Is it true that chrysler transmissions have cooling problems?

[kage860]

http://etereman.com/blog/fiat-transmission/what-problems-plague-the-chrysler-42lre-transmission


Found that on google after reading about the problem here:

http://www.thetruthaboutcars.com/2017/10/piston-slap-ultradriving-budget-beater/

I probably dont care enough to go out and install a bigger cooler any time soon.

 

[JasonJ]

I'd say it's generally true.... but a lot of factors come into play- how often was fluid and filter changed, was the vehicle ever used to tow, did it tow more than it should have, etc....

I did read that Wrangler owners with the 42RLE like to overfill the trans by about a qt so that when they are on inclines the fluid pump is still able to draw fluid into the transmission... although I do not know if they have a deeper pan than ours or not... so it may not be applicable to a KJ.

It's always a good idea to add an aux trans cooler, or upgrade the existing one, regardless if the trans has a known issue with getting hot. Those articles sound very worst-case scenario/doom and gloom compared to my experience.

 

[TwoBobsKJ]

http://etereman.com/blog/fiat-transmission/what-problems-plague-the-chrysler-42lre-transmission


Found that on google after reading about the problem here:

Piston Slap: Ultradriving the Budget Beater?

I probably dont care enough to go out and install a bigger cooler any time soon.

Funny how the article says the internet is "littered with stories about the 42RLE" but then goes on to talk about the equally awful Ford AXOD ****** - so the 42RLE didn't corner the market on issues. The thing about the web is you don't take time out of your busy day to comment about how WELL your transmission is shifting and getting you to the local Piggly Wiggly, work, kids ball game and Grandma's house with no issues. We assume they'll work and they usually do. Human nature says we'll talk about things that go wrong before we'll comment on things that are going well.

In 212,000 miles I had two trannies in my '03 KJ - the first one wasn't maintained and took me to 103,000 when the clutches dumped. The PO didn't do fluid changes and that's one thing Chrysler products require is on-time fluid flushes. Second, the KJ has a trans cooler from the factory so the cooling problems those articles mention with the 42RLE are pretty much taken care of from the get go.

I'll use forums like these to help me diagnose and fix issues but I view postings of problems with a grain of salt. The first place folks go these days to discuss problems is the model's forum so of course when you jump on Google and do a search for "42RLE problems" the search engine does it's job and finds problems with 42RLE trannies. Pretty much a self-fulfilling search I'd say. Same for those Ford AXOD transmissions mentioned in the article.

Drive your KJ and enjoy it, do fluid changes on-time and with the proper fluids and your Jeep will treat you well. Will it break somewhere down the road? Probably, but mechanical things break from time to time.

My 2 cents.

Bob

 

[tommudd]

Like Bob stated, if you are looking for an issue the internet will certainly hook you right up with others who want to complain
No one ever gets on forums and posts every where mine has X number of miles and nothing has broken / worn out yet.

 

[tommudd]

I'd say it's generally true.... but a lot of factors come into play- how often was fluid and filter changed, was the vehicle ever used to tow, did it tow more than it should have, etc....

I did read that Wrangler owners with the 42RLE like to overfill the trans by about a qt so that when they are on inclines the fluid pump is still able to draw fluid into the transmission... although I do not know if they have a deeper pan than ours or not... so it may not be applicable to a KJ.

It's always a good idea to add an aux trans cooler, or upgrade the existing one, regardless if the trans has a known issue with getting hot. Those articles sound very worst-case scenario/doom and gloom compared to my experience.

In some cases the aux. trans cooler could in fact keep the fluid too cool causing some issues . Automatics are designed to work at a certain temperature. Heat is a huge cause of transmission failures but running too cool is bad also. Just as an engine has to run hot enough the trans has to run hot enough to get rid of any condensation that builds up inside and to keep the viscosity at the correct level for best operation. Depending on how a trans cooler is installed it could help or in some cases hurt the trans.

 

[Aceofspades]

^ true. I can't get get lock-up on my convertor until the trans temp goes to 185 on my other vehicle and well with a huge cooler I added. My 5 mile winter morning rides to work it almost never reaches it

 

[JasonJ]

Good info .. good info.

I wonder if my Innova 3160d displays transmission temperature from the OBD system.... wish we had a gauge for that.

 

[tommudd]

^ true. I can't get get lock-up on my convertor until the trans temp goes to 185 on my other vehicle and well with a huge cooler I added. My 5 mile winter morning rides to work it almost never reaches it

I used to add oil coolers to all my Harleys but of course had to cover them when temps went down or was not a good sound LOL When riding at 25-30 degrees almost had to install a heater in front of the cooler :happy175:

 

[HoosierJeeper]

My trans overheated once, but I think a slipping torque converter caused it to overheat which then made it slip even more. Never got the idiot light on though. Had to get a rebuild.

 

[tjkj2002]

^ true. I can't get get lock-up on my convertor until the trans temp goes to 185 on my other vehicle and well with a huge cooler I added. My 5 mile winter morning rides to work it almost never reaches it

You got a trans issue if your not going into 4th till 185 degrees ATF temp,should be 80 degrees.



As far as the 42RLE and heat issues.............................

The stand alone trans cooler is the whole issue,adding a bigger stand alone cooler is not the answer either.You need to swap in a radiator from a 2002 KJ with the 45RFE and mod the trans cooler lines to run through the in-radiator trans cooler(built into the '02 radiator) and then to the OE stand alone cooler,then back to the trans.

 

[Leeann]

^ true. I can't get get lock-up on my convertor until the trans temp goes to 185 on my other vehicle and well with a huge cooler I added. My 5 mile winter morning rides to work it almost never reaches it

I have a 2 mile drive to work. My Liberty is up to full temp before I reach halfway and will go into lockup long before that.

 

[HoosierJeeper]

x2. Mine locks up the first time I'm at an appropriate speed. Holds gears a tad longer when it's cold, but that's programmed in to help heat up the trans.

 

[TwoBobsKJ]

You got a trans issue if your not going into 4th till 185 degrees ATF temp,should be 80 degrees.



As far as the 42RLE and heat issues.............................

The stand alone trans cooler is the whole issue,adding a bigger stand alone cooler is not the answer either.You need to swap in a radiator from a 2002 KJ with the 45RFE and mod the trans cooler lines to run through the in-radiator trans cooler(built into the '02 radiator) and then to the OE stand alone cooler,then back to the trans.

That's what I did - and I'd link to the thread but all the pics are gone thanks to Photobucket :favorites68:

Bob

 

[Aceofspades]

Yeah. It's my "other vehicle" not the liberty but now it's a summer only car and I use the 02/03 libterys yeae round
https://youtu.be/O-qjcoyIm_M

 

[renegade 04]

On my libby I have a dual core all aluminum radiator with the in radiator transmission cooler as well as the Mopar extreme temperature external cooler and the jeep loves it. I have never seen temps above 160 since I installed the set up.

 

[djtimyd]

isn't the engine temperature supposed to be warmer? I'm not talking 220°+, but isn't the factory thermostat a 195°? IIRC, the jeep will run rich - ie dump more gas than it needs to when its colder, in a vain attempt to get it up to normal operating temperature.

I could be wrong here... its happened a time or fifty.

 

[HoosierJeeper]

I think we're talking trans temps

 

[djtimyd]

OK, I thought so... but the post by renegade 04 confused me with talk of the replacement dual core all aluminum radiator. Apparently I got easily distracted by another shiny object.

How does one monitor the transmission temperature? Does the Mopar Extreme Temperature External Cooler come with a gauge?

 

[HoosierJeeper]

You can't monitor it unless you add a sensor. I think PML makes a pan that has a bung for it.

 

[tjkj2002]

On my libby I have a dual core all aluminum radiator with the in radiator transmission cooler as well as the Mopar extreme temperature external cooler and the jeep loves it. I have never seen temps above 160 since I installed the set up.

Mine normally runs about 160-170 with the stock radiator cooler and 28,000lbs GVWR trans cooler.Will creep to 170-180 on the trail but that is expected.