4L 60E harsh shift

gbs · Dec 9, 2011

opened up the accumulator, piston spring was in three pieces plastic piston was cracked thru in three directions,cleaned out housing made sure holes were clear installed new spring and aluminum piston,also pulled servo piston cap found a brass shim about .100 thick under it don't know what it was installed for but removed it and replaced o-rings and seals,doesn't shift as hard as it did before but it is still to firm when it shifts from 1st to 2nd rest are ok what else could be the problem

Allan in NE · Dec 10, 2011

Just some ideas to help you along,

Those things are really picky about the piston and it's seal. Were both new? Aluminum pistons tend to wear egg-shaped at the hole.

Also, did you use the newer-style seal with the "raised" portion on the outter edge? The new piston and seal should really be quite stiff going down into it's bore. Did you use the proper spring? Install it correctly?

Now, if some shade-tree doctor has put a shift kit in this thing, it's never gonna shift right again without a full-blown blueprinting. Was the tall shoulder of the 4th apply piston of the servo installed in towards the tranny instead of out towards the cover? (dead give-away)

If so, and if the darned truck tries to lift the front end off the ground when shifting, I'd really be inclined to think someone has 'doctored' it.

Is the tranny throwing any codes? Is the TPS okay? Force motor?

All said and done, have you remembered to check that silly fuel filter? It trumps all shifting problems. You should be able to blow thru it with 'zero' effort.

Hope ya get 'er figured out,

Allan

4L 60E harsh shift

gbs

Member

Allan in NE

Well-known Member

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