I've had my 2004.5 Silverado D/A LLY now for a month with about 1200 miles. My truck is completely stock.
My problem is or is not.......
Driving down the freeway/city and I slow down (take my foot completely off the gas) for traffic or what ever, then press on the gas there's seems to be a hard shift. Dosen't happen all the time but has done it from day one at different times hot or cold.

Is this normal or is there a problem I should have checked out? Thanks for any suggestions and help!

By the way I've had 2 other diesel trucks (99/02 Dodge), and this Silverado D/A is far superior than the Dodge IMO....

I think you should find another Duramax owner and go for a ride with him or her and see. Your question is a tuff one to answer without driving with you.
mike

At 1200 miles your allison probably still has some learning to do.

It might be play in the driveline. I'm not sure how to expalin
but my 02 does it. Let off the gas for a second or two, than step
on it again (not hard) Engages with a bump. I believe lots
of other people have it. Dealer told me it was a characteristic
of the driveline.



Maybe.........?

Are you slowing down enough that the TC is unlocking? I know that if I let off the peddle, and slow down enough for the TC to unlock, then get back into it, to fast, it will hit fairly hard.

Are you slowing down enough that the TC is unlocking? I know that if I let off the peddle, and slow down enough for the TC to unlock, then get back into it, to fast, it will hit fairly hard.

Not sure what TC is but what you've discribed is pretty much what is happening.

Im taking my truck in today for a poping noise coming from the right side of the dash, will have a talk with them about the "problem". I'll post when I get an answer.

TC=Torque Converter


Run it up to about 60-65 mph. Then let of the peddle and watch the Tach. It will fall slowly as your speed drops. When the TC unlocks the rpm's will drop to 800-900 range and stay there while the truck slows down. If you use the brake it may relock (grade braking).


Mike L's idea to drive another truck would also be a good idea. While your waiting for them to finish yours walk over to sales and go for a test drive. A new truck should still be learning and should shift harder than yours.

Took the truck to the dealership. Here's what the Service Invoice says:

Transmission shifts hard 1-2 shift, test drove Vehicle has no codes and all current module cali. are correct. Did Fast Learn on trans to correct shifts and Taps Cells that control shift so FTNESS or FERMNESS.

MW Type Oper/code K5364 DESC: Reprogram
N Type CC:

Only notice a very slight difference while driving.

What does it all mean, have any of you had this done and what hve you noticed?

Thanks