Allison slipping

[rsgs]

After not driving the truck for four or more days (it's happened twice now), after I start the truck, place it in drive, there is some slippage in the trans as I pull away. It seems to go away by the time I hit the first Stop sign on our street (about 1/4 mile). Wondered if anyone else has experienced this and if it's a problem, or an issue of not driving it for a while. My first thought is that it shouldn't be doing this. Fluid level is fine and filter is changed on a regular basis. Any input would be appreciated.

[jbplock]

Could be your torque converter is draining back to the pan.. Does it still slip if you let the truck idle for a while in park before pulling away?

See the following topic for more info ... allison drain back (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=7;t=005451)

smile.gif

[rsgs]

I don't know about letting it idle. I never had the problem before. I was driving the truck almost daily but I have been working from home lately and have been riding my Gold Wing just around town for errands, etc. The two times I drove it last, I started it up, let it idle for about 20 second until I fastened my seat belt, then put it in gear and drove away. Both times it slipped for a short period of time, then seemed fine.

Interesting link you posted on the first reply. I have 53k on it now so I'm not sure it will be covered. GM doubled my warranty on the engine when I went through the injector fiasco, but I don't think it extends to the trans.

[Buck]

Can you describe "slippage" better :confused:

[jbplock]

Originally posted by rsgs:
... I don't know about letting it idle...If the problem is converter drain back, letting the engine idle in park before selecting drive should refill the converter and stop the slippage.

[rsgs]

BUCK: By slippage, I mean when I put the truck in gear and press the fuel (not gas) pedal, the rpms go up, the truck moves a little. I can rev the truck in gear and the speed does not increase. Over a bit of time (1 minute or so), the trans seems to catch up to the rpms and the truck begins to move. Then everything seems to be ok.

[Buck]

I think I would at least talk to Eric Merchant about your problem. "Dmaxallitech" as he is more commonly known. GMdieseltech.com

How far from Grand Rapids are you? That is where he located. He is the most qualified tech in your area on these trucks.

[Dewey Faircloth]

Have a 2005 and when it sits a few days it will not move until it runs a short time.Temp in 90's
Probably not a minute.
Does any one know a fix for that?
Have changed the filters regular.
23,000 miles.
have read the fix for the 2001-2003.

[madmatt]

several possibilities, weak batteries, bad ground, debris in convertor flow valve, etc....It really needs to go to the dealer. Too many possibilities to diag via internet...

[Dewey Faircloth]

Thanks,will take it to the dealer.

Dewey

[LTChip]

I back out of my parking spot in the AM and once in a blue moon, I will pop her into R and touch the accelerator and it acts just like she is in N. It clicks into gear after about 5-15 secs and no other problems the rest of the day. This will happen once every few months or so and I drive everyday. It seems like a problem with the shifting from P to a drive gear when I do so quickly after starting her up.

[Washman]

I have a 2004 2500 HD with a very similar problem which I first noticed about 3 weeks ago. I use the truck to tow my fifth wheel & only start it up once a week when not towing. When I try put it in drive after starting, it acts as if it is in neutral. If I increase rpm for about ten seconds the truck will move & is fine afterwards. The dealer has asked me to leave it at their shop for a few days & they will check it out. I wonder if anyone is aware of a service bulletin regarding this problem. I read an earlier post which said it could be several problems, including weak batteries. How could weak batteries affect not moving in Drive? Thanks in advance for any info which I can use. I read the info on the 2003 recall, & my dealer says that problem was only thru 2003 & the newer transmissions had an update for the problem.

[Washman]

Just an update for everyone. I took my 2004 Silverado 2500 HD to my chevy dealer to have this problem looked at. The dealer confirmed my problem & contacted the tech line people at GM. They are aware of this problem & there is a "secret bulletin" about it. However, GM says there is no fix for the problem. It is acceptable at this time for the truck not to move in drive if the truck has sat for 3 days or more. The solution is to rev the motor in drive until the truck will move. I have told the dealer that this unacceptable & a dealer rep is supposed to contact me within two weeks. According to my dealer, GM will offer me a "Component Letter" which will extend the warranty on the transmission for up to 100,000 miles to assure me that this is not a problem. Does anyone have any thoughts on this? It seems totally unacceptable to have a truck which will not move in Drive until after 15 seconds.