Can I "Teach" Auto Trans When To Shift?

[noparking]

2007 Liberty 12,000 miles
When accelerating slowly from stop, such as in mall parking lot, auto transmission makes a CLUNK noise when it shifts into 2nd. Happens at about 13-14 mph speed. When accelerating at normal speed, such as after making a right turn at a light, transmission shifts very smooth. To avoid the CLUNK when maneuvering in parking lots, etc. I have to play uncomfortable game of accelerating enough to shift, then brake. Not a new problem. Just tired of it.

Is it possible to "teach" the transmission to shift from 1st to 2nd at lower speed such as 11-12 mph? Physical adjustment to trans or electronic control?

Thank you for any suggestions

 

[tjkj2002]

Pretty normal operation for the 42RLE.

 

[WickedBruce]

Mine never clunks!

 

[noparking]

Thank you for the comments. I am visiting dealer by Friday... unrelated service. Will ask them the question, but they are not great at diagnosis. Will post the result.

 

[osufans]

yeah, mine never clunks when upshifting. it's a known problem when decelerating for there to be a "bump-shift" feel when dropping from either 3-2, or 2-1, can't recall at the moment...but it's not a known issue to feel it when upshifting. i'd get it checked out.

 

[dude1116]

I say, if you're not getting codes, don't worry about it too much. You have two options with ****** problems anyway: rebuild or replace. Both are expensive, and both don't really matter HOW warped the clutch packs are. You SHOULD be concerned when/if it starts slipping, so you don't strip the gears.

 

[eradicator006]

I have the exact same thing with my 2005. I get the clunk when accelerating VERY slowly and it shifts in to 2nd. I also sometimes get the same clunk if I give it too much gas too quickly when taking off from a stop. I have also gotten the clunk when coasting from a high speed to a slow speed and the transmission down shifts (i think from 2nd to 1st).

I've never been to the dealer about it but I have done a lot of research online. I don't think it is any thing to worry about. In my case the clunk isn't horrible sounding. It sounds like something in the transmission is playing catch up.

 

[lautinjr]

is there any transfer case or trans mounts that might be going out and causing this.

 

[noparking]

Trans Shift Noise Fixed

Thank you for the comments. I am visiting dealer by Friday... unrelated service. Will ask them the question, but they are not great at diagnosis. Will post the result.

Visited dealer today. Asst Service Mgr, who has also been a tech, stated that auto trans shifting is all regulated digitally. They checked for any software updates. Were none, so they started a “forced reset” (or similar terminology). As I drive, it will adjust to my driving habits. It immediately took care of the “clunking” noise and shifts sooner from 1st to 2nd. It is much more relaxing to drive with the shift point just a bit slower than the previous one. Hope this is useful info. I appreciate the comments that have been posted... this has to be the best Jeep forum I have found!

 

[HoosierJeeper]

Mine does it a bit. Doesn't bother me. When I had my fluid changed and the trans was re learning, it learned with a 3.5k trailer behind it.

 

[dude1116]

Glad to hear you got her reset Mine still does it since my flush. Usually when I'm doing a rolling stop, then hit the gas at a low speed. I think it's about to switch from 2 to 1, but then shifts to stay in 2, causing the clunk, but who the hell knows?

 

[surfRenegade]

Mine does this some times when I get on the gas hard from a stop. How did you do this "reset"?

 

[Ry' N Jen]

We just had a rebuilt ****** installed into our 2004 KJ and it does the exact same thing!
It's the transmission...

 

[JeepJeepster]

May be wrong but I always figured it was the slack in the drive-line splines. Transmission makes a little slack when shifting so the splines 'clunk'.

 

[leadfoot]

Visited dealer today. Asst Service Mgr, who has also been a tech, stated that auto trans shifting is all regulated digitally. They checked for any software updates. Were none, so they started a “forced reset” (or similar terminology). As I drive, it will adjust to my driving habits. It immediately took care of the “clunking” noise and shifts sooner from 1st to 2nd. It is much more relaxing to drive with the shift point just a bit slower than the previous one. Hope this is useful info. I appreciate the comments that have been posted... this has to be the best Jeep forum I have found!

I have searched the forum using the term "forced reset" and the only result returned was this thread.

What is involved in doing this procedure?

What is the "correct" terminology when referring to V6 KJ's using a "42RLE" (rectangular pan gasket/filter).

 

[noparking]

Since I started this, I did a couple searches to see what is out there. Transmission Relearn may be better term. I found several items that could be useful as places to start.

First is the link to a document I found re: electronic controls for transmission shared by Liberty, Grand Cherokee and other Chrysler models. This is for 2002 models. Transmission ID info in document
http://img97.imageshack.us/img97/2776/45rfe545rfe.pdf

This is another link to some posts in this forum from 2009.
7-06-2009 by tjkj2002
http://www.jeepkj.com/forum/f196/transmission-fluid-change-39720/

Hope these are good clues for tracking down some useful information