42RLE Solenoid Pack & Valve Body Rebuild

AjRagno

TJ Enthusiast
Supporting Member
Joined
Dec 27, 2019
Messages
638
Location
US
The 2-4 and 3-4 up shifts are no longer as fast or smooth as they used to be during hard acceleration so I suspect the solenoid pack and valve body internals are bleeding off pressure.

How difficult is it to remove and work on the valve body? It looks like just getting it out of the case is a major task.

I’m way up there in miles (244,000) but the transmission has been well-maintained, no issues unless I put the pedal to the floor.

I can replace the solenoid block and refresh the valve body with a Transgo kit for around $200. To replace or rebuilt the transmission is around $3000.

I’m considering just replacing the transmission, but if working on the valve body is not as bad as it looks, I may try that first.

Thanks.
 
Personally I'd take the Jeep to a really good transmission shop or dealer that has a tool that can read the transmission data. It tracks wear of the shift clutches based on the shift time. Generally slow shifts mean worn clutches and a rebuild but the shop can tell you for sure.
 
The 2-4 and 3-4 up shifts are no longer as fast or smooth as they used to be during hard acceleration so I suspect the solenoid pack and valve body internals are bleeding off pressure.

How difficult is it to remove and work on the valve body? It looks like just getting it out of the case is a major task.

I’m way up there in miles (244,000) but the transmission has been well-maintained, no issues unless I put the pedal to the floor.

I can replace the solenoid block and refresh the valve body with a Transgo kit for around $200. To replace or rebuilt the transmission is around $3000.

I’m considering just replacing the transmission, but if working on the valve body is not as bad as it looks, I may try that first.

Thanks.
it's not that bad of a job, I did that to mine yet I had never worked on an automatic transmission before.

First, I used the Stage 1 version of the Transgo kit, not any of the stiffer shifting versions. It shifts nicely with that kit and it works well. It includes many of the piston seals and there's a slight modification or two like slightly enlarging a hole in the valve body plate with the provided drill bit. Its instructions are very good and self-explanatory.

Note the tub of ATF-dissolvable "Assembly Goo" on the left. You'll need that to hold the pistons up inside the cylinders since they're inserted up into it and they would fall out before you could install the valve body if you didn't use the assembly grease. Make sure to get the kind that ATF will dissolve.

20180626_093840_resized.jpg


Where the "worm trails" valve cylinders, etc. are concerned, cleanliness is next to godliness here. I went through 3-4 cans of brake cleaner flushing everything thoroughly before reassembing it.

20180626_122545_resized.jpg


That's the hole you'll enlarge with the drill bit included in the Transgo kit.

20180626_124903_resized.jpg


The bluish-greenish thing on the right is the new solenoid pack. I'd make sure to only use Mopar.

20180626_142936_resized.jpg


The Mopar Factory Service Guide will be a big help, and you can Google for how various Jeepers replaced their solenoid pack. There's lots of help available out there.

You'll need to buy 1/4" and 3/8" clicker-style torque wrenches. The ft-lbs. settings are low enough that anything bigger won't be accurate. I bought mine at Harbor Freight Tools and they're $20 or less, often $10 when they're on sale. Don't let that low price fool you, they're actually very good quality with good repeatability.

Oh, there are 6-8 little nylon/plastic check valve balls that are in those worm trails. Make sure you note where yours were when you split the valve body. I bought a set of new check valve balls for a few bucks but figured out the factory ones were still fine. Probably a good idea to get them anyway, especially if you lose one.
 
  • Like
Reactions: AjRagno and Fixer6
Thanks, I appreciate the feedback.

I'm pretty sure the clutch packs are still good. The transmission is not slipping or flaring. I also drained the pan tonight and the fluid was still red and clear - last changed at 221,266.

I spoke with a couple of rebuilders last week. One advised that'd I'd gotten enough miles out of the transmission and shouldn't worry about it at this point, just drive it till it dies. The other suggested the solenoids may be leaking and allowing a loss of pressure.

I'll plan on sourcing the parts and tools over the next few days.
 
  • Like
Reactions: Jerry Bransford
Following up on this. I never did get around to removing the valve body but the transmission is now doing fine at 250,000 miles and this hasn't been an issue since replacing the PCM a couple of months back.

I couldn't find instructions for the TransGo kit anywhere online so I've attached them for others for future reference.

Transmission pan and magnet at 244,000 miles/60,000 miles since previous filter change:
View attachment 191676

TransGo kit, boost valve and solenoid pack:
View attachment 191679

TransGo 42RLE Instructions:
View attachment 191680
View attachment 191681View attachment 191682View attachment 191683View attachment 191684
 
Last edited:
  • Like
Reactions: Jerry Bransford
Reviving this thread, looking for some advice. 2003 Rubicon 4.0L with 42RLE, 180k miles. Bought it 6 months ago with torque converter shudder. Flushed fluid and changed filter, shudder is still present but better.
A couple of weeks ago I had just got up to speed on the freeway and CEL came on and RPM spiked. Transmission was stuck in limp mode. P1776 was the only code. Cleared code and then drove fine.
Now I get the CEL and limp mode about once a week. I have to clear the code, then it will drive fine for a while and then come back.

My questions:
1. Do I take it to a dealer that can read DBRIII so I can go through the TSB to determine if it is mechanical or electrical?
2. Do I bite the bullet and install the Transgo kit for the P1776 code AND replace the solenoid packs?

TIA for the help.
 
I wouldn't expect the Transgo kit to really fix anything but it can't hurt to install while you're in there replacing the solenoid pack. No guarantees your limp mode and P1776 code is caused by a bad solenoid pack but the odds are good it is. I got lucky with mine that went into limp mode with a P0755 code that a new solenoid pack fixed. I also installed a Transgo Stage 1 (mildest) kit and it still shifts pretty much the same. It does a few easy modifications that Transgo says either fixes or improves a few things inside the 42RLE.

Just make sure to buy a half-dozen cans of brake cleaner to make sure the inside of the valve body is CLEAN when you're all done. Also required will be a small tub of ATF-compatible "Assembly Goo" for making it possible for the pistons to stay up in position while you reinstall the valve body from the bottom. Just for peace of mind I also installed all new check balls (cheap little nylon balls) as well as a new Mopar Range Selector Switch since it can cause problems too. Make sure you note exactly what little "worm channels" in the valve body the check balls came out of so you put them exactly back where they came from.

Overall it was not a technically challenging job but it was however a little scary since I can't even spell automatic transmission. I did this job two years ago and the transmission has been flawless ever since so go for it and just take your time. The FSM has lots of info you'll want to refer to.

Oh, make sure to buy a 1/4" torque wrench! Some of the little bolts need to be torqued evenly to precise tightnesses and 3/8" or 1/2" torque wrenches are nowhere near accurate enough at those low settings. I paid $19.95 for mine at Harbor Freight Tools and it worked great. Actually I think it was on sale for $9.95, it's worth more than it costs lol. The solenoid pack is what's under the light greenish-blue ring, the range selector is under that tall steel shift control rod.

The drill laying on the valve body plate is what's used to make one of the mods in the Transgo kit plus some replacement valve parts.

Here are a couple photos from my job...

20180626_122545_resized.jpg


20180626_124903_resized.jpg


20180626_093840_resized.jpg
 
Thank you Jerry for the thorough reply and photos. A couple more things:

1. I was planning on doing the Transgo kit shown below only. Does this make sense?

2. Do you know the part number of the Mopar Solenoid Pack?

1620834220126.png
 
I went ahead and bought 3 different kits from Transgo and the Mopar solenoid pack. I'll follow-up after install in a few weeks. More likely I'll reach out when I get stuck. Thanks again.


1620840316498.png
 
I went ahead and bought 3 different kits from Transgo and the Mopar solenoid pack. I'll follow-up after install in a few weeks. More likely I'll reach out when I get stuck. Thanks again.


View attachment 251903
There’s a series of videos on YouTube. I think the most difficult parts will be removing the valve body and then also keeping the accumulators in place while reinstalling.

 
You keep the accumulators in place while installing the valve body with the ATF compatible Assembly Goo I mentioned above. ATF dissolves it once you have the valve body installed.
 
While I'm waiting for valve body parts I decided to do a dry run. There were a few things I learned that I didn't find anywhere else:

1. It was helpful to remove the shift cable mounting bracket from the transmission to access the left side connector (2 bolts with 13mm heads).
2. I was concerned about reassembling the shift cable to the shift shaft correctly but it only goes on 1 way as there is a flat on the shaft and on the bracket.
3. I found removing the shift console to be very helpful for accessing the right side connector and the shifter shaft. My shifter shaft was rusty and I wanted to clean it up before trying to pull it through the transmission case. Here are some photos of what it looks like with the console and access panel removed (FYI I do have a 1.25" body lift and a 1" MML):

1621016702320.png

1621016754040.png

1621016820403.png
 
Just wait until you start trying to get the electrical connector on top of the transmission for the Solenoid Pack disconnected. Then the shifter cable bracket that clamps to the vertical shift rod that protrudes from the top of the transmission. Both of those are in areas that are hard to work in, it was the least fun part of all of this so far as I am concerned.
 
I appreciate all of you on these forums. I have been able to remedy quite a few problems through the years.
Can anyone recommend a descent trans shop for a troubleshoot/rebuild on my 42rle? Someone with experience with this particular trans would help to make me feel better having someone wrench on my ride. I normally do all my own work but a auto trans replacement feels dangerous with my limited tools and space.
I’m in So Cal. Thank you.
—2004 tj rubicon on 35s 5:13 gears 160k miles. Bought the jeep at 110k miles with the tranny shifting a bit off thinking I will need to rebuild tranny. (Got a good deal on it) but she just keeps going. Do not want to get stranded so I think it is time to get it looked at by a professional.
Added cooler right away. Trans Temp gauge never gets to hot
Fluid looks good
Changed fluids and filter
Fluid level is tits
Swapped pcm with my brothers (same year and model) same problem
Proper fluid in trans
Overdrive sucks on these things!
 
I appreciate all of you on these forums. I have been able to remedy quite a few problems through the years.
Can anyone recommend a descent trans shop for a troubleshoot/rebuild on my 42rle? Someone with experience with this particular trans would help to make me feel better having someone wrench on my ride. I normally do all my own work but a auto trans replacement feels dangerous with my limited tools and space.
I’m in So Cal. Thank you.
—2004 tj rubicon on 35s 5:13 gears 160k miles. Bought the jeep at 110k miles with the tranny shifting a bit off thinking I will need to rebuild tranny. (Got a good deal on it) but she just keeps going. Do not want to get stranded so I think it is time to get it looked at by a professional.
Added cooler right away. Trans Temp gauge never gets to hot
Fluid looks good
Changed fluids and filter
Fluid level is tits
Swapped pcm with my brothers (same year and model) same problem
Proper fluid in trans
Overdrive sucks on these things!
What do you mean by a bit off? The TCC lockup behaviors can make it seem quirky if you’re not aware of the programming, but you should get a code if anything it not working properly.

Swapping the PCM on your ‘04 won’t affect the transmission. There’s a transmission control module (TCM) mounted on the driver side of the engine bay.

My advice with the 42RLE is to leave overdrive on until the 2-3 shift occurs. Otherwise the TCC will lock as soon as 3rd gear engages.
 
What do you mean by a bit off? The TCC lockup behaviors can make it seem quirky if you’re not aware of the programming, but you should get a code if anything it not working properly.

Swapping the PCM on your ‘04 won’t affect the transmission. There’s a transmission control module (TCM) mounted on the driver side of the engine bay.

My advice with the 42RLE is to leave overdrive on until the 2-3 shift occurs. Otherwise the TCC will lock as soon as 3rd gear engages.
 
What do you mean by a bit off? The TCC lockup behaviors can make it seem quirky if you’re not aware of the programming, but you should get a code if anything it not working properly.

Swapping the PCM on your ‘04 won’t affect the transmission. There’s a transmission control module (TCM) mounted on the driver side of the engine bay.

My advice with the 42RLE is to leave overdrive on until the 2-3 shift occurs. Otherwise the TCC will lock as soon as 3rd gear engages.
Ooopss. Yes. The TCM was swapped not the PCM.
forgot to mention the shifting has slowly progressed worse and worse.
sort of a slip to a hard shift 2-3. Or while crawling, a slip to hard shift 1-2.