tranny shifts hard when hot or under load...
 

Hello all,

My transmission shifts pretty smooth when cold (love the feeling); but hard (slamming/thumping) once the engine's hot (or tranny fluid is hot), or under load (light hill or with passengers) - especially the 3-4 shift. I've tried to adjust the vacuum modulator CCW one slot - it helps but I don't think it's gonna cure the problem.

Could someone please help ?

Any comments are greatly appreciated!
TIA,
Frank.

P.S: It's an '86

sjcruiser, don't know what year you have but try the link I have attached and scroll down to transmissions. Some good information (and pictures);)
CLICK HERE

>>The B2 band servo piston has been redesigned, reducing the loss of pressure during release as part of the 3-4 shift<<

Interesting fact... what's the symptoms when this happens ?
As stated above - the roughness is mostly in 3-4 shift. Another thing that I observed is that the economy gauge is pretty sensitive with throttle possition - on a moderate acceleration, it would move to bold red area (possible vacumm leak here ?)

Anyone ? Steve ?

Thanks again,
Frank.

I have this problem too- it's bloody annoying! When the car is really warmed up (after an hour or so of driving) the shifts are smoother again like when cold.
Very odd...