Engine/Transmission (1998.5 - 2002) transmission temp @ 220???

[stownsend]

Just got the transmission temp probe hooked up using the Jannetty probe manifold. This works pretty well. It was easy to install, but make sure to put teflon tape on every threaded part, otherwise it will leak!



I noticed that while driving around town in relatively heavy traffic, the temp went to 220. Normally if traffic is flowing, it never goes above 170. Does that sound normal? That temp (220) seems high to me.



Steve

 

[KLockliear]

Is that in the pan or in the cooler line?

 

[bmoeller]

My guess is in the hot line. Mine can get that hot if I let it, in town.



If you are leaving it in gear at stoplights, put it in neutral to take the load off. Having the probe in the hot line, it will be hotter than in the pan and get there quicker. It comes straight out of the torque convertor. That thing makes most of the heat.

 

[stownsend]

The probe is in the hot line.



Yes, I am leaving it in gear. Thanks for the advice. Next time, I will try putting it in neutral to see how it affects the temp.



Steve

 

[y-knot]

Sure makes for a strong argument to use synthetic ATF. With conventional AFT the life of the fluid is cut by 50% for each 5 degrees of temperature after 190. The scenario breaks down like this. Normal life for ATF is 30,000 miles at temps under 190. Go to 195 and life drops to 15,000. Got to 200 and it drops again to 7,500 miles. Go to 205 and your now down to 3750 miles. Go to 210 and you need to change fluid at 1,875 miles, so on and so no. Conventional fluid breaks down and burns, the damage takes place once the temperature hits the prospective temp, and the fluid does not regenerate, so once and done for it. The parts usually get coated with a varnish like resin, which makes them stick,hang,slip, or react slower then normal. The cycle is self perpetual, which means once this all starts, it affects the transmission and it's parts to the point that they continue to cause more and more damage. Clutch packs slip and build more heat, bands slip and build more heat, parts hang or react slowly causing heat and wear issues. The best defense is a good offense, so avoid situations that will build heat. Allow oils to cool after hard use, and check fluids often for discoloring and burnt smells. Change if discolored or if you know you overheated it. And if possible use synthetic ATF to avoid all or at least most of this mess.

 

[KLockliear]

DTT has told us the limit in the cooler line is 250*F for standard fluid. In the pan, this would equate to around 210*F.

 

[John - K5AWO]

At 275* F, oil will congeal when it cools down. had it happen in Colorado pulling a trailer that was too big behind a car with to tall of a gear. transmission temp gauge went to 278 in the output line to the oil cooler.



The next morning when I pulled the stick to check oil levels, it was real thick. Drained it right there and put in fresh transmission fluid.



This was back in 1978, oils are better now than then, but not by that much. Synthetics are the way to go.