSS]

Thanks for the replies. I had time this weekend to check out the drivetrain. I found that all the nuts on the transmission mount were loose.

Thanks again.

D'OH!!

wow, good catch...