Transmission Problem (42RLE)

[MikeE024]

Coming home from the VA today, my jeep decided that it didn't want to move from a complete stop when I pressed the gas pedal. I have a 42RLE auto.

The transmission has a newish Mopar filter and ATF+4 (the coolant was also bleed from the cooler lines a few months back).

The fluid level is just barely under the full on the dipstick at operating temperature (checked today at 215F). My Harbor Freight infrared thermometer gave me a temperature of 175-180F at the transmission pan, and the passive cooler in front of the condenser was around 160F. I didn't notice any burning smell from the new fluid and it was cherry red/transparent looking on the dipstick.

While looking under the jeep in traffic, I heard an audible click. I got back in the jeep and was able to drive it up the road. Traffic was very bad, which "allowed" me to test it over and over until I could get to a side road. The jeep seemed to struggle to move uphill coming out of a dip (coming from a complete stop due to traffic).

I need to be mindful that the audible click that I heard could have been from my A/C compressor clutch since my A/C was running when I hastily jumped under my jeep in traffic.

What I heard was likely the AC clutch or a solenoid latching, but I don't know if it was to my transmission. My guess is no since I was in park at the time that I heard the noise, but I could be wrong as I'm not a guru on the inner workings of an auto transmission.

Does anyone have thoughts on how I should investigate this? I'd hate to drop the pan only to stare at the parts without a game plan or knowledge. Are there known solenoids that cause this issue that I can access from the pan, or does this sound like something that a shop will need to dive into?

Note: I was able to get the vehicle home, but it seemed to rev high from complete stops (just to get it to move). It drove fine once I got above 5-10 mph.

Any help is greatly appreciated.

 

[MikeE024]

Additional thought:

I don't know if this matters, but ever since I got the jeep, 4Hi has basically been useless offroading because it seemed like I needed to rev a bit to much to go anywhere while climbing rocks. For this reason, I've greatly preferred wheeling in 4Lo and never felt tempted to change the locker switches to allow me to run lockers in 4Hi.

This is my first experience offroading a jeep, so I have no reference to determine if Jeep should have performed better offroading in 4Hi.

 

[Jerry Bransford]

If you're not checking your ATF level it may not be as full as you think it is. While checking the ATF level the engine MUST BE RUNNING. If it's not running the dipstick will shown an erroneous level that is higher than it really is.

I'd bring the ATF level up to the top of the full mark, if not slightly over, while the engine is running. Make sure to ONLY add ATF+4, no other type of ATF is correct. Even being a little low can cause shifting issues. I keep mine overfilled by a half-quart or so so the ATF pickup won't pickup air during a steep climb. Where an automatic transmission is concerned, it's far better to be slightly overfilled than to be underfilled.

And when doing offroad trails, it's best to be in 4Lo not 4Hi which is only meant for onroad use when the roads are covered in ice or snow.

 

[MikeE024]

If you're not checking your ATF level it may not be as full as you think it is. While checking the ATF level the engine MUST BE RUNNING. If it's not running the dipstick will shown an erroneous level that is higher than it really is.

I'd bring the ATF level up to the top of the full mark, if not slightly over, while the engine is running. Make sure to ONLY add ATF+4, no other type of ATF is correct. Even being a little low can cause shifting issues. I keep mine overfilled by a half-quart or so so the ATF pickup won't pickup air during a steep climb. Where an automatic transmission is concerned, it's far better to be slightly overfilled than to be underfilled.

And when doing offroad trails, it's best to be in 4Lo not 4Hi which is only meant for onroad use when the roads are covered in ice or snow.

Hi Jerry, thanks for the message. It was running and at temp after a 25-minute drive. I'll add more Mopar ATF+4 until I'm over the high mark on the dipstick. I understand that I can check the level in the park/neutral for the 42RLE (while 32RH folks must do so in neutral).

It originally got stuck in traffic in a perfectly level position. I slugged it home, but I'm pretty concerned.

 

[Jerry Bransford]

It originally got stuck in traffic in a perfectly level position. I slugged it home, but I'm pretty concerned.

Yeah that doesn't sound good at all.

 

[MikeE024]

Yeah that doesn't sound good at all.

If the transmission needs work should I let a reputable guy rebuild it, or does it make sense to get a remanufactured transmission (like people prefer to do with our 4.0L engine)?

Also, are there any parts that would be wise to upgrade/beef up if I have to go this route?

 

[Irun]

If the transmission needs work should I let a reputable guy rebuild it, or does it make sense to get a remanufactured transmission (like people prefer to do with our 4.0L engine)?

Also, are there any parts that would be wise to upgrade/beef up if I have to go this route?

There isn't much you can do for these to strengthen them, so it's better to stay local, in the event there's a problem. If you get it rebuilt, ask them for a detailed list of what they replace. For example, if they don't replace the solenoids, with Mopar replacements, I'd make sure that was part of the package.

 

[Jerry Bransford]

I'd rather mine was rebuilt than install a replacement unless it was done by a shop known for their quality of work and history with the 42RLE transmission. Too bad you're not closer to SoCal, there's one transmission shop in Westminster that is constantly recommended for Jeep transmissions, they really know them.

I'd start asking around in your local Jeep community to see if there's a transmission shop they have experience with that they can recommend. Here's a recent thread on this subject with a few links to recommended providers though they're not in Arizona. https://wranglertjforum.com/threads...e-replacement-transmission.47647/#post-945597

 

[pagrey]

The 42RLE almost always throws a code when it fails and or goes in limp home mode. I'd be surprised if something else wasn't going on. No codes I wouldn't even suspect trans on my Jeep. I don't know what's going on with yours but it seems really odd it doesn't throw a code. It knows the exact slip of the input shaft vs output shaft at all times.

 

[MikeE024]

I'd rather mine was rebuilt than install a replacement unless it was done by a shop known for their quality of work and history with the 42RLE transmission. Too bad you're not closer to SoCal, there's one transmission shop in Westminster that is constantly recommended for Jeep transmissions, they really know them. I'd start asking around in your local Jeep community to see if there's a transmission shop they have experience with that they can recommend. Here's a recent thread on this subject with a few links to recommended providers. https://wranglertjforum.com/threads...e-replacement-transmission.47647/#post-945597

From what I've gathered, the guy that I've sought out to do my future re-gear is known as THE GUY for drivetrains and transmissions on jeeps here in Tucson (Lloyd's transmission). He's a super nice older gentleman that loves working on our rigs. I have a feeling that this will be my route, but I'll check the link you sent just in case. Thanks for sending that over!

 

[MikeE024]

The 42RLE almost always throws a code when it fails and or goes in limp home mode. I'd be surprised if something else wasn't going on. No codes I wouldn't even suspect trans on my Jeep. I don't know what's going on with yours but it seems really odd it doesn't throw a code. It knows the exact slip of the input shaft vs output shaft at all times.

I don't have any P0 codes, but I should ask for clarification on what limp mode is & how to diagnose if I'm in limp mode.

I read that it doesn't let you go over 3k RPMs, but I wouldn't really know about that because of my horrible tire size/ gearing combination. Or, maybe it's been in limp mode since I bought it and I never knew any better.

 

[pagrey]

Limp is stuck in 2nd I think, you'd know. I think it also throws a code, does the check engine light work when you have the key on but not running?

 

[MikeE024]

Limp is stuck in 2nd I think, you'd know. I think it also throws a code, does the check engine light work when you have the key on but not running?

If that's the case, then I have not been driving around in limp mode for months. I was on the highway right before the jeep decided to not move from a complete stop. However, maybe I'm in limp mode now.

I may chance driving it to see if I can get it to shift into third. Thanks for the heads up.

 

[pagrey]

Check that check engine light, find a code scanner and read the codes. Really odd it's not talking to you with it driving so poorly.

 

[MikeE024]

The 42RLE almost always throws a code when it fails and or goes in limp home mode. I'd be surprised if something else wasn't going on. No codes I wouldn't even suspect trans on my Jeep. I don't know what's going on with yours but it seems really odd it doesn't throw a code. It knows the exact slip of the input shaft vs output shaft at all times.

I don't have any P0 codes, but I should ask for clarification on what limp mode is & how to diagnose if I'm in limp mode.

Limp is stuck in 2nd I think, you'd know. I think it also throws a code, does the check engine light work when you have the key on but not running?

I want to be fully transparent and share that I recently communicated bad information. This is very important for me to get right, and I apologize for my error.

1) I do not have an engine light popping with the vehicle running (it works), but I incorrectly assumed the engine light always pops when you have P0 codes (when the engine indicator bulb is working as it does now). I said that I don't have P0 codes because I didn't see the engine light on. That was non-factual and I apologize for my mistake. It is factual that my engine light is not on with the engine running.

2) I plugged up my Torque Pro app / OBD 2 dongle and found that I do have two codes:
- P0700 (Transmission Control System); and
- P0740 (Torque Converter Clutch Circuit).

 

[MikeE024]

If my jeep gets me to the store ok, I will buy more ATF+4 to put the fluid level a tad over the fill line. I cleared the codes as well and will do so again after I add more fluid.

I haven't had this issue before, so I'm not sure what to think about it being (1) the fluid or maybe (2) the torque converter going bad when my symptom was that the transmission quietly stopped working, but then worked again (at least in partial capacity) to get me home.

 

[Terry Tiemeyer]

Doesn’t the computer sometimes make these act strange. Mine will sometimes not downshift until I shift into neutral and back into gear and then it seems fine. It’s like it doesn’t want to downshift.ive never had a code.

 

[MikeE024]

Doesn’t the computer sometimes make these act strange. Mine will sometimes not downshift until I shift into neutral and back into gear and then it seems fine. It’s like it doesn’t want to downshift.ive never had a code.

If that's the case, are there certain wires that one would recommend that I check for power or resistance?

I got the jeep pretty wet a week ago (but no issues until today and I've driven it multiple times every day).

 

[Jerry Bransford]

Your symptoms don't quite remind me of a PCM problem but it's possible since 05/06 TJs have PCM issues with the 42RLE. Mark @Wranglerfix at www.wranglerfix.com is the guru of this subject, let's see what he has to say.

 

[pagrey]

Codes make sense, trans has issues, PCM isn't the issue.