4L80E Information Thread

[PEIslander]

Excellent thread! Am I reading correctly that the 1994 4L80 is a one year only design so if mine craps out I need to get parts or another trans specific to this year only? That might be fun...

 

[NickTransmissions]

Excellent thread! Am I reading correctly that the 1994 4L80 is a one year only design so if mine craps out I need to get parts or another trans specific to this year only? That might be fun...

It's one year only owing to the elimination of the OSS in the 4x4s, elimination of the torque signal compensator valve and 1st design EPC in the valve body assy so the valve body, accumulator body EPC changed. Additionally, it's the last year without the manual lever position sensor, which began in 1995.

You can retro a 1995 or 1996 but you'll need to swap to the shorter 91-94 selector shaft and ditch the mlps if it's still bolted to the case. You can even retro a 97+, same as far as selector shaft swaps plus running 97+ cooler lines.

 

[TimBo1951]

I have a question My 4l80e is making a metallic sound going in and out of 4th. Have you had this show up anywhere and what is the root cause and repair? Thanks in advance for any help.

 

[NickTransmissions]

I have a question My 4l80e is making a metallic sound going in and out of 4th. Have you had this show up anywhere and what is the root cause and repair? Thanks in advance for any help.

Are you positive the sound is coming from the transmission or torque converter and not something else?

Noises are the toughest thing to diagnose over the internet, primarily owning to the fact everyone has their own interpretation/descriptions of the soundsn they hear. The one exception to this is grinding noises. That's pretty universal and only means one thing.

Any drivability symptoms, apart from the sound?

 

[TimBo1951]

My name is Tim . Just the definite sound going into and out of 4th. The sound is a definite sound most different from anything prior. I can select 3rd and of course it is not shifting to 4th and it doesn’t make the noise. Did a definite road test with a retired transmission mechanic. It was new to him but he has no desire to dig in.

 

[TimBo1951]

The closest reliable qualified tranny shop is 50 miles away.

 

[NickTransmissions]

My name is Tim . Just the definite sound going into and out of 4th. The sound is a definite sound most different from anything prior. I can select 3rd and of course it is not shifting to 4th and it doesn’t make the noise. Did a definite road test with a retired transmission mechanic. It was new to him but he has no desire to dig in.

Any problems/symptoms with the transmission apart from the noise?

 

[XxEasyxX]

Awesome write-up. In the middle of swapping my 88 to a 6.0 4l80e combo and can't find any info on what needs done with the driveshaft or if I can just use one from a stock 4l80e obs. The combo came from a 03 2500 and I have that output shaft. My truck was a 350/700r4 2wd rclb. I did find one person say you get a swap u joint and get your driveshaft shortened but I feel like since these trucks came with a 4l80e that a stock driveshaft is out there for me.

 

[NickTransmissions]

Awesome write-up. In the middle of swapping my 88 to a 6.0 4l80e combo and can't find any info on what needs done with the driveshaft or if I can just use one from a stock 4l80e obs. The combo came from a 03 2500 and I have that output shaft. My truck was a 350/700r4 2wd rclb. I did find one person say you get a swap u joint and get your driveshaft shortened but I feel like since these trucks came with a 4l80e that a stock driveshaft is out there for me.

Thanks, man.

There may be a driveshaft that will work as-is but most of my customers doing these swaps have theirs cut and balanced; usually runs around $100-$125 (one piece shafts).

 

[XxEasyxX]

Thanks, man.

There may be a driveshaft that will work as-is but most of my customers doing these swaps have theirs cut and balanced; usually runs around $100-$125 (one piece shafts).

Oh wow did not realize it's so inexpensive. Thanks for the info.