Re-sealing, maintaining the TH400....basic questions:

[COBALT]

OK. I've got the front-end rebuilt, the rear-end suspension goes back together this weekend, and it's now time to drop that tranny while the driveline is out, and reseal the transmission. I've got the "pre transmission work" jitters. I just want to make sure I don't do anything dumb, or put it back in the truck without doing something vital.

I've got the new seals, new pan gasket, filler plug kit, new filter and parts. I have a bushing kit on the way + an extra Th400 pump bushing in case for some damn reason it's not in the kit. I think I have all the tools I need. All the bases covered.

Questions...I know the front seal is leaking. That's a no-brainer. So is the pan gasket and filter. I know I need to inspect the torque converter for excessive wear, so the front pump bushing is what I'm really wondering about:

1. Will the state of the torque converter be an indicator of what's going on with the pump (I assume so)?

2. How do I know whether or not the bushing in the pump is bad and/or just needs replacing? Will the kneck on the converter show excessive wear?

Even if I don't find excessive wear I figure it's probably a good idea to just replace the bushing anyway, so I assume I need to take the pump apart, inspect the pump gears, and since I'm in there just replace the bushing as a matter of course (basically do everything short of pulling the front clutch drum and do a complete rebuild). So, do I:

3. Drive out and put the new one in with a std. bushing driver for that size?

4. What's the size of the bushing?

Anything else I should be putting on the checklist???

I'm pretty confident that I can handle just about anything. I've got another Th400 I'm actually going to do a rebuild on here pretty soon, so I have no fear! (at least not yet).

[Zkast]

You wont be able to get an accurate reading by looking at the convertor hub. Definatly look at it and make sure there is no scoring going on but you'll want to look down inside the pump housing and see what condition the bushing is in. IF the seal is leaking its a safe bet to go ahead and replace the bushing, more than likely this bushing is worn and causing the seal to leak.

Pulling the pump isn't really a major ordeal if you've had experience with transmissions. You have to take extreme care in installing the pump or you will shave/tear the teflon seals for the forward hub and the sealing oring on the outside of the pump. The pump is actually an assembly of 2 halves and 2 gears. Dont take the pump apart unless you have alignment tools ( aligning band).

I'd suggest (unless your comfortable doing it yourself) that you drain the transmission and convertor, take it to a transmission or automotive shop you trust and have them install the new bushing. They can also inspect the TC while its out.

[crazy longhorn]

if you have a spare bare case, you can also use it for an alignment tool when assembling the pump......turn the clean & loosely assembled pump upside down in a bare case, & use feeler guages between the OD of the pump & the case to center it, then tork the pump bolts. this works well on an overhaul, as you dont have to scrounge for an empty housing. Good luck.....crazy AL

[COBALT]

I've got an extra th400 I need to rebuild, but I know what Zkast is talking about. I'll just take this one step at a time.