Just bought this 2003 with 160K miles on it. The only transmission fluid (TF) change information I have on it is the previous owner had it for 20K miles and didn't change it. It's in the shop for tie rod replacement and front axle work. Talked to the shop manager about the TF fluid, and he said "I don't recommend flushing it, it's likely that it will cause problems that will have you changing the transmission in a few months. Just top it up".
I've never heard this before and am wondering what to make of it.

 

Sounds like more horse**** to me by this tech.. What kind of transmission do you have?

 

This TB has the 4X4 transmission.

 

some people believe that flushing a dirty trans with clean fluid will loosen up debris (trans fluid has detergents) and this will circulate into passages and cause problems in the valve body or other circuits.
old trans flushing equipment use to reverse flush against normal flow direction and pressure pulse...stirring up crud. New exchange machines all the torque convertor pump to push the fluid out in the normal direction flow with no pressure pulses. flush is bad...exchange is ok.

I have old vehicles with 200 000kilometers and 250 000 kilometers that I bought used with no service history. both trans were running fine. I exchanged the fluid in both and had no problems. I suppose it could be possible to create an issue...never say never...has not happened to me.

Its all perspective...fluid has a life and wears out...leave it in long enough and you will have a problem.