M1151A1 TRANS FRONT SEAL LEAK? OUT FOR RESEAL OR REBUILD, L/R WHEEL LOCKED AT THE DIFF IS SEEMS

I finally pulled the tranny from my 09 M1151A1 serial 326xxx for a not so small leak coming from behind the torque converter. It looks like it is leaking from the torque converter hole and not the seal rim bit i cant be sure. Any advice on how to diagnose if it is just the seal or if it is the pump? Also, curiously, the left rear wheel is locked (won’t spin) and appears that it is being held up at the differential. It moves very slightly then clanks and stops. The right rear was also not moving but after a few gear selector shifts it began to spin. Then I removed the rear propeller shaft to get the tranny out and the left rear wheel still locked. What could be causing this lockup? Before the trans removal began it started normally, all gears and T/C positions were functional, and it drove fine, just leaked from the bell housing. One more thing, the solenoid on the Transfer case wires were separated or snipped, what does that part do?

Also there are 4 nuts missing from the T/C housing at the rear of the trans. Imagine that!

Thanks for the advice, cant wait to get this Humvee operational After having done lots to get it running and driving.

That seal is not a high failure rate seal, id be concerned something else caused the failure, on the rear diff, have you checked the fluid level?
I just got a customer truck in that was drained of ALL fluids and the rear diff locking up while being towed.
tcase, that’s your signal generator for the electronic speedometer

Retiredwarhorses said:

That seal is not a high failure rate seal, id be concerned something else caused the failure, on the rear diff, have you checked the fluid level?
I just got a customer truck in that was drained of ALL fluids and the rear diff locking up while being towed.
tcase, that’s your signal generator for the electronic speedometer

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Have not checked the fluid yet, sorting the major issues nearly ready to do all hubs and diffs. I’ll check that rear one first.

Could it be the electronics from the TCM or?

"all gears and T/C positions were functional, and it drove fine"

You mean you started and drove the truck before checking/changing all the fluids and filters

Had to!

Mstng65HummrMan said:

Have not checked the fluid yet, sorting the major issues nearly ready to do all hubs and diffs. I’ll check that rear one first.

Could it be the electronics from the TCM or?

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Rear fluids drained and looked new, no burn smell, very small metal bits in l/r fluid. The lock up was caused by the seized l/r caliper. It is off and I have ordered new pistons, orings and seals, it is apart on my bench.

I pulled the r/r also and it seems functional but seals are shot. Both should be back in service soon as the parts arrive.

Look at the rear of the torque converter, is there cool pinwheel looking pattern of dirt/fluid? If so your oil seal is leaking, but does not rule out the possibility of the pump seal leaking as well. If the back of the converter is clean and dry spend the few extra dollars while you have it out and have someone who knows what they are doing pull the pump, inspect, do any needed r&r and complete reseal on the front of the tranny.

So update as of Dec 21, 2024:

Brake Calipers refurbI shed and installed with new AM General Pads and pins, and bled to proper functionality. Pretty dirty gunk fluid flushed prior to install.

The boys at AAMCO got the Trans fixed up. The pump was removed, replaced the front sleeve bushing and front seal for the Torque Converter, replaced the wire harness due to leaking, checked/polished the Torque Converter shaft, checked out the internals and gave it a nice clean. Fluids back in and it is now operational.

I noticed a wobble of the Flex Plate and Torque Converter prior to removal and got a new flex plate installed on the engine hoping to correct that problem. A new Speedo Generator also installed as the wires broke off the old one.

Good News is the Transmission front leak is gone…

Bad News, The same wobble exists now after all the work, flex plate very noticably as before and the Torque Converter a small amount as well.

Any ideas on what might be causing this wobble? inconsistant height Torque Converter mount areas for the Flex Plate?

Bent Torque Converter shaft?

Bent Torque Converter?

Crank issue?

Always n adventure with Surplus Humvee!

How much wobble? 1/16", 1/4", 1/2"? I'm guessing it's not a 1/2" but just want to get an idea of what you're seeing.

Looks like a 1/4 to a 1/3 inch inch, just an estimate from videos. The whole assembly is jerking back and forth in and out of the transmission it seems.

Im thinking the Torque converter was abused/dropped during some previous service or possibly flex plate mount points on the Torque Converter could be different length?

Also the Torque Converter inspection cover had damage and bending, maybe an impact from rocks or another object caused the issue.

My next step is a new Torque converter probably…

Thanks for all the help!

I shimmed the torque converter to flex plate on 4 lugs with washers, there was a difference in the gap with two lugs being taller than the other 4 causing a warp in the flex plate. The wobble has been nearly completely alleviated. Now the r/r hub inner inspection cover is in need of a reseal.

Almost time for some road and trail time!