[Ed B]

99 GC, remanufactured transmission installed 6K miles ago, 3.8 engine, 240K total miles.
Daughter's van has been well maintaned and is in overall good condition.
But, since the tansmission installation, she has had new problems which seem to be related directly to the transmission.

1. While accelerating normally from a stop there is a jerking in the powertrain. She described the jerking as intervals of jerks, one after another. This has happened three times, two of them were rough enough to shake the entire vehicle so that everyone (4 persons once, 7 next) was well aware of a problem. The third one (most recent, driver alone) was less violent but very clearly the same sort as the other two.

2. From a parked position and trying to go into reverse, the transmission doesn't seem to engage making the driver think either something is behind the van and preventing movement or the shift selector wasn't properly engaged.

3. On open road while ascending a hill, downshift seems to over react and results in excessive rpm (4000+) with reducing mph. I asked if the incline was steep enough that the van should not have been able to accelerate going up. She said it wasn't that steep and that the situation was very definitely abnormal.

My daughter is responsible for most of these miles and is more familiar with automobiles than the average person. I will have the van sometime tomorrow and may know more after a test drive.

Your help is sincerely desired and will be greatly appreciated.

Thanks, Ed B

 

[ImperialCrown]

Fluid level and condition OK? Is it still under a warranty?
You might have fault codes stored in the TCM that won't light the 'ck eng' light and will require an advanced scan tool for reading those transaxle codes and further tests and diagnosis.
Jerking might also be an engine misfire, but could be clutches slipping and the other issues do sound transaxle related.

 

[Doug D]

Has anyone verified the proper fluid (ATF+4) was used?

 

[chuzz]

I'm with Doug on this one. Who did the rebuild and what fluid did they use? Was the torque converter replaced too or did they use the old one? If it had trash in it from the transmission, then it could have contaminated the new fluid. Did she get a warranty with the rebuild? If so, take it back and get some answers to these questions.

 

[John Wood]

Pay attention to the loss of power going uphill. One possibility may be the start of a clogging catylic converter. I had this situation and it acted similar, with pre-mature downshifting on inclines, but a sudden reduction in power. Pushing the throttle more did not provide an increase in engine power on the uphills. Ultimately the engine just bogged down.

 

[Ed B]

Plan has changed but I did get more information.
1. Fluid level ok, but not sure if ATF+4 grade at present, investigating..
2. Rebuilt by a local independent transmission shop, does have a warranty unknown terms at present.
3. No info yet whether the torque converter was replaced, investigating.
4. Will check out the catalytic converter idea.
5. Probably the most significant of all - explanation below.

After the rebuild my son in law discovered the odometer didn't agree with a measured mile marked on the highway. Upon further checking it was discovered that the repair shop hadn't been able to enter the exact tire size into the TCM. The repair shop said the inability was due to the software they use. The shop agreed to take the van to a Dodge dealer and have them adjust the setting. I think my daughter said they referred to "pinion reset". For some reason, unknown as of now, the dealer's shop didn't or couldn't do the adjusting either. The dealer reportedly told the independent shop that the owner would need to bring the van to to the dealer's shop to have the adjustment done. The van is at the independent repair shop now and they are supposed to be trying to do the proper adjustment to the TCM. I am told the shop is trying to "get to the bottom of" the inability to adjust the TCM properly.

I think the problems will be solved when someone makes the correct adjustment to the TCM. Does this seem likely?

Is it possible that a wrong part was installed during the rebuild and altered a ratio enough to throw the odometer off? Would this cause the needed TCM adjustment to be outside the range of the available settings using their software?

Please excuse my crude attempt to properly describe things, maybe it will make sense to you.

 

[valiant67]

No, the TCM won't account for those problems except possibly #3. There is something mechanically wrong for #1 and #2 in the original post to be happening most likely.

 

[Ed B]

I have one other bit of information:

The torque converter was replaced during the rebuild, so unless the new one is defective this eliminates one possible cause of trouble.

I appreciate all who have been trying to help me, Allpar people are fantastic!

 

[chuzz]

I wonder why the dealership wouldn't or couldn't try a reset? Does the actual owner have to be there with proof of ownership and identification for that?

 

[Ed B]

The transmission repair shop has advised my daughter to replace the TCM and offered to install it without a labor charge. She is driving the van with the old TCM in place now.

Since the problems are intermittent, it remains to be seen whether or not some of the trouble may be eliminated as the controls relearn and adjust in response to her driving.

Based on the input from Allpar posters, I doubt that the TCM will solve all the problems. Especially the jerking during takeoff and the erratic reverse gear engagement.

Although I don't have the ultimate solution yet, I probably should mark the thread solved. Trouble is I'm not familar with the forum etiquette in that regard. What is customary?
I'll follow your guidance.

Thanks, Ed B

 

[valiant67]

I would not mark it as solved because it is highly unlikely the TCM will correct this.
I think there are internal transmission issues that mean the shop will be tearing into it again. For now, they are grasping at straws to avoid that it appears.

 

[B10alia]

The shuddering sounds like the TCC to me. Isn't there a break-in procedure for the clutch?

The 41TE is a descendant of the A604 Ultradrive transmission that Chrysler had so many problems with back in the early '90s. There are only so many adjustments that can be done, since the transmission has a rather advanced control unit that self-adjusts over time. However, pinion factor is one of these initial settings. Basically, the transmission is told how many pulses from its speed sensors correspond to one wheel rotation and how far the wheel travels when it rotates.

I'm not surprised at all that the trans shop can't access the TCM to reprogram it. The interface is OBD-II, as federally required, but a generic OBD-II box, and probably even the top-of-the-line ones, will only be able to give a general picture of the transmission. A Chrysler DRB-IV tool, costing many thousands of dollars, is probably necessary to acces the TCM to set the pinion factor and put the computer into TCC break-in mode. There's a cycle that transmission controller is supposed to run to properly break in the clutch.

It sounds to me like you have one problem that's directly computer related, one that may be computer related and may be able to be fixed by playing with the computer, and one that could be mechanical, either internal or external. Do the back-up lights come on when the vehicle is put in reverse?

The reason the reverse issue could be so serious is because that could indicate a hydraulic transmission issue. When the solenoid valves in the transmission are at rest, there are only two possible gears that can be used-- second and reverse. If the transmission fails electronically, the solenoid valves revert to second and reverse gears only by default. Since the transmission can operate in these two gears with the electronics effectively out of the loop, a failure of either second or reverse tends not to be electronic in nature.

 

[Ed B]

At last, the transmission is operating normally.

Tyhe new TCM didn't correct either of the issues, so the old one was put back on.
All the erratic shifting and jerking required one external adjustment followed by internal repairs - which included replacing one item that was installed during the initial rebuild (unsure what it was).

The correction of the pinion factor was done by the dealers service department. It turned out that the tires were the identical size that is listed in the specifications label on the door jamb. The independent repair shop still couldn't correct the pinion factor even though they had upgraded the software they used.

So now it appears that all the problems have been corrected and we are thankful.

Speaking of 'thankful' - Thanks to all of you for each of your replies & thanks to Allpar for this forum!

This issue is Resolved!

Edit: Don't know why 'BEST ANSWER' shows on this post. I certainly didn't deserve this, actually all the accolades should be given to every poster in this thread except me!