(UPDATE) Calling 42RLE Transmission Gurus

[LittleGiant]

I'm hoping to get other opinions on what the transmission shop just told me.

I have an 04 4.0L Auto with the 42rle. It's been slipping (flaring) when shifting from 2-3 and 3-4. Here is what they told me:

The clutch pack has too much clearance from 3rd to 4th. They are calling me again tomorrow with a more detailed report from the tech that worked on it, but said it basically needs an overall. I call bull&%*$ and here's why.

1.The tranny is rebuilt with only 40K on it.
2. I purchased a TCM from Wranglerfix and installed it. I was still having the issues so they are having me send it back and take a look at what they sent me.
3. There has never been a code
4. I unhooked the battery for 24 hours and it stopped slipping all together, but started again after a few times driving it
5. Now all of a sudden, it doesn't slip from 2-3, only 3-4 now.

How does a transmission magically stop slipping from 2-3?

I'm convinced it's electrical. If not, then what?

 

[macleanflood]

I assume the transmission shop drained and replaced the fluid when doing the diagnostic?

If so there's a cause for your change in symptoms.

Are you running a transmission cooler and temperature gauge?

-Mac

 

[LittleGiant]

It stopped slipping from 2-3 before I dropped it off which doesn't make sense to me. What on earth would make it stopped after unhooking the battery but not fix the 3-4 issue?

I am not running a transmission cooler or a temp gauge.

 

[macleanflood]

Thread 'How to install a Derale 20561 transmission cooler on your Wrangler TJ'

Dec 24, 2015

With a recent series of serious overheating incidents while offroading and towing my little pop-up trailer, I decided to hasten my plans to install an auxiliary transmission cooler for my 42RLE automatic transmission. I had added one to my previous TJ that had the more robust 32RH, but Jeep’s newer automatic transmission like my 2004 Rubicon has is far fussier about such things.

High temperatures are the #1 killer of automatic transmissions. So, it makes a lot of sense to make sure it doesn’t overheat while towing trailers, rock crawling, offroading, or just plain crawling in heavy...

• Jerry Bransford
• 32rh 42rle auto tranny derale tranny cooler transmission transmission cooler
• Replies: 298
• Forum: TJ How-to Guides

• 

 

[LittleGiant]

Thread 'How to install a Derale 20561 transmission cooler on your Wrangler TJ'

Dec 24, 2015

With a recent series of serious overheating incidents while offroading and towing my little pop-up trailer, I decided to hasten my plans to install an auxiliary transmission cooler for my 42RLE automatic transmission. I had added one to my previous TJ that had the more robust 32RH, but Jeep’s newer automatic transmission like my 2004 Rubicon has is far fussier about such things.

High temperatures are the #1 killer of automatic transmissions. So, it makes a lot of sense to make sure it doesn’t overheat while towing trailers, rock crawling, offroading, or just plain crawling in heavy...

• Jerry Bransford
• 32rh 42rle auto tranny derale tranny cooler transmission transmission cooler
• Replies: 298
• Forum: TJ How-to Guides

• 

Will installing now fix what I have going on or do I have to fix it then install this to prevent future issues?

 

[macleanflood]

Will installing now fix what I have going on or do I have to fix it then install this to prevent future issues?

That's the million dollar question...chicken or the egg...

You probably need a cooler and a temp gauge. If it fixes the issue fantastic. If not it'll help you get past 40k miles on the next one.

I'd defer to @hear for transmission questions but I'd figure out how to rebuild it yourself. Maybe throwing new frictions and steels might fix it

I'd also check and clean all your grounds and battery terminals.

-Mac

 

[JMT]

It stopped slipping from 2-3 before I dropped it off which doesn't make sense to me. What on earth would make it stopped after unhooking the battery but not fix the 3-4 issue?

I am not running a transmission cooler or a temp gauge.

You need a temp gauge with the sender in the pan, otherwise you don’t have a clue what the temps are.

 

[LittleGiant]

You need a temp gauge with the sender in the pan, otherwise you don’t have a clue what the temps are.

Sorry if I sound like an idiot with this. Any specific one you would recommend?

 

[JMT]

Sorry if I sound like an idiot with this. Any specific one you would recommend?

It’s fine. You don’t sound like an idiot.

This one works well and has everything you need except the bung brazed into the transmission pan.

https://www.amazon.com/dp/B00B81T5Q0?tag=wranglerorg-20

 

[LittleGiant]

Im seeing adapters for the sensor and also reading that the 42rle already has installed. Can’t seem to find a specific brand of sensor though. Odd

 

[L J]

Sorry if I sound like an idiot with this. Any specific one you would recommend?

https://blackmagicbrakes.com/ols/products/42rle-transmission-pan

 

[hear]

You asked "if not electrical, then what?" Intermittent problems are the worst. Your said no codes? The computer controls your shifts so it's way harder to diagnose if there are no codes. But my usual strategy is to look at what's in common with what works and what doesn't in terms of clutch/band applications:

• 2nd
  • uses the Underdrive clutch
  • uses the 2/4 holding clutch
• 3rd (drive)
  • uses the underdrive clutch
  • uses the overdrive clutch
• 4th (overdrive)
  • uses underdrive clutch
  • uses low/reverse holding clutch

So immediately we can see that the underdive clutch is probably not the issue since all 3 gears use that clutch pack. From this it's impossible to draw a conclusion about what's wrong since 2 problems don't have anything in common that aren't also part of another working gear. So it must be something else if they are connected. If they aren't, then yay that the 2-3 shift works, and then lets figure out why the 3-4 is problematic.

Is it clutch clearance? Maybe, but why did it start being a problem only after you reset the computer? Also, unless the 42RLE has some real magic going on bewteen the drums and the TCM, there's no way they can tell that the clearance is wrong on that clutch pack without first having torn it down at least part way. MAYBE you can measure that with the valve body off.... it it were a 32RH (which is isn't, obviously) you have to take it 75% of the way apart to measure it.

A pressure test as described in the FSM is probably what is needed next. Maybe the shop did that and can tell you what they found? Really I just want to know how they determined that the clearance was out of spec. Maybe with enough experience you just know?


But yeah, this is electrical, and most likely not solenoid related.

 

[LittleGiant]

You asked "if not electrical, then what?" Intermittent problems are the worst. Your said no codes? The computer controls your shifts so it's way harder to diagnose if there are no codes. But my usual strategy is to look at what's in common with what works and what doesn't in terms of clutch/band applications:

• 2nd
  • uses the Underdrive clutch
  • uses the 2/4 holding clutch
• 3rd (drive)
  • uses the underdrive clutch
  • uses the overdrive clutch
• 4th (overdrive)
  • uses underdrive clutch
  • uses low/reverse holding clutch

So immediately we can see that the underdive clutch is probably not the issue since all 3 gears use that clutch pack. From this it's impossible to draw a conclusion about what's wrong since 2 problems don't have anything in common that aren't also part of another working gear. So it must be something else if they are connected. If they aren't, then yay that the 2-3 shift works, and then lets figure out why the 3-4 is problematic.

Is it clutch clearance? Maybe, but why did it start being a problem only after you reset the computer? Also, unless the 42RLE has some real magic going on bewteen the drums and the TCM, there's no way they can tell that the clearance is wrong on that clutch pack without first having torn it down at least part way. MAYBE you can measure that with the valve body off.... it it were a 32RH (which is isn't, obviously) you have to take it 75% of the way apart to measure it.

A pressure test as described in the FSM is probably what is needed next. Maybe the shop did that and can tell you what they found? Really I just want to know how they determined that the clearance was out of spec. Maybe with enough experience you just know?


But yeah, this is electrical, and most likely not solenoid related.

That’s definitely good info. I’m told I’ll be getting a call tomorrow with more detailed info. I’ll do my best to take notes and bring them to class tomorrow and share. Haha stay tuned.

 

[MikeE024]

Thread 'How to install a Derale 20561 transmission cooler on your Wrangler TJ'

Dec 24, 2015

With a recent series of serious overheating incidents while offroading and towing my little pop-up trailer, I decided to hasten my plans to install an auxiliary transmission cooler for my 42RLE automatic transmission. I had added one to my previous TJ that had the more robust 32RH, but Jeep’s newer automatic transmission like my 2004 Rubicon has is far fussier about such things.

High temperatures are the #1 killer of automatic transmissions. So, it makes a lot of sense to make sure it doesn’t overheat while towing trailers, rock crawling, offroading, or just plain crawling in heavy...

• Jerry Bransford
• 32rh 42rle auto tranny derale tranny cooler transmission transmission cooler
• Replies: 298
• Forum: TJ How-to Guides

• 

That guy had no idea if the Derale cooler worked well for his 42RLE because he never made the effort to install a temp gauge. He’d install a dildo and tell everyone how great it is as long as he got it for free.

 

[LittleGiant]

You asked "if not electrical, then what?" Intermittent problems are the worst. Your said no codes? The computer controls your shifts so it's way harder to diagnose if there are no codes. But my usual strategy is to look at what's in common with what works and what doesn't in terms of clutch/band applications:

• 2nd
  • uses the Underdrive clutch
  • uses the 2/4 holding clutch
• 3rd (drive)
  • uses the underdrive clutch
  • uses the overdrive clutch
• 4th (overdrive)
  • uses underdrive clutch
  • uses low/reverse holding clutch

So immediately we can see that the underdive clutch is probably not the issue since all 3 gears use that clutch pack. From this it's impossible to draw a conclusion about what's wrong since 2 problems don't have anything in common that aren't also part of another working gear. So it must be something else if they are connected. If they aren't, then yay that the 2-3 shift works, and then lets figure out why the 3-4 is problematic.

Is it clutch clearance? Maybe, but why did it start being a problem only after you reset the computer? Also, unless the 42RLE has some real magic going on bewteen the drums and the TCM, there's no way they can tell that the clearance is wrong on that clutch pack without first having torn it down at least part way. MAYBE you can measure that with the valve body off.... it it were a 32RH (which is isn't, obviously) you have to take it 75% of the way apart to measure it.

A pressure test as described in the FSM is probably what is needed next. Maybe the shop did that and can tell you what they found? Really I just want to know how they determined that the clearance was out of spec. Maybe with enough experience you just know?


But yeah, this is electrical, and most likely not solenoid related.

Silly question…what part of what you described is electrical? It all sounds mechanical to me

 

[hear]

That guy had no idea if the Derale cooler worked well for his 42RLE because he never made the effort to install a temp gauge. He’d install a dildo and tell everyone how great it is as long as he got it for free.

Unless it came from autozone.

 

[hear]

Silly question…what part of what you described is electrical? It all sounds mechanical to me

What I described was what it could be if it were mechanical. But I low key proved it was electrical by reductio de absurdum. I knew that Latin I learned would come in handy one day.

 

[LittleGiant]

What I described was what it could be if it were mechanical. But I low key proved it was electrical by reductio de absurdum. I knew that Latin I learned would come in handy one day.

lol any specific thoughts on what it would be if electrical? TCM?

 

[rasband]

lol any specific thoughts on what it would be if electrical? TCM?

Yeah, since you have a separate TCM I would trace it out.

 

[hear]

lol any specific thoughts on what it would be if electrical? TCM?

Given that resetting it gave you a new behavior, the computer seems to be the most likely culprit. Coincidences definitely happen, so there's always a chance that you had a sticky valve that clear around the same time that a solenoid died, but Occam's Razor points directly at the PCM.