My mechanic claims replacing the transmission fluid can cause unpredictable damage to the transmission. My Dodge dealer says it's actually necessary in order to keep the transmission in the best shape possible, as long as it's done using a pan and not by flushing. Who's right?

 

They both are. You have a high mileage Durango and if the transmission hasn't been serviced at regular intervals it may cause more problems after the service. I FINALLY had my 02 serviced at 175k and shortly after, my torque converter went out. Luckily that was all that happened.

SJ02

 

the dealer is correct, if you drop the pan change fluid and filter it wont cause any harm, if you take it to a shop they tend to flush the transmission bc its easier for them and cleaner to do but pumps high pressure fluid (and cleaning chemicals) through everythign which will damage seals.

as long as you refill with the correct fluid and do NOT FLUSH the transmission a fluid change will not hurt you

 

+1 Sharps

Just pull the pan replace the fluid with ATF+4 fluid only, adjust if necessary then button it back up. Now I can see Smok'ins point, only because the viscosity is such that it seals the imperfections which new detergents would clean out, but that's it because it surely not helping the transmission.

 

Smokin's point is exactly what my mechanic makes. This sounds like one of those cases that I just have to decide one way or the other and then live with the consequences, if any.

 

I'd just do a 'pull pan and change filter' job. You get to know the filter is good, get to see if there is any evil in the pan floor, and get to have a good look at the old fluid quality.