Over Heated Tranny: Update 4/21

Fulltimer · **Posted:** Sun Apr 18, 2010 7:10 pm

Saturday my locale Jeep club had a benefit poker run. It got up to 80* and the sand burned my bare feet! Any way, going through the route my tranny over heated 2 times. The trail section was deep sand and I was in 4WD and 1st. gear. My attempt to keep the tranny in 1 gear worked but it still over heated. The aux. electric fan did NOT come on until after it had over heated the 2nd. time. Then it came on for about a 1/2 min. each of the 2 times. The KJ didn't seem to be working all that hard and the engine never did over heat.

I assume there is a heat sensor that turns on the electric fan. Intermittent sensor frailer? There was no code. Just the idiot light!

Terry

mag03kj · **Posted:** Sun Apr 18, 2010 7:57 pm

Odd bc mine didnt do any of that at the M&G lol and i was O/D locked out and 2nd gear turning 4000rpms or more at times with the a/c on full blast too!

tjkj2002 · **Posted:** Sun Apr 18, 2010 8:11 pm

4hi or 4low? Should always be in low for wheeling,more so if you have the 42RLE.

Might want to check the e-fan relay also.Time to be looking at getting the trans serviced,high heat kills ATF fast.

Fulltimer · **Posted:** Sun Apr 18, 2010 8:46 pm

tjkj2002 wrote:

4hi or 4low? Should always be in low for wheeling,more so if you have the 42RLE.

Might want to check the e-fan relay also.Time to be looking at getting the trans serviced,high heat kills ATF fast.

It was 4Lo and I was thinking about that fluid too. Hot 2 times = bad news. Maybe I should just replace the relay and sensor to be on the safe side?

Terry

Budke · **Posted:** Sun Apr 18, 2010 9:06 pm

tjkj2002 wrote:

4hi or 4low? Should always be in low for wheeling,more so if you have the 42RLE.

Might want to check the e-fan relay also.Time to be looking at getting the trans serviced,high heat kills ATF fast.

Why 4lo? I usually use 4hi

ridenby · **Posted:** Sun Apr 18, 2010 9:41 pm

Budke wrote:

tjkj2002 wrote:

4hi or 4low? Should always be in low for wheeling,more so if you have the 42RLE.

Might want to check the e-fan relay also.Time to be looking at getting the trans serviced,high heat kills ATF fast.

Why 4lo? I usually use 4hi

Lower gear relives stress/strain on transmission,auto is always slipping to begin with.

stumpjumper_09 · **Posted:** Sun Apr 18, 2010 9:43 pm

If you has the choice of carrying 500# up the side of a pyramid on your back or using a reduction pulley system which one would you choose? That is kinda the way your engine and tranny feel about 4hi vs. 4lo the gear reduction helps compensate for the added resistance of the Sand mud rocks...

mag03kj · **Posted:** Sun Apr 18, 2010 10:04 pm

Well i thought 4low locked all 4 together....and 4hi was sorta like just a semi lock??

stumpjumper_09 · **Posted:** Sun Apr 18, 2010 10:48 pm

mag03kj wrote:

Well i thought 4low locked all 4 together....and 4hi was sorta like just a semi lock??

In the kj the only thing that changes when you put it in 4lo is an additional gear reduction in the transfer case.

tjkj2002 · **Posted:** Sun Apr 18, 2010 11:04 pm

stumpjumper_09 wrote:

mag03kj wrote:

Well i thought 4low locked all 4 together....and 4hi was sorta like just a semi lock??

In the kj the only thing that changes when you put it in 4lo is an additional gear reduction in the transfer case.

Yep...............

In 4hi the F/R outputs are normal speeds,in 4low(stock KJ) the F/R t-case outputs have a additional 2.72:1 reduction which relieves alot of stress on the engine and trans.

JL Rockies · **Posted:** Sun Apr 18, 2010 11:26 pm

If you're treading lightly, you should always be in 4 lo on the trails.

phxtoad · **Posted:** Mon Apr 19, 2010 12:40 am

Check the pan for leaks asap. Mine developed a leak when I overheated (in 4 hi by accident). Lesson learned!

dieselenthusiast · **Posted:** Mon Apr 19, 2010 1:01 am

Fulltimer, you may want to look at the new aluminum trany pan with temp sender.

viewtopic.php?f=1&t=40061

KJ 119 · **Posted:** Mon Apr 19, 2010 3:58 pm

dieselenthusiast wrote:

Fulltimer, you may want to look at the new aluminum trany pan with temp sender.

viewtopic.php?f=1&t=40061

No offense,but I would get a trans cooler before I would wheel with an Aluminum pan.
If I had one at the ECS last year I would have been up the creek halfway through the first trail,instead of a smashed steelie and able to carry on.

Fulltimer · **Posted:** Mon Apr 19, 2010 7:16 pm

Bub, I have a tranny cooler. :shock:

The aluminum pan is protected by the skid plate. That is unless you bash that skid plate really bad...like someone I know did! Who could that have been Bub? :-)r

Terry

dieselenthusiast · **Posted:** Mon Apr 19, 2010 10:01 pm

Fulltimer wrote:

Bub, I have a tranny cooler. :shock:

The aluminum pan is protected by the skid plate. That is unless you bash that skid plate really bad...like someone I know did! Who could that have been Bub? :-)r

Terry

Hey Bub, that aluminum pan is much stronger than the stock steel one. :goink:

KJ 119 · **Posted:** Mon Apr 19, 2010 11:12 pm

tjkj2002 · **Posted:** Mon Apr 19, 2010 11:34 pm

Just remember the KJ's with a 42RLE have a stand alone trans cooler which can not deal with temp spikes as well as a in-radiator cooler can.And yes with a stand alone cooler you can still overheat the trans when the engine overheats.

stumpjumper_09 · **Posted:** Tue Apr 20, 2010 1:56 am

I bet there is Bedliner in the tranny cooler :SOMBRERO:

dieselenthusiast · **Posted:** Tue Apr 20, 2010 9:32 am

In other words, Troy is saying that Fulltimer can buy a 2002 Jeep Liberty radiator (with the built-in cooler) and have it installed in his 2005 KJ. This would help control the temperatures spikes.

Over Heated Tranny: Update 4/21

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