[regan wilson]

There are too many modifications to be done inside . It has to come apart . I run a Hipster brake . Nine years ago when I put my truck back together I did alot of research on this and one of my friends builds my transmissions . We have gotten it to where it survives pretty well . We usually tear it down once a year . Usually we replace a bushing or two maybe one or two clutches and steels . It is amazing how much stock TH400 parts can take . I can tell you alot of little tricks that will help it survive . Three good ones are, drilling out the center support bolt so more fluid can go to the second gear clutches , using a stock type wave plate in the case for second gear , and putting a good cross hatch on the sprag surface everytime you have it down .(these are for sprag survival) . Another important thing on a TH400 is high gear clutch clrearance ! Dont be afraid to put 100 to 110 thou of clearance in them . The reason for this is when the tranny is in low gear those clutches are turning 1.5 times engine speed backwards .