I'd notify the service shop that did the change and demand a refund, then I'd make sure they know if I had any problems I'd be knocking at their door.

 

whatever you do with the shop, MAKE SURE YOU GET IT IN WRITING.

 

They know about it. They went good for the backflushing and the filter change the second time along with a solonoid (D) that was sticking pretty regularly. The local Ford garage did all the work the second time around and the tech. said that there was a fair amount of clutch fragment in the pan!

 

What usually fails in the 4R100 trans's? Electrical? Hydraulic? Hard parts (clutches) wearing out? What causes these failures? Heat? Would a secondary trans cooler help prolong its life?

 

Read post #28. It's generally heat that causes the failures for various reasons. The cooler in the 7.3s is smaller than the one in the V10s inexplicably. A lot of guys replace the stock cooler with 6.0 (the largest of them) or the V10 (between the two). Some others add the Tru-Cool inline which gets mounted in front of the AC condenser. If you want the tranny to last the absolute longest, put in a good kit to keep the shift durations down and increase the holding pressures on the clutches. Then put in a much more efficient (read: less heat!!) torque converter. Either the 6.0 or an aftermarket will do. Also, aftermarket programming (like from DP-Tuner) in the PCM will also increase pressures and improve shift strategy.

The heat in the stock trannys gets generated in the clutches that take too long to shift, then don't have enough holding pressure so they slip under heavy loads or hard acceleration. It also is generated by the TC. If you put in a good shift kit or custom accumulator valve body, change to a more efficient TC, add custom tuning, and put in a bigger (or second) cooler, the tranny will last a nice long time...

EDIT: I've done everything but the extra cooler (which I will do in the Spring), and the torque converter. If I towed heavy, I'd seriously consider changing the TC, but I don't. I also put in full syn Mobil 1 ATF (Mercon V rated). Syn fluid is better at handling heat that does get generated, so I think that's a good idea, too.

 

Does this extra heat generated in an automatic transmission show up on the trans heat gauge?

 

good question. I have a temp gauge in mine and never seen it move. I was almost stuck the other day, pulled in a muddy driveway (guy is building a house) and the trailer was loaded at the rear. I barely got off the road and sank 6 inches in greasy mucky black mud. Anyway, I ended up rocking the truck and tri-axel trailer quite a bit and only moving a few feet at a time. The entire time I was doing this, the trans temp gauge never moved. Is this right ?

 

The stock trans temp gauge will stay right in the middle when the trans temp is between 50F and 230F. If it gets above 230F it will go to the yellow, and if it gets above 250F it will go to red.

 

You might want to check your trans oil to make sure it still looks and smells ok.

 

Agreed. And put in a real temp gauge if you really want to see what it's doing. Empty, mine rarely goes above 180 in the 100+ degree summers here, stock cooler. I don't tow much, if at all. I will be adding the Tru-Cool though from here:
http://www.dieselsite.com/index.asp?...ROD&ProdID=205

 

The trans in my 2000 SD with the 5.4 completely exploded at 65,000 miles. It had a massive failure that screwed up everything from the mainshaft to the case.

......and up to that point it had never been used for serious towing. The heaviest thing it had towed was a suzuki samurai (2000 lbs?). My wife used it as her "car".

 

My '05 torqshift has always been solid in the forward gears. Once in a while in reverse the motor will rev up but the tranny just shudders and the truck doesn't move. I thought it was the rear diff and the LS was letting go. From what I've read on these forums, its sounds more like the tranny isn't engaging properly. I bought the truck at 53k and changed the fluid at 65k. I don't know what maintenance was done before I bought the truck. Currently I have 85k with very little towing. Any ideas about where to go from here? I have read that low voltage can cause the solenoids to work improperly. The batteries were replaced 4 months ago and everything was working properly at that time.

 

The Manual is great for highway and extended running in 6th gear. Around town it can get a little tedious, but yoou gotta love the whine with the manual....

 

That's also a symptom of the low/reverse snap ring coming loose. Early '05 models had the old style snap ring that would pop out of the groove. Snowplow prep package equipped trucks got a TSB issued for repairs before the case is ruined, but the rest of us are SOL unless the snap ring pops loose when under the 36K mile warranty.
JL