Transmission temp scare

[lfhoward]

I was towing a trailer up the mountain just out of Jim Thorpe, PA today. It’s a long steep climb and I didn’t get any faster than 30-35 mph.

I have a Scangauge so I watched in horror as my transmission temperature climbed to very uncomfortable levels.

By the time I got to the top, it was about 242°. I knew this was bad so I pulled over and put it in Park. Bad idea. Without air flowing across the transmission cooler radiator, the temp spiked up to 264° or 268° (can’t remember which). At that point I decided it was better to start driving. Luckily there was a flat plateau in front of me and the temp came back down.

There were no burning smells and the transmission light never came on. But dang, 268°! I’m sure my fluid needs changing now. Hopefully I didn’t damage my transmission. It’s never been above 220° before today. Luckily it still behaves well.

I’m looking for advice on what to do next. I’m thinking, change the ATF as soon as possible. Also, I am thinking I should add an auxiliary transmission cooler to help the stock one. What else?

Thanks!

 

[tommudd]

Time to think about that regear as well , would help a lot
I know I know transmission cooler is cheaper , but..........

and change the fluid

 

[lfhoward]

Probably need both a transmission cooler and a regear.

The regear I could get done for $2200, add $1000 more with TrueTracs installed...

The transmission cooler is like two orders of magnitude less expensive, lol. Definitely doing that and changing the ATF+4 fluid this week.

 

[LibertyTC]

I think the Trans temp light turns on around 270F & 268 was real close.
The owners manual recommendation is to pull over, throw it in Neutral and rev it a bit till light goes off.
With my KJ same thing as above, but I lift the hood first, to get rid of all that under hood heat.

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New ATF +4 please, & cooler, ya very helpful when towing especially in summer/mountain hills.

 

[lfhoward]

Thanks TC. Appreciate your feedback too. I was wondering what the right thing to do in the moment was when it was overheating, so thanks for the procedure from the owners manual.

I just checked my spreadsheet that I keep with all the maintenance items and mods for my Liberty. The last time I changed the transmission fluid was at 133906 miles back in 2016. Now it’s 4 years and 38,000 miles later. Definitely time to change it again anyway.

 

[lfhoward]

I’m about 100 miles from home with my trailer and Jeep. Can the fluid change wait until I return, or would I be risking my transmission? It’s mostly Interstate driving and coming from the mountains down to sea level. So far no driveability issues driving here locally.

Anyway, not sure I can get the fluid change done close to where I am. And we have to drive home tomorrow anyway.

 

[LibertyTC]

As long as the fluid is still clean & does not smell burnt in any way, I think you will be fine until u get back home.
Make sure you also do the interior trans filter w/ the fluid pan drop.
Does your 08 KK have a dipstick where you can add some fluid?
If so now would be a good time to add a tiny bit of seafoam trans tune, that will help a lot to clean & protect, if you have some room to add when hot.

• TRANS TUNE helps fluid systems work smoother and last longer.
• Dissolves and liquefies harmful gum and varnish buildup in fluid.
• Cleans and lubricates valve bodies, shift actuators and solenoids.
• Controls moisture.
• Safe for conventional and synthetic fluids.

 

[lfhoward]

Hi TC,
Unfortunately the KK has no dipstick, just a cap that says “Dealer Service Only.” I can’t check the level or the condition of the fluid.
On the other hand, it was only above 140° For about 5 minutes, and above 160° for only 2 minutes.

 

[lfhoward]

Made an appointment for Thursday at a mechanic I trust to have the trans fluid & filter done, and install a transmission cooler. They will have a good look at everything, including the radiator (incorporates the stock trans cooler), which is original and 13 years & 172K miles old. Hopefully that is fine. Don’t want things to get too pricey.

 

[LibertyTC]

Understandable to keep things reasonably priced.
Wish you the best, but honestly I'd also want to consult a dealer to obtain a dip stick of some sort.
Here is the listings about possible solutions to the dipstick issues, and also correlation to temp charts etc.
https://www.google.com/search?client=firefox-b-d&q=jeepkj.com+no+transmission+dipstick

 

[lfhoward]

Thanks TC. Just wanted to report I made it home fine pulling the trailer. Have an appointment at the mechanic for Thursday.

 

[LibertyTC]

Excellent, glad you made it home without issues. Look forward to hear how things go then on Thursday.
Feel free to post a few pics, cooler install, I think your jeep will be happy again soon!

 

[lfhoward]

Jeepy is at the shop getting fluid, filter, and an auxiliary cooler installed.

The old fluid was slightly discolored and had an odor to it, so it was definitely time to change it. My mechanic doesn’t think there was any damage from the overheat, but thinks that an aux cooler is a good idea with all the towing we do.

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[uss2defiant]

might want to add a drain plug to your pan while he's at it.

 

[LibertyTC]

Or consider the PML 42RLE machined aluminum pan with drain plug+ 1.25 quart more fluid=bonus.
The stamped steel trans pan stays hot all the time.
Aluminum pan dissipates heat & stays way cooler by far.

 

[tommudd]

FROM EXPERIENCE, IT IS STILL BETTER TO REGEAR THAN BANDAGE IT WITH A COOLER

 

[lfhoward]

Tom, you’re not wrong. It needs to be done, but can’t just yet. Got to baby it a little longer.

 

[lfhoward]

Got the Jeep back. Emptied every pocket. She runs smooth though.

I’ll grab a photo of the new transmission cooler tomorrow and post it up.

 

[lfhoward]

Some photos of the transmission cooler. I’ll report back later about how much difference it makes.

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Hoses attach on the drivers side.

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A little better view from the passengers side of the grille.

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[duderz7]

Or consider the PML 42RLE machined aluminum pan with drain plug+ 1.25 quart more fluid=bonus.
The stamped steel trans pan stays hot all the time.
Aluminum pan dissipates heat & stays way cooler by far.

I'd like to get one of these, who's got the best price?