Transmission overheating

[Marshall 55]

My 2005 automatic Rubicon trans is running hot. I can drive it 40-60 miles before the CEL comes on. Let it sit for 10min clear code and I'm good for another 50 miles. This doesn't happen driving around town. Dropped pan no metal on magnets,color good but does smell burnt. Changed filter and added trans cooler and had a diagnostics scan done(results attached). I'm pretty sure I'm going to have to replace the trans. I have a homemade camping trailer that weighs around 1600lbs loaded that I pull with no problems in the mountains or on the beach. Did that cause my trans to have problems over time(been pulling for 3yrs on several trips)? Should I switch to the 32rh? If so,would I have to re-gear? I plan on keeping this TJ for life and a transmission is a huge investment for me so I really want to make the right decision here. Any and all suggestions are appreciated. I'm located in Darlington, SC so any shops bear me that yall suggest are also welcome!

 

[Jerry Bransford]

It's overheating even with an external/auxiliary transmission cooler? How is the ATF level? Are you checking the ATF level while the engine is running? If the engine isn't running the ATF dipstick will erroneously say there's more ATF present than there really is.

 

[Marshall 55]

It's overheating even with an external/auxiliary transmission cooler? How is the ATF level? Are you checking the ATF level while the engine is running? If the engine isn't running the ATF dipstick will erroneously say there's more ATF present than there really is.

Level is good and yes checking it running. And yes getting hot with auxiliary cooler.

 

[mrblaine]

Level is good and yes checking it running. And yes getting hot with auxiliary cooler.

What is your tire size and axle gearing?

 

[Jerry Bransford]

Level is good and yes checking it running. And yes getting hot with auxiliary cooler.

Did you splice the aux cooler into the driver's-side transmission cooler output line? That gives better cooling for the ATF than if the cooler is spliced into the passenger side where the 42RLE is concerned.

 

[mrblaine]

Did you splice the aux cooler into the driver's-side transmission cooler output line? That gives better cooling for the ATF than if the cooler is spliced into the passenger side where the 42RLE is concerned.

As important is we need to know the answers to my other question and then what cooler was installed. He is working it hard with the trailer, he may be working it even harder just running it around depending on tires and axle gears. We've messed with this a bunch and even with the monster Setrab in the grill, a simple gear swap dropped the summer time trans temps on the freeway by 50 degrees.

 

[TonyArms]

Could be the lockup clutch in the toque converter has gone bad. Try driving in 3rd gear and see if it still overheats.

 

[mrblaine]

Did you splice the aux cooler into the driver's-side transmission cooler output line? That gives better cooling for the ATF than if the cooler is spliced into the passenger side where the 42RLE is concerned.

Essentially you are saying to cool the trans fluid with an aux cooler and then back into the radiator input, and then out to the return to the transmission? Do I have that right?

 

[B1Toad]

Question for those of you familiar with the Mopar transmission cooling system , is it possible that the cooler is restricted causing the bypass to open?

 

[Jerry Bransford]

Essentially you are saying to cool the trans fluid with an aux cooler and then back into the radiator input, and then out to the return to the transmission? Do I have that right?

No. The 42RLE ATF comes out of the radiator cooler on the driver's side. It's the 32RH whose ATF comes out of the radiator on the passenger side. At least that's what I said in my writeup at https://wranglertjforum.com/threads...-transmission-cooler-on-your-wrangler-tj.590/ which is what I always have to refer back to. It's also the side I connected my 42RLE's Derale cooler into.

 

[mrblaine]

No. The 42RLE ATF comes out of the radiator cooler on the driver's side. It's the 32RH whose ATF comes out of the radiator on the passenger side. At least that's what I said in my writeup at https://wranglertjforum.com/threads...-transmission-cooler-on-your-wrangler-tj.590/ which is what I always have to refer back to.

I was going by your use of the term "output line" which typically means the output to the radiator heat exchanger. Also why we don't use either of the cooler ports on the radiator to identify input and output from the trans. We use the ports on the trans.

 

[Marshall 55]

33's 4.1
Same as it has been for 10 yrs

What is your tire size and axle gear

What is your tire size and axle gearing?

 

[mrblaine]

33's 4.1
Same as it has been for 10 yrs

That isn't doing you any favors. That is the appropriate gear ratio for 31's, at a minimum you should be at least 4.88 and even better at 5.13's. That final gearing is taking a toll on the trans. A good temp gauge plumbed into the pan will give you a real time picture of what is going on.

 

[Marshall 55]

I need to know WHY it's getting hot

 

[B1Toad]

I need to know WHY it's getting hot

You can try the suggestion by Tonyarms, and you can check the temperature of the cooler and lines to make sure it's circulating. Those are two easy and free preliminary steps that I'd try. Also, a real gauge setup like mrblaine suggested is invaluable on any automatic, and something I'd not tow without.

 

[Jerry Bransford]

I need to know WHY it's getting hot

We're trying to help you, really. Did it start getting hot recently? After or before the aux cooler was added? Is there any mud or dirt covering the radiator or aux transmission cooler?

 

[Marshall 55]

We're trying to help you, really. Did it start getting hot recently? After or before the aux cooler was added? Is there any mud or dirt covering the radiator or aux transmission cooler?

It happened on March 1st while pulling my camping trailer. 160 from home the CEL came on. I pulled over and got the two codes (see attached). I checked fluid and end of dip stick was super HOT. I sat for 20 min then drove it with no light to a camp site. Next morning I dropped the pan no metal on magnetic changed filter then took it to shop to have them install auxiliary trans cooler and had them run a scan(see attached). I never went over 20 miles since the 1st time the CEL came on. I left the shop and on the way home the CEL came on after 30 miles. I stopped,cleared same codes sat for 10 min and went another 30 miles,then 60 miles then 40moles then made it home. I took the out yesterday with no trailer and made it 53 miles.

 

[Marshall 55]

Did you splice the aux cooler into the driver's-side transmission cooler output line? That gives better cooling for the ATF than if the cooler is spliced into the passenger side where the 42RLE is concerned.

Yes

 

[Marshall 55]

Could be the lockup clutch in the toque converter has gone bad. Try driving in 3rd gear and see if it still overheats.

What is confusing me is the fact that I can drive it for 50 miles and o ly stop for 10 min then go another 50 miles

 

[Jerry Bransford]

The old filter was still in good/non-ragged condition when you changed it? Grasping at straws here, just thinking if it was in bad condition/raggedy pieces could be blocking flow somewhere. If not my next guess is one of the solenoids inside the valve body isn't working and is blocking ATF flow.

Changing to the 32RH would be difficult since newer PCMs like yours don't have the ability to engage the 32RH's torque converter lockup mechanism.

I'd be thinking replacing the valve body or at least getting inside to examine the solenoid valves. It's definitely not that hard of a job. I had a problem with my 42RLE and ended up going completely through the valve body to clean it up and replace a few potential sources of problems for my 42RLE which had been stuck in limp mode. I had never been inside an automatic transmission before so it's definitely doable by someone at least comfortable with tools, has a 1/4 lb. torque wrench, and is willing to use the Jeep Factory Service Manual as a guide.

There are various sources of complete valve bodies around, eBay and Amazon are two sources. I'm not making a recommendation for this one but this is just one ad for one. https://www.amazon.com/Solenoid-Com...Transmission/dp/B0C4GZH8YH?tag=wranglerorg-20

This is what mine looked like once I had it ready for re-installation. I was shocked my 42RLE was ok after my inexperienced journey into its innards but it has been nearly 10 years and it is still running perfectly.

This is definitely not a job for the faint-of-heart but it's not technically difficult either.