Help me identify my 4L80E (pictures)

[JoBy]

I got a deal on a 4L80E transmissions.

I am missing the yoke and need a part number or in what vehicles this transmission was used in.

The tailshaft housing is extra long with two ball bearings for a fixed yoke .. or something. There is also a lot of extra bolt holes on the tailshaft housing ... Why ?

 

My tailshaft housing has part # 8661620

 

The seal inside diameter is 55mm.

The bearings inside diameter is 45mm.

 

I bought a fixed TH400 and the yoke outside diameter is 48mm.

 

 

 

 

 

 

 

 

More and full size pictures here:

 

http://w1.605.telia.com/~u60513000/temp/4l80e

 

Thanks!

[GM GIMP]

I'm not real sure, but I believe you have a 4WD model.

Looks like the transfer case will mount to the rear.

Most of these trans. came in '92-2000 trucks with 8600 or

higher GVW. rating and '01 up HD pickups with 6.0L

engine.

[JoBy]

Yes, it looks like something should be bolted to the end of the tail housing.

It is a 1998 tranny.

 

A friend of mine has a 4L80E from a 4WD and the adapter between the 4L80 and the transfer case is much wider and less than half the length of mine.

 

EDIT:

 

I found a picture of what his transfer case adaptor looks like

 

 

And this is the 'normal' 2WD type

 

[JoBy]

Has anyone seen a tranny with the same tail housing as mine?

[Import Hater]

Too skinny for a tranfer case adapter. Maybe it's some type of adaptor to bolt up some kind of PTO setup?

 

Rob

[Larry]

Has anyone seen a tranny with the same tail housing as mine?

Oh yeah, I have seen plenty of those before as they are used in a lot of commercial and RV applications.

 

What you have there for code 18LLP 6 is a 4L80E from a 1998 C3500HD w/C5E & L65 (15,000 GVWR and 6.5L turbo diesel).

 

The adapter on the rear is the mounting point for the brake drum assembly that is used as a park brake.

 

The old 1991-2001 3500HD trucks, 1995-current Chevrolet/Workhorse P-Chassis Step-Vans and class A RV’s use transmission mounted park brakes. The units above 15,000 GVWR did not have a park pawl and used an automatic apply park brake that activated when the shift lever is placed in Park. 4L80E’s park pawl is only rated at 15,000 lbs. vs. 26,000 with the Allison LCT1000. The transmission that you have does have a park pawl.

 

I hope you did not spend much on this transmission, as it is one of the most undesirable 4L80E’s to try swapping into other vehicles. You will have to change the main shaft to a 4x4 or 4x2 style depending what you want to use if for and possibly other parts like the valve body, torque converter, etc. You better recruit a knowledgeable transmission monkey to help you with this.

 

Good luck

[JoBy]

 

Thanks!

 

I think that I got a great deal on the tranny.

The guy I bought the tranny from said that it was a HD with straight cut gears. It was a warranty replacement a few years ago and the shop orderd the HD tranny by mistake. The owner said that the gears was too noicy so the shop replaced it once again. I bought the tranny from a guy that worked at the shop. It has only been used a few miles so it should be in great shape. Actually he had two of them but the other one was broken. I got both for $1100. Later I bought a TCI T-Com transmission controller for $400 and that was only used for three month.

 

So then strange tail housing it is for the parking brake. Then I suppose that the yoke is a part of the brake drum and nothing I want to use.

 

Some background ...

 

I lost 3rd and 4th gear on the th700r4 in my supercharged 1984 Corvette. It lasted about 20 miles after I put the suprcharger on. Last time it broke I had it rebuilt stronger and spent $1500 on it. Then I started looking at other options and found these two 4L80E.

 

The C4 Corvette does not have a normal tranny mount. The tranny tail housing is special on the Corvette and bolts to a C-Beam that also bolts to the rear axle.

 

 

 

 

The extra bolt holes on my 4L80E tail housing are good because it makes it easier to build an adapter and bolt it to the C-Beam.

 

 

 

My main problem was finding out what type of yoke to use and I think I can stop searching for one now because there is probably none to find.

 

Actually it does not matter much and I have a plan on how to proceed now.

 

The bearing assembly removed:

 

Inside of the tail housing:

 

A standard slip yoke does fit the output shaft but I can not use it with the ball bearings. I will remove the ball bearings and replace them with a custom adapter with a standard bearing used with the slip yoke. That type of bearing needs oil pressure but that is not a problem. As you see there is an oil feed in the housing to the bearing area. I have to drill an oil passage from that oil feed thru the adapter to feed the bearing. I also have to remove the oil flow restrictor in the oil feed. ( the ball bearings use much less oil )

 

That way I can use a standard slip yoke.

 

Full size pictures:

http://w1.605.telia.com/~u60513000/temp/4l80e/

 

 

And a short movie (3Mb) of the Corvette a few miles before I lost 3rd and 4th gear.

http://w1.605.telia.com/~u60513000/temp/joby_vette.mpg

[JDahl]

Your transmission in the pictures is designed for a parking brake attached to the trans. You have a heavy duty model and possibly the straight cut planetary gears. This for heavy duty trucks

John