kishy's 1991 Plymouth Acclaim

[kishy]

Alrighty, picking this up again...

I found some guy on eBay selling a Timken bearing kit for the A604. The kit outer bag was torn open, but the bearings were sealed, and the kit bag appeared to contain most of two kits instead of just one. That's how I solved that problem, plus extras for next time. insert nervous laughter here



I did buy some LubeGard Blue Assemblee Goo, a tacky assembly lube recommended by one of the folks on Allpar. This stuff is awesome and really helped with "gluing" parts together so they stay in position during assembly. It's specifically designed to be compatible with ATF and melt out into the fluid after assembly.

While I was slapping all the thrust bearings in, I found two things of note.
There is a thrust bearing trapped inside a planetary set, which cannot be replaced as the shafts for the planet gears in that set are welded in place. I'm guessing this is a rebuilder fix for a specific problem or to prevent a common comeback - regardless, bearing wasn't able to be changed, but it rolled smoothly by hand so no concerns there.



I also found that the sun gear in the rear planetary set had two broken teeth. I found no evidence of these teeth being elsewhere in the unit, but if they were pulverized into a fine dust, it'd be hard to find them. I went back and forth in my head about if I should do anything about that, reasoning that perhaps the gear was like this before it was last rebuilt and the rebuilder decided to leave it. But then I bought one on eBay for 20 bucks and put that in, instead. Learning that the 41TE is the basis for the 62TE (when learning that this part is common between them) didn't surprise me at all. At work we have a fleet of 3.6/62TE minivans, and the transmission behaviour between those and this car is shockingly alike. If you told me there was 90s-era 41TE TCM code running in the modern PCMs driving 62TEs I would totally believe that.



When I moved on to reassembling the wizard magic device - the clutches - I found more self-inflicted problems. I completely mangled a couple clutch discs on that first re-assembly attempt, due to alignment problems during reassembly. It sounds like this is a common mistake, but that didn't make me feel better about it. I bought a set of clutches and used the new ones for every spot that I had disassembled to that point (everything in that drum). I did not tear the unit down further because, between healthy CVIs (TCM tracks and can report inferred clutch wear, known as Clutch Volume Index) and the condition of all the frictions I could touch, and the lack of wanting to break more things, it just didn't make any sense to tear down any further at that point.

I referenced both of the following during the reassembly and I strongly recommend these resources to anyone who wants mess around with this stuff.

1. ATRA's "plain English" rebuilding procedures for the 41TE aka "41TEBook.doc"
2. Southern Illinois University's video documenting the overhaul of a newer variant of the 41TE, in a classroom setting, oriented towards students in a trade school

The unit went back together correctly this time.

Removed transfer gear cover to unbend it (don't let the unit sit on it like I did). Unbent the cover and reinstalled.
Mated reman converter with transmission. Took a little manipulating but finally got it to drop down where it belongs.
Installed new output shaft seals.
Replaced rear main seal. Crank is grooved so this may leak again, but it was just a little wet, not really leaky-leaky, so I'm optimistic.
Reinstalled transmission in chassis.
Dropped the pan (again; had reinstalled it to protect valve body during manhandling), replaced the filter. Found previous filter o-ring was torn. Installed new pan equipped with drain plug. Transferred pan magnet from old pan to new. Used only the clean rubber gasket included in the filter kit, no RTV or sealants, we'll see if I have any regrets soon I'm sure. Being a new pan it's nice and straight so probably fine.











Air-checked the in-radiator transmission cooler. Found no obstruction. Installed auxiliary cooler in series after the in-radiator cooler. Had only 3/8" hose on-hand, the fittings seemed closer to 5/16, once again we'll see if I have any regrets soon I'm sure. Picked an unusual way of mounting the aux cooler: drilled 4 holes in the support in front of the condenser and used the included-with-cooler round zip tie strip things to stick it onto that support, with foam pads standing it off of the support. Seems like it'll work well enough.



Replaced TCM with the one purchased on eBay with the newest available programming.



Reassembled the cooling system. Finished bolting together trans and engine. Reinstalled starter and front engine mount. Reinstalled CV axles and reassembled front suspension. Filled transmission with fluid.



Test drive found that I have all of my gears, and I have functional converter lockup!
No codes after about 45km of drive time in mixed conditions.
No fluid leakage parked overnight. The concerns I sought to address appear to be resolved.







There was a temporary condition for the first few shifts from P/R/N to a forward drive gear, which was a loud bang noise at gear engagement. It isn't happening anymore and the unit remains quiet and well-behaved.

I do believe a couple items require further attention:

• The TCM reports the shift lever position on my scan tool. It is possible to position the shifter "in a gear" but have the TCM report just a blank space. The switches that sense shift lever position may require cleaning or replacement.
• With the converter locked, engine RPM and turbine RPM are supposed to be approximately identical (due to lockup). However, turbine RPM reports a little lower. Since it isn't setting a code, it probably is not slipping, which means there's a sensor or sensor circuit problem for the turbine speed sensor.
• With the new TCM, the scan tool does not show the status of the brake pedal but the old one did. I haven't replaced the brake light switch yet, no changes in that area. Not sure what's up with that. The brake light switch is already being changed because I feel the brake lights should turn on with less pedal effort than I am experiencing.

Aside from those concerns, I think the transmission topics I sought to solve here are sorted out. This was my first time inside an automatic. Mistakes were made and lessons were learned, but I'm not at all afraid of tearing into another sometime. The list of things I can't/haven't done myself grows shorter and shorter - basically now being limited to engine rebuild, setting up rear end gears, and proper body work.

[Tiggie]

Glad this took a turn to the better!

[kishy]

Syncing this thread up with the one on Allpar:

Found this while out and about. It's a LeBaron, but a little short on options vs my lowly Acclaim which is nearly fully loaded.



The car has been driven a reasonable distance since the trans went back together. Probably around 300km now.
Within 100km, a fault did become apparent. Lockup stopped occurring (and TCM stopped attempting to do it) and code 38 is set. Code 38, in my understanding, basically means the TCM didn't like its observations about how the converter clutch engaged, and the TCM aborted using lockup as a result. The TCM will not make any further attempt to do lockup until the code is cleared.

From testing, I clear the code, I drive in conditions that should get lockup, partial lockup is attempted, and is then aborted and the code sets immediately. There is a hard fault preventing it working correctly. I checked fluid pressure on that circuit and found the pressure substantially below spec - there is a fair chance that somewhere, fluid pressure is being hemorrhaged through something that is worn past its tolerance. The unit is well-behaved except for lockup not working, so I think this is probably where I leave it alone. Like I said before I even started with the transmission: if the only fault had been lockup not working, I would have left it alone. I only dug into it because of the catastrophic fluid loss.

Summarizing the work done to the transmission:

• Replaced most thrust bearings with new
• Replaced underdrive, overdrive, and reverse clutch frictions with new (did not touch 2-4, or Low-Reverse)
• Installed "case savers" to retain the diff pin in case of roll pin failure
• Replaced damaged sun gear from rear planetary set with used
• Replaced torque converter with newly purchased reman part
• Replaced transmission filter and installed new pan with drain plug
• Replaced 4672002A TCM with newest available 4796121 TCM, used
• Filled unit with fresh Mopar ATF+4
• Installed auxiliary transmission cooler

All of that resulted from "might as well, I'm here anyway" type thinking while trying to solve the fluid loss issue. Plenty of it resulted from complications I ran into due to basically not knowing what I was doing, as well as discoveries of "might as wells" along the way. Oops. I'm pleased that I was successful in that original goal.

I did investigate the shift cable adjustment because of some weirdness my scan tool was revealing, e.g. lever being "seemingly in a gear" but TCM thinking the gear was a different one, or was an implausible value (blank space or question mark indicated on the scan tool instead of, for example, OD). I was unsuccessful in adjusting the cable to be any better. I then replaced both the PRNODL and NSS switches - the pair of which are used in combination by the TCM to identify which position the shifter is in - and it seems to have become very slightly more accurate since doing that. There was some evidence that the switches previously on the unit were older design parts which had been superseded to fix this type of accuracy issue.

Other developments:

The front brake flex hoses have been replaced with new, in pursuit of a mild brake drag problem. Somewhere between the hoses and manually pushing back the calipers seems to have fixed it. The left rear flex hose has been replaced with new. The tube nuts for that one would not turn, which destroyed the (100% perfect, flawless) factory original brake line. I had to make up a new line for back there and I was sour about it. I have a new flex hose for the right rear but have held off on touching it. The rear wheel bearings (which are like the Box Panther fronts - inner and outer tapered adjustable bearings) have been repacked. There is brake fluid loss at the master cylinder, so that's going to need to be changed. It's a very slow leak but it is definitely wetting the front of the booster and I'd be surprised if the booster isn't full of fluid as well. All brake fluid has been replaced with fresh.

The front lower ball joints (the only ones it has) have been replaced with new. The outer tie rod ends have been replaced with new. The inners are coming soon, when I feel motivated. They look like an absolute bear to do on this car, but we'll see. Alignment was off before I started and feels to be about the same now still. The tires need to be replaced due to age so I'm not concerned about wearing them in the meantime.

There is an occasional squeak noise from the rear suspension. I cannot find the source of it. Current belief is that it's one of the axle bushings allowing metal-on-metal contact in specific scenarios. But the bushings look great overall and everything is positioned what seems to be correctly.

The speedometer reads pretty much exactly 10kmh fast, which leads to driving slower than intended. This is annoying. The speedometer is electronically fed (like 90+ Panther), not cable-driven. The digital trip odometer on the Traveler (like Ford Tripminder) is GPS-accurate, so the speedometer issue appears to be a fault within the speedometer itself. As noted before, the mechanical odometer and trip odometer are inoperative. These are mechanically driven by the electronically-fed speedometer, so all of these faults originate inside the speedometer itself. I'm trying to track down a whole cluster for parts-swapping purposes to trace the problem further. It isn't an assembly that's friendly to being taken apart.

As I mentioned previously, the brake lights weren't turning on until I was applying more pressure to the pedal than I prefer. I had purchased a new switch but upon reviewing the Haynes manual, discovered that the switch is adjustable in how it is mounted. I pulled the switch out and verified it works correctly in my hand. I then put it back in and allowed it to "self adjust" as per the Haynes book, and it's now perfect. If I push the pedal at all, enough to move it but not enough to begin operating any brakes, the lights come on.

I was out driving the car in the rain the other day. The wipers quit on me. Seems the switch makes bad contact since beating it up a little helped bring them back, I think. Dirty contacts perhaps.

The car had functioning DRLs, but they seem to have stopped working with the replacement of the TCM. I haven't checked the manual/diagrams to figure out the relation yet. DRL behaviour was previously that what appeared to be the low beams at reduced output would light up after the car moved a certain number of feet in either direction. After they turned on, they remained on until the ignition was turned off. I'm generally a supporter of DRLs but I am not prioritizing fixing this, if for no other reason than them being functional makes it impossible to drive around at near-dusk with parking lights only, which is an aesthetic preference of mine at some times.

Someone pointed out something to me: the wheels on the car are PT Cruiser wheels. Chrysler OEM stuff. I figured they were aftermarket.

Perhaps to nobody's surprise, I am not particularly in love with the Acclaim. It is a spacious, comfortable, well-optioned car. It has plenty of power and is responsive to drive. I like how it looks. On paper, it should be a slam dunk, but in reality it's just not really speaking to me. I will continue chipping away at its needs, but most likely I will end up selling it sometime next year. If nothing else, it's been a valuable exercise in testing my interest in the box Panthers. I don't think I'll be parting ways with those any time soon.

[gadget73]

did you replace the seals on the input shaft when you had it apart? From assembly pics I've seen of transmissions and from the steering racks I've messed with which use similar seals, it seems like it uses those to get fluid to and from the various clutches and up into the converter lockup clutch. Its those barely-flexible plastic things that have to be stretched into position and its a real SOB to do without damage. if one of those is not sealing correctly it may just be blowing fluid out around it and dumping back into the case. If there is a seal at the very end of the shaft where it goes into the torque converter a leak there would do the same thing.

[kishy]

did you replace the seals on the input shaft when you had it apart? From assembly pics I've seen of transmissions and from the steering racks I've messed with which use similar seals, it seems like it uses those to get fluid to and from the various clutches and up into the converter lockup clutch. Its those barely-flexible plastic things that have to be stretched into position and its a real SOB to do without damage. if one of those is not sealing correctly it may just be blowing fluid out around it and dumping back into the case. If there is a seal at the very end of the shaft where it goes into the torque converter a leak there would do the same thing.

The sealing rings - which I believe are actually aluminum? - were not replaced. Indeed, it is entirely possible that there's cross-bleeding happening. This is one of the many parts that I touched which I probably should have changed, but did not.

Where it's sort of mysterious is this: my understanding is that the converter clutch is normally applied, and fluid pressure is used to release it. It's normal to see 90ish psi on the "lockup off" test port, when the clutch is not applied. When it is applied, you're supposed to see under 10 psi (e.g. we dropped the pressure therefore the clutch applied). It's bizarre to me that a low pressure condition could cause a failure in applying the clutch, and it's not clear that I've come to the right conclusion about it. It's entirely possible the low pressure condition is unrelated and something else has happened - for example, this condition may have happened and destroyed the reman converter: https://atracom.blob.core.windows.ne...aug/atb429.pdf

I'm quite interested in seeing the problem through to resolution but I'm also not really interested in taking the trans out again, so I think it just sits for now. Drive it a little here and there, see what sort of motivation I've got in the future.

[gadget73]

pressure to disengage seems odd but maybe. I guess it must have a spring in there to engage the clutch and a piston that pushes it open, sort of like a pressure plate on a manual transmission. If thats the case I agree it seems odd that leakage would cause a failure to engage.