Allison question??

[woodgriz]

We have a stock 2004.5 LLY, with 13,500 miles, the truck sits in the garage for several weeks at a time. I have noticed when I put it in reverse after one of the garaged periods that the transmission acts like it has to pump pressure up before it begins to move, this condition only lasts for a few seconds, any thoughts?? Ideas, suggestions? Maybe this is normal? Everything else seems to work great.

Thanks for any and all help
Woodgriz

[SSonnentag]

My 2000 Dodge Durango (gas) has done the same thing since day 1. It doesn't seem to hurt anything. I have 100,000 miles on the Durango without any tranny problems whatsoever.

Shawn

[aero]

My 2004 Has Acted That Way Since Day One. Dealer Says No Problem. Gm Knows About It But No Fix. Make Sure Dealer Documents It!

[Kennedy]

I typically like to wait a minimum of 15 seconds before moving the selector after any start. Let thinks get flowing and normalize first. Longer in cold weather also.

[woodgriz]

Thanks for the responses, good ideas on letting engine run a bit longer after a garaged period and having the dealer document this condition.

woodgriz

[madmatt]

When I was still in the shop there used to be a bulletin out that pertained to a problem like you describe that I fixed several times. Weak pressure control springs in your pump hsg. It's an easy fix but the tranny does have to come out if that indeed is your problem. I'll see if I can come up w/ a bullitin #. I think I've posted it here before.

[Heartbeat Hauler]

Mine does this when I let my truck sit for a long period of time (more than a week). I wait a few seconds then with my foot on the brake, I put the selector in each gear then reverse and back to drive. I've only had to do this 3 or 4 times in 5 years but that's what I do. I'm sure the torque converter is draining out and needs a second or two to fill back up.
JP

[madmatt]

Thats exactly whats happening. The pressure control valves/ plungers are suppossed to close @ shutdown to prevent torque convertor drainback but the original springs in many are to weak to seal tight enough to prevent it. Pull the tranny, pump, plungers and R&R the springs. GM used to have a parts kit just for this repair. It had all the gaskets and springs you needed.

[aero]

madmatt, how about the bulletin # so i can have dealer look it up. thanks

[madmatt]

Hope this helps...It says up till 03' but the described problem fits this to a T. Your dealer should be able to pull this up and call TAC if they have anymore questions...


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Subject: Allison Transmission Delayed Engagement, Cold Hesitation, MIL Illuminated, DTCs P0701, P1709, P1711, P1713, P0841, P0843, P0847, P0870, P0872 or P0875 (Replace Torque Converter Relief Spring) #03-07-30-011D - (10/19/2005)



Models: 2001-2003 Chevrolet Silverado 2500/3500 Series

2001-2003 GMC Sierra 2500/3500 Series

with Allison

[More Power]

Matt, Thanks for the info...

The three different Allison transmissions I've had would do this if the truck sat for more than a week (usually about 10 days). Never set any codes though. Also, as the TC drains back into the trans, fluid level can rise to a point where it'll begin to slowly seep out at the rubber lip seal where the dipstick tube enters the transmission, and then drop onto the garage floor.

About 30 seconds of idling in reverse corrects the problem. :)

Jim

[madmatt]

Hey Jim! Sorry I've not been around much lately, the new job along w/ all the other BS going on here has kept me more then busy. As for the problem, some will set codes, others will not. I wouldn't consider it a problem that may damage your tranny further but if it really bothers you, it is an easy fix if you don't mind dropping the tranny.

[aero]

THANKS! now off to the dealer!

[dmaxalliTech]

The valves have been redesigned in the 04 MY and newer Alli's. The springs will not fit, but it still could be a drainback issue. After shutting off your truck, let it sit for a few minutes then check the fluid level. Note its location and check it agian after an overnight sit. It will be a good inch higher likely if drainback was the issue.

[madmatt]

Good to know!! I hadn't messed w/ this condition on anything newer then an 04 so I wasn't 100% sure if this bulletin could carry over.

[dmaxalliTech]

Matt, from what I have seen, it does not carry over, but it seems now they are getting some miles/time on them the problem seems to be there on some rare units.