trans slips after truck sits

[dirty-b]

The last couple of times I've went to use the truck after it has sat for awhile the trans. slipped when I was pulling it out of the garage. Is this normal? I park it backed into an attached garage, so I don't want it to sit and idle for a long period of time, but would that help to let warm up more? Thanks, Jamie

 

[MACKIN]

No it's TC drain back issue. Next time let it warm up in neutral .

 

[dirty-b]

No it's TC drain back issue. Next time let it warm up in neutral .

No its not normal, or no its not an issue? Thanks I will let it warm up in neutral from now on.

 

[DAVe3283]

No, that's not normal. It should just drop in gear and go.

 

[dirty-b]

So is it somthing that needs to be addressed, or can I just warm it up in neutral and live with it. Any idea what may be wrong? Did the guy that built in stall something incorrectly? Thanks again:hug:

 

[Mike L.]

It is normal when the sealing rings begin to wear on the pump cover. Nothing to worry about. Just give it a little longer to warm up and fill the converter. This can go on for a couple of hundred thousand miles without any issues.

 

[dirty-b]

Ok, will do. Thanks again guys.:hug:

 

[MACKIN]

It is normal when the sealing rings begin to wear on the pump cover. Nothing to worry about. Just give it a little longer to warm up and fill the converter. This can go on for a couple of hundred thousand miles without any issues.

But if he has never addressed the TC drain back issue could that be his problem other than the seal? It's a know issue (drain back) in the early trucks. Even the fix isn't a guaranty but it does help. I wouldn't just pull the transmission to fix this unless it became a real nuisance myself.I'd just let it warm up in neutral as mentioned.

It can't be good to stab the throttle in drive although when this occurs.

 

[Mike L.]

Mack
The problem was always the sealing rings but Allison did not want to address it at that time. They came up with a band aid with the 2 springs for the lube valve and they knew it was not a total fix. Sometimes it worked and sometimes not. The problem was fixed about a year ago by an Allison engineer working at the Baltimore plant. These same rings are now being used on the LML Allison transmission and will retro back. Allison claims this will fix the problem. So far it's working for me.

 

[MACKIN]

Oh I understand its one and the same the reason or what causes what is known as drain back. Thanks for the info I thought there was two issues :thumb:

 

[Grizz3500]

My LBZ does the same thing. If I don't drive for 2-3 weeks, it takes a few seconds before it will back out the shop. Not too worried about it. Did the same thing before Mike built my trans..