Looking for help with 4L80E transmission on an M1123 HMMWV

[TruckGuy]

Found this

Which E-PROM - G503 Military Vehicle Message Forums

basically AB, AC are for turbo trucks, BA, BB are for non turbo. All that changes are the shift points

What are the shift points for the different chips? Turbo vs NA?

 

[hahnmgh63]

It appears going the older style with the Eproms is a much cheaper way? I wonder if one or the other is more reliable, no reason today why each shouldn't last the life of a vehicle like in a commercial vehicle?
On another 4l80e question. Have any of you seen a HMMWV 4l80e with a Self threading sheet metal screw drilled through the tranny oil pan to hold the filter in place? Some idiot in the Army did that to mine and now I have to plug the hole. Swapped fluids and when I pulled the pan (after removing the crossmemember) it was diffiucult. Pulled harder and the fillter popped out and realized that screw towards the front of the pan threaded through the bottom of the pan and into the filter. I pulled the screw out, replaced the filter and the filter neck sleeve with new ones from Wix and they are in there firmly, don't know why you would have needed/wanted to screw the sheet metal screw through the oil pan. The HMMWV 4l80e in my M998 doesn't have one. Was this just a mechanic trying to cover up a bad job? Trying to keep a filter from coming loose? Making it easier to install the pan and filter past the front of the crossover exhaust?

 

[Mogman]

It appears going the older style with the Eproms is a much cheaper way? I wonder if one or the other is more reliable, no reason today why each shouldn't last the life of a vehicle like in a commercial vehicle?
On another 4l80e question. Have any of you seen a HMMWV 4l80e with a Self threading sheet metal screw drilled through the tranny oil pan to hold the filter in place? Some idiot in the Army did that to mine and now I have to plug the hole. Swapped fluids and when I pulled the pan (after removing the crossmemember) it was diffiucult. Pulled harder and the fillter popped out and realized that screw towards the front of the pan threaded through the bottom of the pan and into the filter. I pulled the screw out, replaced the filter and the filter neck sleeve with new ones from Wix and they are in there firmly, don't know why you would have needed/wanted to screw the sheet metal screw through the oil pan. The HMMWV 4l80e in my M998 doesn't have one. Was this just a mechanic trying to cover up a bad job? Trying to keep a filter from coming loose? Making it easier to install the pan and filter past the front of the crossover exhaust?

I think it would be next to impossible to keep that screw from leaking, was definitely an unwise move.
The early TCM should serve you well.

 

[hahnmgh63]

Cleaned the pan real well, left the screw in but cut it shorter so it wouldn't hit the filter anymore. Piled with a hefty amount of Silicone on the outside of the pan. Going to shop for a OEM pan or one of the new baffled fancy ones if I can find it for a decent price and will swap it out on the next filter/fluid change or sooner if it starts leaking.

 

[TOBASH]

Cleaned the pan real well, left the screw in but cut it shorter so it wouldn't hit the filter anymore. Piled with a hefty amount of Silicone on the outside of the pan. Going to shop for a OEM pan or one of the new baffled fancy ones if I can find it for a decent price and will swap it out on the next filter/fluid change or sooner if it starts leaking.

RWH sold me my replacement pan. Don’t wait

In the mean time, pull the screw and use machine screw and washers top and bottom to seal securely. If Silicone breaks free and clogs the inner workings, you are in trouble.

IMHO

 

[hahnmgh63]

RWH sold me my replacement pan. Don’t wait

In the mean time, pull the screw and use machine screw and washers top and bottom to seal securely. If Silicone breaks free and clogs the inner workings, you are in trouble.

IMHO

I just put the Silicone on the outside of the pan by the bolt head. Definitely wouldn't put it on the inside of the pan. Put in 2qts of oil to cover the bottom of the pan as a test to see if it leaks or seeps. After 24 hrs it's dry but we'll give it a few more days. A few different higher capacity oil pans out there. Anyone know of a HMMWV specific? Otherwise I'll have to make some measurements to see if it fits, maybe an extra quart or two of fluid would help.

 

[hahnmgh63]

Got both the Turbo and non-Turbo Eproms for pretty cheap from Eastern Surplus and ordered the TCM above from Advance Autoparts. Going to take my new AGM Costcom batteries out to the HMMWV tommorrow and see if it cranks and starts. Need to repair one small cable.

 

[donkdonk]

Got both the Turbo on non-Turbo Eproms for pretty cheap from Eastern Surplus and ordered the TCM above from Advance Autoparts. Going to take my new AGM Costcom batteries out to the HMMWV tommorrow and see if it cranks and starts. Need to repair one small cable.

So did the TCM & EPROM work? I have a 1097 that the TCM was robbed.

 

[hahnmgh63]

So did the TCM & EPROM work? I have a 1097 that the TCM was robbed.

Sorry, but the engine seems to be froze up so I haven't tried the Eprom. I could try to plug it in and at least scan it for codes. GovPlanet in the auction ad supposedly showed the engine cranking over but not starting? What could have happened to it between them filming the video and my purchase? Mixed up videos from a different HMMWV? Starter definiety engages after installing two batteries. But it clanks hard as it hits the ring gear but engine doesn't move.

 

[Mogman]

Sorry, but the engine seems to be froze up so I haven't tried the Eprom. I could try to plug it in and at least scan it for codes. GovPlanet in the auction ad supposedly showed the engine cranking over but not starting? What could have happened to it between them filming the video and my purchase? Mixed up videos from a different HMMWV? Starter definiety engages after installing two batteries. But it clanks hard as it hits the ring gear but engine doesn't move.

Take a 1" open end wrench, you will find some flats directly behind the crank pulley, see if you can turn the engine (clockwise)

 

[hahnmgh63]

Take a 1" open end wrench, you will find some flats directly behind the crank pulley, see if you can turn the engine (clockwise)

Thanks, I'll give that a try. M1097A2, Noticed with the dual voltage alternator (my M988 doesn't have it) that you have to remove the surpentine belt to actually get at the crank pulley so no place out front to get at it, didn't reallly look behind if for a place for an open end wrench but now I will. I'm actually 2200mi away from my shop and all of my regular tools, slowly moving here so I'm slowly buying another set of tools as I go along Was going to remove the transmission inspection cover but I really didn't want to pry against the flexplate teeth. Just in case, for preperation, I did remove all of the glowpugs, which looked good, and pumped in some engine oil into each cylinder.

 

[hahnmgh63]

Engine is definitely frozen. Kind of pissed off as the video from Govplanet showed them jumping it and cranking over fine even though it didn't start. Figured that would be a fairly easy fix (Glowplugs, Controller, etc..) I'm thinking they posted the video of a different HMMWV, mixed up on accident maybe but Govplanet says that's the way it goes.

 

[duanejacques]

I have 2 extra 2100-AB transmission control modules that we picked up. They are still in the packaging if you need one.