burnt transmission fluid when engaged on 4low

[SpTrPi]

recently went off roading nothing serious just mud,,small rocks and potholes on 4high...then encountered a steep trail so i switched to 4low to try getting over it which i did but then smelled burnt transmission fluid...checked dip stick fluid is color brown...had it rest for a while went down the trail with 4high engaged,,no burnt smell then 4x2 all the way home...had my tranny fluid changed,,no dirt or residue or anything just color brown and burnt smell...no leaks also...what could be the reason for it overheating.?

i have a 2001 sport trac btw...thanks.!

 

[kmartin]

When was the last time you changed your ATF? The only reason I can think of is low on fluid, and/or got the fluid too hot that it wasn't lubricating properly anymore.

 

[SpTrPi]

just 2mos ago...ATF fluid level is ok,,i always check all fluids before going off roading...1st time it happened but now truck is much heavier than before b'coz of steel bumpers and winch...was thinking it's one reason for it to overheat...installed a fan on the cooler now then will see if it still overheats on 4low...