Originally Posted By: 440Magnum
Originally Posted By: meep
This is by far the hottest running trans I've ever known. 180-210F if it's been running for an hour and the A/C is on. 160-180 if no A/C.
That's one of the gripes with the 41TE, and also why it tends to turn in pretty bad fuel economy in some smaller vehicles that theoretically should do better (eg. the PT Cruiser). It has a lot of internal loss- the 40TES and 41TES versions addressed that by re-introducing the concept of variable line pressure- the original 41TE had a constant (high) line pressure, so the pump was always compressing fluid to the highest pressure the trans needed and the VDC solenoids bled it down to the desired pressures- pretty lossy. Throw in the weight of a van and the TC heat that generates, and you get a pretty hot-running unit.
But as tempting as it is to knock the 41TE for its faults, you gotta remember it was the first fully-electronic adaptive auto trans ever mass-produced- first used in the 1989 model year. Most of the other early full-electronic automatics were pretty lossy as well. The Aisin AW4 used in 1990s Cherokees and some Supras may be very reliable (much more than the 41TE), but is also a real energy-soaker. My AW-4 consistently Cherokee got 3-5 mpg less than my stick Cherokee did, even though the stick was a 4x4 and the AW4 was just a 2wd.
That's good to know about the unmodulated line pressure. helps me understand what I'm dealing with. I'm actually a vast-minority closet fan of the 41TE and family. They've got a bad rap but alot of that was transition from one-size-fits-all fluid culture to everything-is-specialized-fluid. It's unfortunate that there are a couple of stupid little weak spots in them that can shorten their lifespan before any of the hard parts wear. I've owned two 41TEs, and never had any unexpected problems with them, considering their use and history. Also two 41-family units (I don't remember the weird lettering for longitudinal but still FWD....) in a couple of LHSs that never saw maintenance--- one outlasted the car at 200k and the other is going strong around 125,000. They also are very consistent, quick, and positive shifters when maintained. The first one I had saw towing duty well beyond its rating and never missed a beat. This one was never maintained by what I can tell, and is still a reliable unit, just a little balky at its age.
I loved the AW4 in the early year 1993 GC I once owned. sucker had some miles on it and kept going. also a fav. but yeah, it ran pretty hot too.
Helped a buddy pull an AW4 from his FJ60 a short while ago. he's had bad luck with AAMCO keeping it 8 weeks and no work done. We are considering buying some tools and trying a rebuilt at home....