Engine/Transmission (1998.5 - 2002) transmission temp high?

[vaicase]

does anyone know what causes high transmission tempature it got to 250 degrees towing about 7000 lbs. then i drove it empty and it still got to 200 so i put a hayden cooler on it i got the biggest one they make. it only dropped about 15 degrees to 185. what could be causing this. the truck shift firm and drives good. the fluid is nice and red. it takes about 10 miles to get hot. it is not pluged,i took the return line off and it gets good flow. i need a transmission person. or maybe someone else has an idea. also i drove it in drive and overdrive same thing. thanks

 

[SEmerson]

Sounds like the tc is not locking.

 

[hammersley]

BINGO! You need to install a manual lock up of TQ - and get a better TC that doesn't cause as much "oil shear".

 

[hammersley]

How many miles on truck???? Mods?????

 

[vaicase]

the truck has 209000 miles on it. the fluid is red. and i think the t. c. is locking because with 31 inch tires and 3. 55 gears the r. p. m. is 1500 at 55mph,the only mod is 4inch catback exhaust and a gutted cat and a after market downpipe. the rpm is 2200 at 55 in 3rd then it really drops about 700 rpm but it must shift into lockup at the sametime as overdrive. thanks

 

[TnLRacing]

where is your temp probe?

 

[hammersley]

With 167,000 miles on my truck - 2 weeks ago - I had my transmission done..... I took her into the shop at 11:30 and the Tech told me that by 5:30 when they tried to take the TC out - it was to hot to touch WITH BARE HABDS!!!! THAT WAS 6 HOURS LATER!

 

[Lsfarm]

sources of heat

Hello Viacase. There are three main souces of heat: From the engine block, [we can forget this one] From the Torque converter shearing the ATF, or from slipping clutches.



If you were slipping clutches, then you would have burnt ATF, very quickly. so I think you can discount this one too.



So the remaining source is the Torque converter. It will make NO HEAT if it is locked. In the Dodge trans with the heat probe in the hot line coming out of the trans before the coolers, the temp will be 150* when in third gear locked or OD locked.



The only way to get the temps you are seeing is to pull heavy with NO lockup. Or a lot of stop and go with no lockup.



Ford Torque Converters are a problem, so I would look in that direction.



Where are you reading the trans temp, and is the guage accurate??



Good luck, Greg L.

 

[vaicase]

well we were all wrong. on the fords there is a checkball in the fitting for the return line. i removed it and no more overheating. so keep this in mind,maybe it will help someone else. thanks

 

[OTRPU]

Is there an optimal temperature for the auto transmission fluid to be at? I had a second cooler added, got the ATF Stage IV w/TransCommand when rebuilt. Standing on the dam thing up hill with all kinds of heavy trailers transmission temp never reaches 150. Now if I let it idle or driving around the city stop'n'go in construction jams I've seen it near 180. But never heats when running the hills under a load. Wondering if it can be TOO cool?



Cheers,

Steve J.