This is my first post to the forum.


I am a novice, so I have learned a great deal reading all the info posted (not quite up on all of the lingo but am learning).


I have 2002 Duramax Chevy with 28,000 miles that I bought new. Recently, the transmission started to periodically "shudder" when shifting to 5th gear - the whole truck shook when it happened - usually when going up a grade and shifting into 5th gear above 50 mph. I changed the spin on filter, but that did little if any good.


The truck is under warranty, but the small dealer where I purchased the truck does not work on transmissions, so they sent the truck to a GMC approved transmission shop where a shift kit upgrade was installed.


The shifting is much smoother now, but occassionally the shifting does the shudder thing. I love my truck, but this is driving me crazy.


Any help out there?

Sounds like converter clutch chatter.Converter should have been replaced at the same time.


mike

http://www.dieselplace.com/forum/smileys/Confused.gif You got a "shift kit" installed under waranty? I'm too curious... I want to know more? Wich shift kit was it?Edited by: Maxter

I don't know the name of the kit, but I can find out if it is important.


The guy showed me the bulletin and diagrams for the upgrade. I assume it was from Allison Trans tech folks. He called it a shift kit and that the cost of the upgrade was $2000. Glad I do not have to pay for it.


The bulletin listed several problems the upgrade addressed. I don't remember all of them, but the problem with reverse not working after sitting a period of time was one of them. The other was going into neutral under a heavy load. I had not had either of those problems - just the shifting shudder.

I don't know the name of the kit, but I can find out if it is important.


The guy showed me the bulletin and diagrams for the upgrade. I assume it was from Allison Trans tech folks. He called it a shift kit and that the cost of the upgrade was $2000. Glad I do not have to pay for it.


The bulletin listed several problems the upgrade addressed. I don't remember all of them, but the problem with reverse not working after sitting a period of time was one of them. The other was going into neutral under a heavy load. I had not had either of those problems - just the shifting shudder.








Gee if GM was paying for an upgrade I would have gotten in line.........http://www.dieselplace.com/forum/smileys/Embarrased.gif


I would have even offered to pay for the fluid.........and new spin-on......http://www.dieselplace.com/forum/smileys/HiHi.gif http://dieselplace.com/forum/smileys/HiHi.gif http://dieselplace.com/forum/smileys/HiHi.gif





Thttp://www.dieselplace.com/forum/smileys/Clown.gifNY

Transgo is taking a lot of tech calls from Ally dealers. Seems the Ally manuals are good for 2 months before they change their minds. I have bought 3 sets of Ally manuals in the last 6 months and they are all outdated. Time for new ones again ( 150.00 a shot). I think women might be running this company. http://www.dieselplace.com/forum/smileys/HiHi.gif


mike

careful Mike post could be misconstrued as harsh..........http://www.dieselplace.com/forum/smileys/HiHi.gifYou might get placed on double secret probation ......welcome Mr Adams...........please tell us more about the "shift kit"........it will stir alot of interest here

It may be the drain back tsb wich include a new valve in the pump among other stuff. It's probably not a shift kit in the "transgo" sort of way; just a few upgraded parts.

Mike L.: Does the Ally book you're selling ever gets updated like the genuine ally books you're talking about?

There will be an update in the Transgo book. Steve Younger and Dave Hardin are working on it now. ( pages to be added to your books) As far as the Allison manuals; you have to be very carefull what you read out of it and what may or may not pretain to our trucks. A lot of the stuff in the "Holy Book of Grail" doesn't mean diddly to GM owners Allisons ( different breed). I have also found out that what the Allison tech school teaches their techs is a whole lot different than what they print in the book.


mike

Bump

It has taken awhile, but I am back with the name of the upgrade. The mechanic tells me it is a Transgo. It did not fix the problem. However, I had him ride with me again and the transmission did its "shudder" for him. I told him that someone on the forum had suggested it was converter clutch chatter, the second time it did it the mechanic agreed (thanks mike for the tip).


So, the truck is going back into the shop next week for them to try to correct the problem.


Thanks for all of your help from a total novice.