93' LX, transmission slips, after it warms up it's OK, the fluid needs to be changed. I have had people tell me it's not good to change the fulid becausethe newer fluidwill damage the clutches, something about the varnish built up, which I don't believe, hey it's slipping, change the fluid and filter.
Has anyone ever heard of this?

 

I have heard that if the fluid is burnt it may speed up the demise by changing the fluid.
Depending on age and condition, you may be able to extend the tranny's life a bit by cleaning it with AutoRX. Google it and try some. I use it in my engines with good results. Cleaned my rings to help compression, and small oil holes in lifters allowing them to expand, thus decreasing lifter tic.Much quieter now. It claims to clean valve bodies, seals, etc.

 

I am having a similar issue in
my 97 F150. When is is upshifting to OD
or 3rd the drive train ****ters like you were
running over rumble strips.
I understand that just a normal trans fluid
change may make it worse. However if
Mercron V is used it will help as it has friction
additives that will help the clutches in the
lock up torque converter.