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Hepl me diagnose my transmission issues:
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=69397		 Page 1 of 1
Author:  Sir Sam [ Fri Jun 29, 2012 6:31 pm ]
Post subject:  Hepl me diagnose my transmission issues:
I've been scratching my head on this one awhile now and haven't really been able to figure anything out.

In december of 2009 I replaced the transmission with a used one that was supposed to have 30k on it. It was pretty greasy/dirty so I'm not sure I believe that. My previous tranny just got overheated cooked, I don't know how it happened, I wasn't driving it, all I know is that it got bad and quick. By the time I got to it it was just toast, completely burnt up, melted sensors, etc, it got HOT. Fluid black as night, smelled terrible, etc.

This was at 83k miles, new filters and updated torque converter were installed at this time. New filters were also installed back in the fall.

50k miles later on this other transmission I am having other problems. No DTC's are present.

It feels like I have a bit of the tranny drainback issue. Not a problem if I rev it up in neutral for a bit before getting going. That being said, I have other symptoms that are concerning.

The 2-3 shift that occurs at about 35mph is very clunky and slow. It almost feels like someone presses on the brakes during the shift because you are sort of pulled forward. The 1-2 shift is also a little clunky but not nearly so bad.

Sometimes when getting on the throttle hard from a full stop (like at a light) I will get a "slip-catch-slip-catch-slip-catch" at about 2500 RPM that happens in for about a total of one second. Imagine saying something like "slip, slip, slip" fast enough to say it in one second, and thats about what its like.

However the rough 2-3 shift and other issues don't feel so apparent when the "OD off" button is selected, mostly because at 35 mph is not down shifting into the next gear.

I'm trying to watch line pressures to see if there is anything I can tell about it that way. The FSM lists line pressure as follows:

1st 135 PSI
2nd 120 PSI
2nd Prime 120PSI
3rd 120 PSI
4th 120 PSI
Neutral 120 PSI
Reverse 220 PSI

Its hard to test 2-4, but 1st, reverse, and neutral are easy.

In 1st, at idle, with my foot on the brake my line pressure is 85 psi, if I rev it up just a little the line pressure comes up to 135 and stays there.

In Neutral at idle the the line pressure is 100, at 1000 rpm it increases to 120psi.

In Reverse at idle the line pressure is 85 psi, to 220 at 1700 rpm.

With the shift lever in 2nd at idle the pressure is 75 psi to 135 at 1600 rpm.

While these are lower than the stated values they do come up to the state values and then hold. I do not know if my line pressure readings are lower than they should be at idle or if these numbers are fine. I hope to compare to another CRD and see.

Any thoughts for me?
Author:  Glend [ Fri Jun 29, 2012 6:41 pm ]
Post subject:  Re: Hepl me diagnose my transmission issues:
Before assuming the worse (internal inssues) I would disconnect the battery for awhile to reset the TCM and ECM, then when reconnected the transmission will go into Learn mode. Drive it easily for a few hours and it will reset all the clutch volume indices. Check the fluid level obviously.

The slip slip feeling could be the clutch pack, but when does it happen? The lockup clutch material is on the back side of the torque converter and if you over-torque the flywheel mounting bolts you can dimple the clutch surface on the inside of the shell and produce that sort of effect (this was discussed by GDE in their instructions on replacing the TC).
Author:  Sir Sam [ Fri Jun 29, 2012 6:56 pm ]
Post subject:  Re: Hepl me diagnose my transmission issues:
Glend wrote:
Before assuming the worse (internal inssues) I would disconnect the battery for awhile to reset the TCM and ECM, then when reconnected the transmission will go into Learn mode. Drive it easily for a few hours and it will reset all the clutch volume indices. Check the fluid level obviously.

The slip slip feeling could be the clutch pack, but when does it happen? The lockup clutch material is on the back side of the torque converter and if you over-torque the flywheel mounting bolts you can dimple the clutch surface on the inside of the shell and produce that sort of effect (this was discussed by GDE in their instructions on replacing the TC).


At about 2500 to 2700 rpm it starts when on heavy throttle from a stop. I guess this means 1st gear. It does not happen consistently.

I have been debating doing a quicklearn via the DRBIII to reset the clutch volume indices.

I don't see why over torquing the bolts would cause that problem now and not 50k+ miles ago.

Might be time to try a relearn procedure.
Author:  tjkj2002 [ Fri Jun 29, 2012 9:21 pm ]
Post subject:  Re: Hepl me diagnose my transmission issues:
Where did you buy the filters from?

There is a known issue with the spin on filters and the dealer has the newest updated versions,aftermarket does not.
Author:  Sir Sam [ Sat Jun 30, 2012 12:15 am ]
Post subject:  Re: Hepl me diagnose my transmission issues:
tjkj2002 wrote:
Where did you buy the filters from?

There is a known issue with the spin on filters and the dealer has the newest updated versions,aftermarket does not.


Dealership both times for the filter set. However my drainback issues became more obvious after replacing them back in the fall. Drainback issues do not seem to be the cause of this.



Update, did a quicklearn via the DRBIII and took it for a drive, shifting and drive behavior was noticeable different from this afternoon. Took it for a vigorous romp and it seemed to do pretty well. However it was pretty hot eariler in the day and had cooled off to upper 80s by the time I did the quicklearn, I'm not sure if the heat was a factor.
Author:  nissanfrontier [ Sat Jun 30, 2012 12:18 pm ]
Post subject:  Re: Hepl me diagnose my transmission issues:
Maybe the fill on dip is not correct! I had heck of time getting proper amount of fluid in jeep. If jeep Dealerships can not do it correct why would we be any different. I ended up adding 7quarts ATF-4 doing filter change. Whole checking level makes more sense now. With motor turned on and in park quite few quarts are pumped through tranny at with cold motor/tranny the lower cold fill mark is used. When it warms up fluid after driving awhile hot side fluid comes into play. Guess clutches and such squeeze out some fluid and it goes into pan. Now I find with 7quarts low cold is fine but high side when warm is still under hash marks. I let it be at 7quarts because the factory dip stick can not be accurate.
Author:  Sir Sam [ Sat Jun 30, 2012 11:03 pm ]
Post subject:  Re: Hepl me diagnose my transmission issues:
I did add a half quart and took it for another drive, it seems like its a little better now. Will drive for a few days and report back on how it is doing.
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