All automatic transmission JK owners should read this! regarding overheating trans
09-22-2010, 02:30 PM
#11
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I installed an aftermarket cooler. Took an hour of my time and $50. Way better than dealing with the dealer.
I got to test it out right after installing it. I was towing a 2200 lb. trailer up the mountains here in Colorado. The worst hill is the one right outside Denver going up I-70. The outside temp was 91F, and my engine temp had climbed to 3/4 on the gauge. My speed was 35mph (speed limit was 60- the 3.8 is way underpowered) and I did not get the HOT OIL message. I can't say what the tranny temps were (installing a gauge is on my to do list) but the tranny did not overheat.
Patrick
I got to test it out right after installing it. I was towing a 2200 lb. trailer up the mountains here in Colorado. The worst hill is the one right outside Denver going up I-70. The outside temp was 91F, and my engine temp had climbed to 3/4 on the gauge. My speed was 35mph (speed limit was 60- the 3.8 is way underpowered) and I did not get the HOT OIL message. I can't say what the tranny temps were (installing a gauge is on my to do list) but the tranny did not overheat.
Patrick
09-22-2010, 02:36 PM
#12
JK Super Freak
Wow!! All the non-real Jeepers unhappy with their overheating trasnmissions. I guess we all need to do the Jeep community a favor and trade them in for Hondas, eh? 
1-800-247-9753
I just called Chrysler to voice that my death wobble (which they claimed to have never heard of- despicable) and overheating trans need to be resolved and the dealer's not doing it. Apparently it's guaranteed that I'll get a return call within 24 hours. We'll see. I have a reference number for the call.
And yes, TJ, installing one is extremely easy, cheap and effective. BUT, even if the dealer installs it themselves, it can void the lifetime warranty. Which is why I want THEM to do AND I want it paid for and in writing that the lifetime warranty will be honored. Why? Because my trans has already overheated a few times and is thus likely to burn out in the future. When it happens, I'll need that warranty. That's the kicker right there. If it's already overheated, it's possible that damage has been done. Knowing that, you need to protect yourself for the future when it craps out. I'd rather let it crap out and get a new one, then install the cooler BEFORE it ever overheats.
1-800-247-9753
I just called Chrysler to voice that my death wobble (which they claimed to have never heard of- despicable) and overheating trans need to be resolved and the dealer's not doing it. Apparently it's guaranteed that I'll get a return call within 24 hours. We'll see. I have a reference number for the call.
And yes, TJ, installing one is extremely easy, cheap and effective. BUT, even if the dealer installs it themselves, it can void the lifetime warranty. Which is why I want THEM to do AND I want it paid for and in writing that the lifetime warranty will be honored. Why? Because my trans has already overheated a few times and is thus likely to burn out in the future. When it happens, I'll need that warranty. That's the kicker right there. If it's already overheated, it's possible that damage has been done. Knowing that, you need to protect yourself for the future when it craps out. I'd rather let it crap out and get a new one, then install the cooler BEFORE it ever overheats.
09-22-2010, 02:41 PM
#13
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Explain to me how installing an external cooler on a tranny that is known to overheat is going to void the warranty. Is this what your dealer told you? Or did you just hear it on the net?
09-22-2010, 02:45 PM
#14
JK Super Freak
It's what my dealer told me, several times. They said that if the trans craps out down the road and they find that the trans has been modified, they have no proof that the installation was done correctly. Makes sense, actually. What if the person installing it didn't compensate the added volume by adding more oil and it ran low for a period of time? The stupid part, though, is that they won't honor the warranty EVEN IF THEY INSTALL IT, because it's not OEM. Just like factory lifts can void a warranty. Unfucking believable, eh?
09-22-2010, 03:19 PM
#15
JK Super Freak
being a new automatic owner.. my previous 3 jeeps were all 6 speeds.. (1 TJ and 2 previous JKs). I have noticed the cause of the overheating...
automatic transmission torque converters by nature make LOTS of heat.. modern automatics are outfitted with Locking torque converters.. so effectively the converter is "locked out" and there is direct connection from engine to transmission input shaft similar to when a clutch on a manual is let out and engaged for driving....
the Jeep automatic is a 4 speed overdrive transmission with a locking torque converter..
like any transmission when you need a little extra power to climb a hill or to pass, etc you need to downshift your gears... in a manual you downshift and go.. the Jeep automatic plays a trick instead...
if you need just a little extra power, the jeep will leave the transmission in 4th overdrive gear and will simply unlock the torque converter.. which will raise the RPMs on the engine about 500-600 so that you are making a little more power from the engine.. (into its power band)...
this is great for a real short time and works good.. however the trans is making LOTS of heat during this time.. the computer on the jeep is not programmed smart enough to re-lock the transmission until you let down on the throttle requiring less load from your engine... instead it continues to make heat until it overheats....
the way it SHOULD work is that the transmission would recognize a couple things:
1] that it would see an extended time of unlock converter.. and make a downshift to 3rd gear and then re-locl the converter and run in 3rd till you no longer need the extra power
2] that it could do the above if it notices the trans temp is rising too high..
I am confident that this would alleviate some of the issues with these transmissions.. this would all be a computer flash change and not need any hardware...
the other thing would be that they could allow converter engagement in 2nd gear as well for those that get hot oil when offroading and never make it to 3rd gear where the converter can lock-up....
whats funny is the old GM 4L60E transmission from the early 90s would lock its converter solid if it overheated....
-Christopher
automatic transmission torque converters by nature make LOTS of heat.. modern automatics are outfitted with Locking torque converters.. so effectively the converter is "locked out" and there is direct connection from engine to transmission input shaft similar to when a clutch on a manual is let out and engaged for driving....
the Jeep automatic is a 4 speed overdrive transmission with a locking torque converter..
like any transmission when you need a little extra power to climb a hill or to pass, etc you need to downshift your gears... in a manual you downshift and go.. the Jeep automatic plays a trick instead...
if you need just a little extra power, the jeep will leave the transmission in 4th overdrive gear and will simply unlock the torque converter.. which will raise the RPMs on the engine about 500-600 so that you are making a little more power from the engine.. (into its power band)...
this is great for a real short time and works good.. however the trans is making LOTS of heat during this time.. the computer on the jeep is not programmed smart enough to re-lock the transmission until you let down on the throttle requiring less load from your engine... instead it continues to make heat until it overheats....
the way it SHOULD work is that the transmission would recognize a couple things:
1] that it would see an extended time of unlock converter.. and make a downshift to 3rd gear and then re-locl the converter and run in 3rd till you no longer need the extra power
2] that it could do the above if it notices the trans temp is rising too high..
I am confident that this would alleviate some of the issues with these transmissions.. this would all be a computer flash change and not need any hardware...
the other thing would be that they could allow converter engagement in 2nd gear as well for those that get hot oil when offroading and never make it to 3rd gear where the converter can lock-up....
whats funny is the old GM 4L60E transmission from the early 90s would lock its converter solid if it overheated....
-Christopher
09-22-2010, 03:36 PM
#16
JK Super Freak
"the way it SHOULD work is that the transmission would recognize a couple things:
1] that it would see an extended time of unlock converter.. and make a downshift to 3rd gear and then re-locl the converter and run in 3rd till you no longer need the extra power
2] that it could do the above if it notices the trans temp is rising too high.."
Then you are not a real Jeeper and you should do us all a favor and sell it and go away. You should love your overheating transmission. If you don't love your overheating transmission, you are a Jeep hater and should burn at the stake.
1] that it would see an extended time of unlock converter.. and make a downshift to 3rd gear and then re-locl the converter and run in 3rd till you no longer need the extra power
2] that it could do the above if it notices the trans temp is rising too high.."
Then you are not a real Jeeper and you should do us all a favor and sell it and go away. You should love your overheating transmission. If you don't love your overheating transmission, you are a Jeep hater and should burn at the stake.
09-22-2010, 03:55 PM
#17
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"Overheating transmissions....It's a Jeep thing, you wouldn't understand."
And it's comforting to know that Jeep is looking out for it's international owners but doesn't give two shits about it's American owners.
And it's comforting to know that Jeep is looking out for it's international owners but doesn't give two shits about it's American owners.
09-22-2010, 05:23 PM
#19
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Good stuff! Are you going to be thrown under the bus for not accepting that your Jeep overheats, though, like I've been? Shouldn't you just accept the overheating transmission as a Jeep thing? You're not a real Jeeper because you got it fixed!
My Jeep's going in tomorrow for the auto trans; I'll mention the overseas thing. My dealer claims to have NEVER heard of a single JK with an overheating auto trans. They'll also look at the leaks and stuff. I'll have quite the list. 
And I don't need it back 'til next week so I'll be quite the dick.
Shouldn't you just accept the overheating transmission as a Jeep thing? You're not a real Jeeper because you got it fixed! My Jeep's going in tomorrow for the auto trans; I'll mention the overseas thing. My dealer claims to have NEVER heard of a single JK with an overheating auto trans.
They'll also look at the leaks and stuff. I'll have quite the list. And I don't need it back 'til next week so I'll be quite the dick. 
09-22-2010, 05:36 PM
#20
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I installed an aftermarket cooler. Took an hour of my time and $50. Way better than dealing with the dealer.
I got to test it out right after installing it. I was towing a 2200 lb. trailer up the mountains here in Colorado. The worst hill is the one right outside Denver going up I-70. The outside temp was 91F, and my engine temp had climbed to 3/4 on the gauge. My speed was 35mph (speed limit was 60- the 3.8 is way underpowered) and I did not get the HOT OIL message. I can't say what the tranny temps were (installing a gauge is on my to do list) but the tranny did not overheat.
Patrick
I got to test it out right after installing it. I was towing a 2200 lb. trailer up the mountains here in Colorado. The worst hill is the one right outside Denver going up I-70. The outside temp was 91F, and my engine temp had climbed to 3/4 on the gauge. My speed was 35mph (speed limit was 60- the 3.8 is way underpowered) and I did not get the HOT OIL message. I can't say what the tranny temps were (installing a gauge is on my to do list) but the tranny did not overheat.
Patrick