2005 2500HD Transmission Issue

[stravis]

I have a 2005 Chevy 2500HD with the 6.0L and automatic transmission. Love this truck. I've had zero issues and have about 85,000 miles. I changed the transmission fluid at 35,000 and again at about 60,000. It shifts very smooth and makes no abnormal noise. I tow fairly often and keep a close eye on the trans temp gauge and have never seen it climb over about 175 or so.

Occasionally, and by that I mean maybe twice a year, I will start it up cold, put it in reverse and the engine will rev, but the truck will barely move. Almost seems the transmission is slipping, as if I have a foot on the clutch (it's an automatic). After a few seconds, it gains full power and will act completely normal. Like I said, it happens maybe twice a year if that. It happened again a few days ago. Fluid level is fine, it's red and smells normal.

Is this something I need to worry about or get checked? Is this a common issue?

Thanks in advance for the help.

 

[crbr]

I have a 2005 Chevy 2500HD with the 6.0L and automatic transmission. Love this truck. I've had zero issues and have about 85,000 miles. I changed the transmission fluid at 35,000 and again at about 60,000. It shifts very smooth and makes no abnormal noise. I tow fairly often and keep a close eye on the trans temp gauge and have never seen it climb over about 175 or so.

Occasionally, and by that I mean maybe twice a year, I will start it up cold, put it in reverse and the engine will rev, but the truck will barely move. Almost seems the transmission is slipping, as if I have a foot on the clutch (it's an automatic). After a few seconds, it gains full power and will act completely normal. Like I said, it happens maybe twice a year if that. It happened again a few days ago. Fluid level is fine, it's red and smells normal.

Is this something I need to worry about or get checked? Is this a common issue?

Thanks in advance for the help.

After sitting for a few days, the fluid drains to the bottom and the pump has to pick it back up for redistribution. Mine does the same thing (have had 3 different Allisons in the HD series). It's normal under certain and predicted conditions. Let it idle up for about 2 - 3 minutes and it will do just fine. The Allison is a fine transmission as long as you keep a stock tune on your ECM.

 

[stravis]

Thanks for the response. I should have been more specific in the original post. Mine is not the Allison transmission. It also happens after only sitting for a few hours. It happened a couple days ago after sitting in the parking lot of my office for about 8 hours. It's also warm here right now.

I'm thinking I might be slightly hitting the gas before the shifter gets into reverse and the computer knows to take it slow at first, if that makes sense. Kinda like a JD with powereverser, you don't have to clutch to go from forward to reverse, but if you don't it slowly applies the power when you shift. That's what it feels like. Hopefully it's just the computer protecting the transmission from my eagerness.

Could that be it? Anyone know if a chevy computer does this?

Thanks again for the reply.

 

[timswi]

I don't have your set up. My GMC tranny acts up for 10 minutes r so a couple of times a year. Computer confusion is my guess.

I'm pretty sesitive to this issue, so I took mine back to the dealer. The put a "flight recorder" in it so that I could record the ECM every time it acted up. GM engineering found nothing. They said that a true fault will show up on the dash message.

 

[Diamondpilot]

Sounds like its loosing prime to me and a torque converter is the problem. Not sure if yours is the same but about a mouth ago I pulled out a 2500HD 6.0 4x4 with my Titan and he smoked the tranny. It was a newer truck with the new body style and big front bumper. He was trying to get it out before I got on the scene and by the time we got it out of the snow bank it had a "tranny hot" message/dummy light on the dash and would not go in any gear, forward or reverse.

Chris

 

[stravis]

Sounds like its loosing prime to me and a torque converter is the problem. Not sure if yours is the same but about a mouth ago I pulled out a 2500HD 6.0 4x4 with my Titan and he smoked the tranny. It was a newer truck with the new body style and big front bumper. He was trying to get it out before I got on the scene and by the time we got it out of the snow bank it had a "tranny hot" message/dummy light on the dash and would not go in any gear, forward or reverse.

Chris

Sounds like he overheated his trying to get out of the hole. Mine does this when it's cold and is back to completely normal in about 15 seconds.

 

[WH401]

Thanks for the response. I should have been more specific in the original post. Mine is not the Allison transmission. It also happens after only sitting for a few hours. It happened a couple days ago after sitting in the parking lot of my office for about 8 hours. It's also warm here right now.

I'm thinking I might be slightly hitting the gas before the shifter gets into reverse and the computer knows to take it slow at first, if that makes sense. Kinda like a JD with powereverser, you don't have to clutch to go from forward to reverse, but if you don't it slowly applies the power when you shift. That's what it feels like. Hopefully it's just the computer protecting the transmission from my eagerness.

Could that be it? Anyone know if a chevy computer does this?

Thanks again for the reply.

It's the fluid issue as CRBR mentioned. It's not a serious problem, it's normal, and it effects any automatic transmission, especially one that has sat for a while. You need to let it idle in neutral for a few minutes so that the fluid gets fully circulated through the trans after sitting for so long. If it's only sat for a day than you'll be fine with just letting it idle for 30 seconds since not much fluid will have drained out of the entire trans. If you just drop it right into drive, the torque converter is dry and has no fluid, and thus nothing to transfer power to the wheels with. Torque converters rely on fluid to work properly, through fluid coupling. Not to mention, engaging the torque converter without any fluid in it causes damage over time.

 

[Diamondpilot]

While I agree with what you guys are saying its not right. I have owned well over 25 vehicles all but 2 with automatic trannys and have only had a similar issue with one, my Dodge 2500 Hemi. There is a problem. Its got to be with the prime of the torque converter.

If its under warranty I would make them fix it. It should not be that way period. It would be another story if it were a 15 year old truck you used just to beat around in during hunting season or to run to the hardware store.

Chris

 

[stravis]

Thanks for all the responses, guys. I really appreciate the help.

 

[WH401]

After you start the truck, and it's been sitting for a while, do you immediately drop it into drive? What I mean is, do you wait a minute or two between the time you start the truck and the time you drop it into drive?, or do you just do it immediately?