1991 4L80e sluggish when cold

[eodcoduto]

The suburban is acting up when it is cold, it takes a bit to get reverse to engage and 1st is a little better. Once I go down the road everything is fine and it shifts good, locks up when it is supposed to and no flaring. I pulled the pan and changed the filter and the pan was clean, no clutch material at all and the inside of the trans was clean. I'm hoping there is a simple fix for this.

 

[Chickntrk]

My TH400 did this until I changed the filter from the Dacron one to the mesh screen one….not sure if the 4L80E has that option or not

 

[HankScorpio]

Mine does this once in a while. 1991 V2500 burb. Takes a couple seconds to engage R first thing in the morning sometimes. Works flawlessly the rest of the time.

 

[centexk5]

Cold fluid takes longer to flow and get the circuits pumped up. My old dodge I would let idle in neutral while I got my seat belt buckled and radio set and what not. Never an issue.

 

[Chickntrk]

Cold fluid takes longer to flow and get the circuits pumped up. My old dodge I would let idle in neutral while I got my seat belt buckled and radio set and what not. Never an issue.

Dodges are famous for this because they only pump in neutral, not park, I always did similar to you

 

[centexk5]

Park, neutral, just give it a few minutes to pump up before shifting.

 

[wheels87k5]

Isn't it odd........when these vehicles were brand new there was never a problem with the sluggishness or pause when putting them in any gear?

 

[eodcoduto]

Yea something isn’t right but I’ll get it figured out.

 

[centexk5]

Isn't it odd........when these vehicles were brand new there was never a problem with the sluggishness or pause when putting them in any gear?

Stuff wears out over time. I’m not familiar with gm transmissions but there may be something as simple as a check valve that’s worn out and not holding fluid in the converter anymore.

 

[Blue85]

What's the word on switching the 4L80 over to Dex VI?

 

[eodcoduto]

Thats what I run, looks like it was a bit low and splashing up on the stick making it look full.
I’ve had this for a year now and it’s never been as quick to go in reverse as it should, but I’ll keep going until it dies then get a new one.

 

[tarussell]

Showing signs of age….one thing to do is give it much longer to warm up when it’s cold before driving off so the fluid and pressure is all good.
Also even though it’s not an issue when it’s warm giving it a little time to warm up before driving will aid in longevity for an older trans.
Just like all of us - none of us can jump outta bed in the morning and instantly start running anymore; gotta give a little time to get the fluids moving and warmed up.

 

[eodcoduto]

Showing signs of age….one thing to do is give it much longer to warm up when it’s cold before driving off so the fluid and pressure is all good.
Also even though it’s not an issue when it’s warm giving it a little time to warm up before driving will aid in longevity for an older trans.
Just like all of us - none of us can jump outta bed in the morning and instantly start running anymore; gotta give a little time to get the fluids moving and warmed up.

Amen!

 

[wheels87k5]

In the 2005 Suburban the 4l80e was doing what you are describing. Sometimes it would engage immediately and sometimes it would pause for a few seconds before going into reverse. It didn't matter what the temp outside was. The transmission shop kept it and was able to verify that it had that "pause". I had them rebuild it and it still does the same thing. It doesn't overheat or shift hard and it's got 12,000 miles on it since the rebuild.

 

[1-ton]

Problems with reverse could be in the servo being a little out of adjustment, or the reverse servo piston seals not holding 100% when cold.