by "Urambo Tauro" (urambotauro)
Published 04/13/2017 at 18:00
by "Urambo Tauro" (urambotauro)
Published 04/13/2017 at 18:00
Tags: 41TE
; Automatic Transmission
; Rebuild
; Blog
STARS: 6
The 41TE is one of those computer-controlled transmissions. It has a mind of its own.
It even practices “adaptive shifting” in an effort to adjust to one’s driving habits. Now, TBH, that stuff is all black magic to me. Fortunately, the shift kit’s instructions included a handy little guide to a recalibration procedure known as a “fast re-schedule”, AKA “quick learn”. This must be performed before a road test to prevent damage.
With the wheels off the ground and the shifter in OD, one must gently accelerate up to about 50 mph, coast back down to about 20, then gently brake to a stop. Then again. And again. At least seventy-five times .
The shifts were very distinct, nearly slamming into each gear. For a moment, I feared that the shift kit might have made things too harsh. But when I thought about it a little more, I figured that I was probably just feeling the lack of rolling resistance that would help dampen the “shock” of each shift once the wheels were back on the ground. And/Or maybe it would just disappear as the calibration fine-tuned things?
Another cause for concern was when the ABS and brake warning lamps soon lit up. I crossed my fingers and hoped that it was just picking up an inconsistency between the spinning front wheels and the stationary rear ones...
I noticed that once I lifted the accelerator at 50 mph and started coasting, it developed a tendency to settle down to about 30, and just stay there. The first few times it did this, I used the brakes to help bring it down, even though I wasn’t supposed to apply them until 20 mph. But I soon realized that turning on the HVAC blowers seemed to induce enough of a load to help pull the speed down without touching the brakes.
It took over an hour to complete the “quick learn”. After repeated mid-air acceleration, coasting, and braking cycles, a test drive was in order. Towards the end of the calibration, I thought that the shifts felt maybe slightly smoother than when I had started (or perhaps I was just unconsciously compensating as I developed a better feel for the pedal?).
But now with all four wheels on pavement, the shifts were buttery smooth. I took it up to highway speed and back down again several times, and the transmission performed flawlessly. Nothing particularly interesting (it is a Town & Caravan, after all), but the shifts were smooth, and there was no need for further “re-scheduling”.
Unfortunately, the ABS & brake warning lamps were still on, so I parked and shut the engine off for a moment. When I restarted the vehicle, they turned themselves off. Another quick test drive confirmed that everything was as it should be, and I could finally return the vehicle to its owner. Yusss!
"benjrblant" (benjblant)
04/13/2017 at 18:03, STARS: 2
dedication! It’s made for some good afternoon reads! thanks for sharing.
"Textured Soy Protein" (texturedsoyprotein)
04/13/2017 at 18:28, STARS: 1
My mom had a ’96 Town & Country that apparently had this transmission. Actually three of them because they kept dying. The second and third were Jasper rebuilds, the third was a free warranty replacement of the second.
I remember all three of them liked to make this rattle noise every time it shifted.
"Urambo Tauro" (urambotauro)
04/13/2017 at 18:45, STARS: 0
Yikes! I wonder what cased that. I’ve heard that earlier models had a tendency to break snap-rings.
"Textured Soy Protein" (texturedsoyprotein)
04/13/2017 at 19:27, STARS: 0
I had a WJ Grand Cherokee beater that made the same noise. Back in the 90s I often heard Chrysler products make it. I just thought of it as the usual shift noise. Mostly at like parking lot speeds. It wasn’t loud.