My buddy has an 01 Suburban 2500 with an 8.1L, it just hit 100K a few months back. This past weekend we went on a camping trip and it was fine the whole way there, until we tried to park it and realized it had lost reverse. Seems to shift ok under regular driving, but one other thing we did notice is when you put it in 1st gear and start going, it wont hold its RPM's.

Ex: If i put it in 1st gear and slowly drive up to about 20-25mph and its at 3K RPM, and i let off the gas... the RPM just drops down to idle and doesnt hold. And if i try to give it some gas, it will rev back up to 3K before i moves again.

Any ideas before we pull the trans?? We already did a fluid and filter change on it and the fluid looked fine when it came out and didnt smell burned at all.

 

Your buddy has an issue with the low/reverse band.

 

vince thats my cousin zoran btw ^^^

 

Thats what i figured it was, i'll let him know. Thanks Vince

Tony- Its Tims suburban that took a dump...

 

dam that sucks. Tell him to buy a new trans at sema lol

 

You think they'd let us bring it on the plane with us?? LMAO

 

The tab on the low/reverse band has probably broken off. Somewhat common on 80's with high milage.

 

That's odd,
I've torn down hundreds of 4L80Es and TH400s (same band) and NEVER seen or even heard of that failure.

 

I've seen it a few times but its more common to see the band cooked! Another thing guys talk about is the servo breaking and to be honest I have only seen in twice with all the units I have built. Either way the trans needs to come out.

 

X1000....never heard of the tab breaking myself...