transmission got a little heated going over the Siskiyous.

[spin05]

Just got back from a california trip. On the way down while going over the Siskiyous southbound my transmission got up to a temp of 239 for about 3 or 4 minutes. Engine temp was 209 deg. Also at this max temp i felt a kinda of surging going on. Not like it was slipping thou. Was in tow/haul mod but only doing around 45 due to a semi blocking me. Was towing a 31ft trailer loaded down to around 9,000 lbs if i had to guess. Anything to worry about???? Got maybe 2k miles on the transmission fluid,filter,new solniod etc,etc. The rest of the trip the transmission never got over 218 deg. Temp readings are taken with a edge insight CTS monitor thru the computer. Kinda weird ,like there may have been a chunk of something blocking a path or something. Rest of the trip the transmission performed flawless. Would like to add that my fluid level is about a qrt over filled. Would this cause the surge?????

 

[SnoKing]

I wonder where the Edge Insight gets its temps. That is pretty hot of fluid in the transmission pan. Sounds like the TC was not locked up. Were you in 3rd gear? Why was the coolant running warm? Is it time for a rad boil out??? Was the fan clutch locked up aka roaring sound under the hood?

If a TC is locked up and things are working right you should not see high temps!

Chris

 

[spin05]

not sure what gear or if it was locked or not was in D with tow/haul mod on. It was a little muggy out but not hot. The siskiyous southbound first pass is long and steep so things are going to get heated when towing.

 

[SnoKing]

If things are working right, you should not see high temps. What is the past experiences been like? Seem like you have a underlining problem. Chris

 

[p-Bar]

It's a bit hot probably not much to worry about . That measurement is post cooler so a lot hotter coming out of the torque converter. Remember when the torque converter is not locked up you are making the connection with the transmission fluid very important as said above to make sure you are locked up . How many miles on the truck ? Is transmission stock? The tow haul button on 04.5 keeps it out of overdrive and changes the shift points. My transmission guy ran me up a wire so i can lock up in any gear , I also run a temp sensor before cooler so I see high temp but I want to know if I am cooking off my fluid or not.

 

[Motorhead]

I would think that at 45 mph, you would be in third or DIRECT on your trans. It might though been locking and unlocking as you changed throttle positions following the Semi thus the added heat. The stock converters are real slippery, in MY opinion. I would agree that a lock-up switch would help. Upper RPM's and lock-up are your friends for keeping your heat down on an automatic trans. Does your truck have the factory tow package that has the extra cooler?

 

[cerberusiam]

The CTS reads from the pan on the OE sensor, it may or may not be exactly correct as the signal is smoothed to what the ECU thinks it sees.

At 45 mph it was in drvie and the TC unlocked to get that hot. If the ECU thought it was hot enough to worry about it would have in D and it would slamming the lockup on to stop the heating. That is real noticeable when it happens. 45 mph is right on the verge of too slow for the gearing and load. At that point I would have gone to 2nd gear to get the rpms up and the TC locked. If it is working ok now probably no issues from the slightly hot temps.

If you do much of that a shift kit and getting rid of the drain back check valve plus a lockup switch is a good idea to have in lieu of a built trans.

 

[SnoKing]

What does the transmission fluid smell like? Because ATF+4 is a little dark to start with, color is not a good indicator. Chris

 

[spin05]

My understanding is the ATF+4 cant be judged by smell either. But will check it out tomorrow anyway. Somewhere i remember reading it was good at x tempature for x time and as you go up in temp the allowable minutes decreases before it breaks down. Can not find that thread now

 

[Motorhead]

Will the torque converter LOCK in SECOND gear? I thought the trans will only lock the converter in 3rd and 4th.

 

[SnoKing]

LOL, my DTT valve body does in conjunction with their smart controller. Chris

 

[JLandry]

From Service Bulletin 21-014-07, October 16, 2007:

Mopar ATF+4® has exceptional durability. However, the red dye used in ATF+4® is not permanent; as the fluid ages it may become darker or appear brown in color. ATF+4® also has a unique odor that may change with age. With ATF+4® fluid, color and odor are no longer indicators of fluid condition and do not necessarily support a fluid change.​

 

[SnoKing]

Drats! Hello Amsoil! Chris

 

[sag2]

My old motor home spent hours hotter than that. My high temp was near 300! I pulled it down at 20,000 miles because I thought it might need to be freshened up from all the heat. It was perfect, seals still soft, no burned clutch material at all. New converter, clutches and seals since I had them anyway and was still going strong when I sold it. I would not give it a second thought as long as you change the fluid fairly regularly.
Check out my post manual lock up with relays for info on how to make the manual lockup switch.

 

[BLoging]

from what I remember in tow/haul mode pushed on, the torque converter does not lock and it locks out the over drive (4 gear), if I remember right when reading the owner's manual!

 

[jelag]

Has anyone looked at one of the vendors web sight for the maximum temperature of the ATF +4 fluid... My BIL has both a larger pan and upgraded cooler to pull his 5er (15-16K) around the country.... and he's unhappy when he see's much over the 225-240* mark... he's picking up his temperature with a probe in the large finned pan....

 

[cerberusiam]

Mine will lock in 2nd gear manual with a low enough load, it will even lockup momenetarily in auto mode and totally botch the shifting pattern under certain conditions. AFAIK, with TH on an 04 it should lock the TC if the load is not to high, that is where it gets a little iffy. At 45 mphg it is right on the edge so depending on how good the TC is it may not lockup until higher mph.

ATF+4 is rated at 315 degrees fro 1500 hours and still retain the parameters the testing used, scar, wear, etc. What it does in the trans with contmaination of friction material and steel is another story. If the ECU did not turn on the trans temp light it had not hit 240 degrees where it is supposed to go into an aggressive lockup and save mode. Whether the transducer was reading temp correctly is another consideration as they the worst pieces in the whole trans for inconsistent operation.

At 209 coolant temp the fan was probably on full and if it was not perfect that will cause a surge in certain cases. That will directly effect the trans fluid temp also and if the speeds are slow enough and the air flow disturbed the trasn will get warmer than normal.

 

[JLandry]

Has anyone looked at one of the vendors web sight for the maximum temperature of the ATF +4 fluid.

The original technical paper which describes development of ATF+4 states it was tested for 500 hours at 155 degrees C (311 degrees F) and still retained acceptable performance criteria required by Chrysler.

You can read the full report HERE.

John L.

 

[mbirch]

I had a recent experience similar to spin05, also on a trip to California. It happened three times, always after towing my 9200 lb. 5er up very steep switchbacks for about 10-12 miles. I was going about 45 mph, I think I was in second gear and the transmission would shift into overdrive and the engine would lug down to about 1000 rpms. The third time it did this I pushed the tow/haul button off then back on, made no difference. I then mashed the throttle to get it to downshift, but then it just tried to shift up again into what appeared to be overdrive or lockup? The solution was to manually pull it into second gear, rpms went up into the power band and after getting to the next pullout I took a reading of the outside bottom of the transmission pan with a heat sensor, it was 137 degrees.
My transmission has been recently overhauled, I have a deeper aluminum transmission pan, a shift kit and a billet steel torque converter just fyi. My transmission guy is thinking much like Cerberusiam that it was sensing high fluid temps and was attemping to cool itself down by locking up. But if shifting into second would also do that, why did it not stay in second gear to start with? I guess I need to install a transmission temp gauge.

 

[BIGNASTY]

,,,,,,,,,,,,,,,,,,,,,,,