4L80E rebuild for my 1028A3

[FMJ]

Ok,

So I picked up a 4L80E from Ft. Riley a couple years back and am now rebuilding it to go in my truck. Here are some pic's of the teardown.

 

[FMJ]

more pics

More

 

[Warthog]

Great man cave.

I picked up a transmission holder a couple of years ago. I have a 4L80E, a 700R4 and a couple TH400s that need rebuilding.

 

[NDT]

Does it have "park" position, and if not, tell us how painful it is to add it.

 

[rsh4364]

Lots of credit to you,if I attempted this my brain would be spaghetti! What are your thoughts on using a manual valve body to eliminate controller? On the 4l80e.

 

[Recovry4x4]

Nice. I wish I possessed the skill set to do auto trans. Sucks having all these 700R4s I can't use.

 

[FMJ]

Lots of credit to you,if I attempted this my brain would be spaghetti! What are your thoughts on using a manual valve body to eliminate controller? On the 4l80e.

Already bought the compushift controller, I personally would rather have some one else do the shifting for me under NORMAL circumstances. . . .

 

[FMJ]

Does it have "park" position, and if not, tell us how painful it is to add it.

It has park, it's a tranny out of a HMMWV, I also have a civi tranny out of a 97 C3500 to replace all the parts that are missing.

 

[Warthog]

I have been told you only need to add the park paw to the HMMWV tranny. YMMV

 

[FMJ]

This one had the park paw, I had to drive out a pin to get it out, it was at the rear of the trans on the drivers side.

 

[FMJ]

Ok, some more info on the teardown. The rear oil cooler fitting on the transmission MUST be removed prior to removing the rear gear assembly, ask me how I know. . . . The ATSG manual, and the HMMWV manual do not indicate it needs to be removed prior to removing the the rear gear set.

My GL 4L80E is a 2010 model and the oil cooler fittings are different than the 07 and earlier, the earlier fittings are 1/4" thread the 08 and later are 9/16"

The rear fitting is critical because it plugs into the rear gear train assembly and is the first place the oil goes after being cooled in the trans cooler.

 

[FMJ]

The part number for the 97-07 fitting is 24233367, the part number for the 08 and later is 24236581


http://www.tonkinonlineparts.com/p/__/FITTING-Transmission-Oil-Cooler/6598477/24236581.html

 

[FMJ]

Ok, so I'm going back together this weekend with the new parts, and the 4WD short shaft. Remove the snap ring on the output gear assembly and swap in the short 4WD output shaft. I'll try to get a P/N for the correct 4WD shaft.

 

[Warthog]

How did you clean the case?

 

[FMJ]

Spray on engine degreaser power washer with hot water and then compressed air. The case was very clean to begin with. I thought about taking it and having it cleaned, but it came out just fine with a driveway power wash.

Wait, I just realized what you where asking, there are actually 2 transmissions. A HMMWV unit from Ft. Riley, shown all shiny, and a long tail shaft unit out of a 97 C3500. The HMMWV transmission was missing parts, the goal is to make one complete transmission from the 2

 

[Keith_J]

So you are marrying it to a NP208 transfer case? Is that why you need a short output shaft?

I was under the impression on the 4L80 you could use a 2WD shaft trimmed down to fit, the transmission to transfer case adapter substitutes the tailcase housing on the transmission.

I plan on putting a 4L80 into my M1031, the above info is what I have gleaned over the internet. Oh, the 1031 has a NP205 transfer case, minor machining is required on the adapter to fit. Just a few thousandths off the diameter...

 

[FMJ]

Yes, going to a 208, the TH400 to NP208 adapter wont work because the adapter centering ring is to big to plug into the transmission housing, 4L80E, so, I bought a 4L80E to NP241 adapter off epay. The unit on the left is the stock 400 to 208 adapter, and the one on the right is the 4L80 to 241 adapter. only thing I need to do is space the rubber mount out enough to make it match the TH400 adapter.

 

[TexAndy]

I have been told you only need to add the park paw to the HMMWV tranny. YMMV

I believe that's just the TH400 equipped hmmwv

I have a few of those. NSN ending in 2136