Heading up to Markleeville going up grades from sea level up to 7500 (tahoe-hiway 50) on the road noticed my transmission temp gauge (diy) usually at 150-170 started climbing up to 210-230. Temp went up very fast, maybe 45 seconds from 180-220. As soon as the road would level off, the temp would go back down. Was traveling about 60-65 mph.
While offroad over the weekend even when crawling over obstacles never saw over 210.

Ques: does the temp climb mean this is the beginning of transmission slipping? Fluid looks like it should bright red. No other issues other than after turning off the O/D button when I re-engage the overdrive button it feels like a rough shift as it engages.

What could be causing this?

Thanks Josh


Ok, here are my trucks specs.
miles: 160k
1998-SR5-3.4 with 2nd gen S/C urd 7th, and 2.2 pulley. Oh yeah and meth above 6psi.
Trans: 4spd auto w/ Level 10 valve body upgrade.-RV size trans cooler.
Gears 4.88s
Tires 295/75-16BFGs
added weight- front and rear plate bumpers-swing out w/tire on rear, winch in the front-full amour including gas tank.

 

Just a shot in the dark but could it be the torque converter isn't locking as it should? From what I can remember(I have a 5spd now) the torque converter should lock after 45mph. Its uses a solenoid that could be toast.

Good luck

 

I see the same thing with mine. Temps climbing quickly is normal when going uphill.

 

As was said, if the ECU sees enough load it will unlock the converter. This will cause temps to climb very fast.

If you don't already get the biggest transmission cooler you can fit.

 

Thanks for the replies.
I'm already running a RV size tranny cooler and this is the first time it has done this.

I need to do some looking around on my end when I get a chance. I know the tranny cooler lines still run through the rad, yes this is the way the PO ran it. Since I wasn't seeing a pink milkshake I figured the extra cooling couldn't hurt.

Really curious why re-engaging or turning the overdrive button "on" is so rough regardless of trans temp.

As an aside, anyone know what temp the tranny has to get to, to trip the dash light that deals with AT temp?
Could my sender/gauge be messed up? -doubtful.

Thanks again

 

All the OD button does is enable/disable the 4th gear and converter lockup.

Were you towing anything? Try leaving OD on next time if you are not towing anything and see if it is better. I have even towed with OD on without an issue (forgot to turn it back off after filling up with gas and drove a few hours like that with a majorly overloaded trailer).