42RLE just started sloppy shift from 3rd to 4th

Stockli

TJ Enthusiast
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Jun 12, 2016
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Fort Collins,CO
So my 03 just started sloppy shifting from 3–4.

it gets hung up, and revs slightly higher before getting it into 4th.

I recently changed out the TPS as I was getting g the voltage too high p0123, and upon pulling the tps I noticed the old sensor was a little crunchy. the replacement is a Mopar TPS and that issue is gone now.

it really only does it when casually driving and not when I am into the accelerator hard. Under hard acceleration it shift normally. It also shifts normally with OD off

my fluid level is good and the fluid is clean and clear, no real burnt smell I can notice.

the trans has 135k on it. Am I in for a rebuild soon? PCM still mapping with the new sensor? I just changed the sensor about 2 weeks ago I have drive. It less than 150 miles.

decent shops in Greeley/ft Collins areas?

i understand the 42rle is electronically monitors and will tell me when it’s not well, no codes to be read at all.
 
Yeah, I will get a vid next time I drive it, it’s quick and you can hear the rpm’s pick up not sure if you can see it in the tack.
 
I have a similar issue but it happens while shifting 1st to 2nd. I think you did a better job of describing it. I posted a thread about the same time I replaced my IAC. The issue has only happened about 10% as frequently as it used to. I don't understand how they could be related. I didn't get a great video of it but I did get it to happen... > https://wranglertjforum.com/threads...der-shifting-into-2nd-gear.63537/post-1150953
 
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I have a similar issue but it happens while shifting 1st to 2nd. I think you did a better job of describing it. I posted a thread about the same time I replaced my IAC. The issue has only happened about 10% as frequently as it used to. I don't understand how they could be related. I didn't get a great video of it but I did get it to happen... > https://wranglertjforum.com/threads...der-shifting-into-2nd-gear.63537/post-1150953

....and then you never followed up.

Definitely want to see a good video of what you're both describing.
 
....and then you never followed up.

Definitely want to see a good video of what you're both describing.

I’ll try and grab one when I drive it again.
It feels like a TCM module issue, but no codes

It’s almost as if it just doesn’t get enough pressure to upshift and briefly hangs in neutral. I’d call it a very soft shift from 3-4, as if you had a little clutch slip with a manual trans
 
Do you have any issues whatsoever with it going into 2nd? 2nd & 4th gears use the same 2/4 holding clutch so If it was a clutch or piston apply problem there I would expect similar behavior in the 1-2 shift. If 3rd gear works fine I would not suspect the overdrive clutch, which already applied when it goes to shift into 4th.

I don't know enough about the various solenoids to do any sort of troubleshooting there.



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Do you have any issues whatsoever with it going into 2nd? 2nd & 4th gears use the same 2/4 holding clutch so If it was a clutch or piston apply problem there I would expect similar behavior in the 1-2 shift. If 3rd gear works fine I would not suspect the overdrive clutch, which already applied when it goes to shift into 4th.

I don't know enough about the various solenoids to do any sort of troubleshooting there.



View attachment 349361

No, never an issue going into 2, occasionally it does some goofy stuff in 1. It has done this since new and I figure it’s just a “feature” of this trans.

oddly I did have some issue shifting it into 4 low this summer. As I put it the trans in N, the T case didn’t want to shift from N to low, as if the trans was rotating. Similar to if the synchs are worn on a manual and you don’t time a shift right. I never had that before. It happened a few times this summer.
 
No, never an issue going into 2, occasionally it does some goofy stuff in 1. It has done this since new and I figure it’s just a “feature” of this trans.

oddly I did have some issue shifting it into 4 low this summer. As I put it the trans in N, the T case didn’t want to shift from N to low, as if the trans was rotating. Similar to if the synchs are worn on a manual and you don’t time a shift right. I never had that before. It happened a few times this summer.

There's no synchro on 4L, although you do need to basically be stopped to get it into 4L.

What goofy stuff in 1? Manual 1 or Drive 1?
 
There's no synchro on 4L, although you do need to basically be stopped to get it into 4L.

What goofy stuff in 1? Manual 1 or Drive 1?

Yep I was stopped. Completely, both T case and Trans were in neutral

sometimes in one it will feel like it’s no fully in gear, and then bumps fully into gear as rpm increases a bit
 
Yep I was stopped. Completely, both T case and Trans were in neutral

sometimes in one it will feel like it’s no fully in gear, and then bumps fully into gear as rpm increases a bit

That feels like a pressure thing, or possibly a worn clutch thing. When was the last time you drained the fluid and/or actually looked in the pan? I've never so much as looked at the 42RLE so I'm really just guessing along with you, but I'm happy to play along and try to help.
 
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That feels like a pressure thing, or possibly a worn clutch thing. When was the last time you drained the fluid and/or actually looked in the pan? I've never so much as looked at the 42RLE so I'm really just guessing along with you, but I'm happy to play along and try to help.

Haha yeah me too.

about 5 years ago the filter and fluid was replaced. I have not personally dropped the pan on this one, or drained/refilled. The fluid looks good right now, but I Pam in the process of changing everything else so I am not opposed to changing it if need be
 
Here you go it happens twice in this short clip. Can be heard and seen on the tach. Once about 14 seconds in and the other much more clearly later on
 
Haha yeah me too.

about 5 years ago the filter and fluid was replaced. I have not personally dropped the pan on this one, or drained/refilled. The fluid looks good right now, but I Pam in the process of changing everything else so I am not opposed to changing it if need be

I would say it's time. I guess it's coming back clean off the dipstick is how you're saying it's clean? At 5 years I'd say you got your money's worth on the fluid. Drain the fluid, drop the pan, let's see what you've got.
 
I would say it's time. I guess it's coming back clean off the dipstick is how you're saying it's clean? At 5 years I'd say you got your money's worth on the fluid. Drain the fluid, drop the pan, let's see what you've got.

Yeah clean from the stick
 
Have you checked that its ATF is at the full mark? The engine MUST be running while you check the transmission's ATF level. It's far better for an automatic transmission to be slightly overfilled than underfilled any at all. If it's low use only ATF+4 to bring it up to the full mark.