I recently rebuilt my TH400 with the help of a friend who knows them pretty good. He is not available for me to ask, so I thought I would turn to the board for some help. The transmission has been operational for about 2 1/2 months now, and has about 100 hours on it or so. The symptoms I am experiencing are a really mushy 2-3 shift. Imagine if you will turning about 4000 RPM and shifting 2-3 and it's like slipping a manual clutch for about 3-5 seconds. If I drop the RPM, it will actually help it shift, but that's just unacceptable. This happens whether I shift it manual, or put it in drive and try to let it do it. I haven't played with the Vacuum modulator thing yet, which may be my problem, but then I don't know The 1-2 shift happens quick and is firm, usually around 2000 RPM, unless I'm really on it or shifting it myself. My TH400 is built with the following: Hughes Performance Premium Race rebuild kit W/ Kolene steels and Kevlar bands TCI Streetfighter Manual/Auto Valve Body Forward pattern TCI 2.75 1st 1.57 2nd Low gear planetary TCI 34 element intermediate Sprag Torrington rear output bearing from a TH350 Adjustable Modulator Custom Block off plate for downshift solenoid Hughes Performance 12 2000 stall Heavy duty converter Deep Aluminum pan I am currently running Castrol type F transmission fluid upon the recommendation of Hughes Performance. Any help or direction to attempt to correct this would be greatly appreciated. Thanks in advance,
Bill, I'm just winging it here but you might check the detent and be sure the selector is fully engaging each gear, not riding between teeth. You can pull the pan, put the linkage back on the case and check it when selecting gears from inside.
