Thought I’d share my most recent work project . I have done several of these transmissions with the same issue. 3-4 upshift slip or flare between shifts. Here are some disassembly pics. Enjoy.

A few more. Assembly pictures will follow once parts come in

That transmission was way to clean to have failed. I think you're pulling our legs.

Dang, those clutch disks are shot! What's the root cause and fix?

It doesn't look as complicated as I thought but those clutches are thin!

Clutch worn out? or glazed?

Worn down to the metal zero friction material left on half of the friction plates in that set. Forward, direct, and low/reverse were worn beyond maximum limits and the overdrive was worn 5 times max limit. I am very impressed how well the TCM adapted to the wear. This particular clutch (overdrive) has too little surface area compared the others in the transmission. There is an aftemarket clutch drum that has 50% more holding power from increased clutch count but requires a billet intermediate shaft and billet input shaft (which also acts as overdrive drum) to a tune of 1500$. Not a reasonable cost for a municipality. This truck is a F450 rescue with a 6.7 powerstroke. Just over 100k miles. It’s gstting a full overhaul. There are several updated hard parts too ford has made over the years.

This transmission is not bad to rebuild. Some special tools are required specific to this unit. They are also heavy 325lbs dry. The input assembly alone all together weighs 80 lbs . Its 4 pic up from bottom on the left.

What are you finding as the main problems?

I am working with an AT shop near here developing a rebuild ATF. The MERCON® LV fluid doesn't seem to have the FM longevity needed for 150,000 mile OCI's.

In addition, while the dual filter system removes particulates, the quick lockup feature of the TCC on upshifts shears the fluid pretty fast.

Thanks for the pics were those trannies in a gas or diesel engine? the trans in huge !

This is a diesel application. However the physical size between gas and diesel are the same but internally some differences. It has 6 forward ratios and a torque input capacity of 1400 lb ft.

Molakule, you are correct. In this application 150k miles is far too much for the fluid. The trans made it barely 2/3 of the way there. Ford now sells a friction modifier called XL16 and recommends using it after an overhaul. The torque converter clutch is used far more than the previous generations of the torqshift and can definitely contribute to shear. These transmissions are also designed to operate at around 200*F fluid temperature. The main issue I feel with this transmission is the overdrive clutch surface area. It was also designed with a molded rubber piston and all the other clutch sets use a solid aluminum piston with lip seals.

I’ll try to have some more detailed pics of the individual components when I reassemble it.

Both gas and diesel.

Thanks for the info. The shop is very hesitant to use an MoDTC amide additive since this is an organo-metallic FM and we don't feel this is going to fix any problems.

Is your shop seeing many of the 60R140 trans with problems? I am a fluid and filter changer when the unit is new then sooner than later after the break in oil change

Right around 100k miles they start to develop issues. The 450s tend to show up faster than the 350s. My only guess is due to weight. Keep in mind a majority of the trucks I see have very hard miles. Constant run time with lots of city driving with hills. This particular truck has 17000 engine hours with just over 100k road miles. By the hours it’s approximately 560,000 engine miles.

Has this transmission ever been serviced through out the time it was in service? I would have thought that they would have at least one fluid and filter change in that amount of miles due to the severe operating environment they are used in.

No it has not. It makes too much sense to do that. The person that is in charge of the department does not believe in routine fluid changes (other than engine oil). I have convinced him otherwise as this is the 7th transmission failure in 2 years in rescue fleet alone.