Hey guys, what tools do I need for th400 rebuild? I'm gonna need a rebuild kit, too. Any suggestions?

Alexander

Snap ring pliers, piston spring depressor, bushing drivers, an arbor press is not necessary but real nice for installing bushings, pump alignment tool, flat rock, inch lb. torque wrench, sockets, scribe, screwdrivers, scotchbrite, speed handle, hammer, scraper, trans gel, a little ATF.

You'll need to take your time especially installing the pistons into the drums. If you find yourself doing more than one or two trannies, I'd urge you to invest in the piston lip seal installer tools. They knock install time down to nothing compared to using wire/feeler gauges. Also you'll need to have a dial caliper and dial indicator to measure clearances and end play. There are a few critical items in there to watch for. The rear band/reaction carrier interface is one. If you find the carrier surface badly scored up and have to machine/replace it (and possibly the band....) you'll need to pay CLOSE attention to the rear servo piston apply pin length. Kent-Moore makes a nice tool, but IMO it's far too expensive for most of us out there, even myself who does a LOT of Turbos. All you need to do is install the rear internal components up to the point of installing the center support, but leave the support out. Then install the rear servo assembly and look down in the trans while it's stood up on end, and see if there is sufficient clearance between the rear band and the surface of the reaction carrier where it applies around. If it's too snug, remove the servo and LIGHTLY grind the band end of the apply pin. Go SLOWLY when you do this as it's far easier to remove metal than add it back, lol. You need to have enough clearance for the reaction carrier to freely rotate inside the band. If it drags, the carrier and band will burn up quickly. You'll find most replacement rear bands will require a slight bit of grinding on the apply pin for things to fit. It's also very easy to pitch the OEM rear thrust/shim parts, and use a drum bearing from a TH350 to replace them with. This gives you a Torrington bearing for rear thrust, which is nice. Up front the OEM fiber thrust washers are fine, since there's no thrust loading in front of the center support in those trannies. They do make varying thicknesses of the fiber thrusts though to accurately set front section end play. In the rear just use thin shim washers to set rear endplay along with the Torrington. One other thing to do.... you can drill a small bleed hole in the direct drum to help keep the direct clutches from dragging. 3/32" is fine, but you need to know where to drill it safely to avoid issues. Use a torque wrench especially on the valve body as that's very critical in a TH400. If you get in there and need help just let me know!

Oh, one other trick. If you don't want to buy the tool to align pump halves there's a very easy no-cost way to do it. When you go to assemble your pump, just make sure that you've not yet installed the outer rubber oring on the pump, and then take your pump and sit it down into the trans case (empty case!) upside down. That way the case works as an alignment sleeve for the two halves of the front pump, and you can torque the pump bolts, then remove it from the case. I also like to use a cutoff bolt (take an old 2" long 5/16" bolt, cut off the head, and use a hacksaw to put a screwdriver slot in it...) as a dowel pin to hold the pump still while doing this, and then use the same dowel to locate the pump gasket later on when I get ready to drop the pump in for final assembly. Actually this works with many other trannies besides the TH400's. I have a few of these homemade alignment dowels around, and they're handy too for installing the valve body and it's gaskets.