I have heard rumors over the years of guys swapping their fluid and then having problems with their transmission.

Is that because they have burnt fluid that is clinging to the clutches, then the new fluid breaks off that crud and the crud gets stuck in places it shouldnt?

I dont know how many miles are on the fluid in my transmission ... and was about to swap it out , but then thought of this and it made me think.

Do most people drop the pan and swap the filter ... or just do the fluid swap without dropping the pan (with a machine)? I have heard rumors that a dirty filter actually filters better ... but I am pretty doubtful of that one.

Is that a shadetree mechanic tale , or is there truth behind it?

Should we use synthetics or just basic fluid?

Thanks ---

 

I don't see how it could hurt it, old fluid will kill it. My wifes Caravan had a vibration when th tcc locked, a condition called torque converter shudder. The fix was to change the fluid 3 x in a week. The first time I pulled the pan it was full of crap and probably would have failed by the end of the month, the second time was better and so on. That was over 60k miles ago.

 

Yes, it has been known to happen. The problem is, would the trans have been ok longer if the fluid hadn't been changed?

I would change the fluid and filter either way. If the fluid looks dark or smells burnt, at least you'll have some warning that you're probably going to be in for an expensive repair soon. Yes the new detergent additives in the new fluid can break loose things from the clutch packs and cause them to slip more- but if they're that bad it's just a matter of time anyway.

When I serviced the trans on my 95, the fluid came out an opaque maroon color, and me not knowing any better at the time thought that was normal for used fluid to look like that. The trans gave out a few thousand miles later. Would the trans have been ok if I hadn't changed the fluid? No. Lasted longer? Possibly...