4r100?

[64rarebird]

Hi been reading many many pages on the poor shifting on the 4r100 Trans, having a issue with my 97 7.3 have swapped in a 2000 model year engine and trans have had the ecm reprogrammed installed the on/off tcc valve installed e40d shift solenoids and accumaltor valve body updated but still having a intermittent harsh 2to3 or 3 to 4 shift feels like the transmission is going to jump out of the truck also have a very good scanner and no codes? Any ideas on where to go next? Should note Trans shifts good when easy on the throttle but when trying to accelerate guicker it holds the shifts to long high in the rpms causing the harsh shift .Please help this is driving me nuts!

 

[64rarebird]

Should also note the Trans is a tested good unit worked perfectly in the truck it was removed from

 

[IDIoit]

when I had issues with my 4R100, it turned out to be the jumper wire from the trans harness to the trans with a BD exhaust brake.
a exhaust leak melted the connector.

is your OD light flashing?

 

[64rarebird]

No overdrive light flashing and no codes

 

[trackspeeder]

What was done to the accumulator body? The issue could be with the accumulator valve.
I would do a pressure test to see what is going on.