As stated, I'm building my first TH400. I've got the Cliff Ruggles manual and the ATSG manual. I've also read a bunch online. So here is what I have found out so far about my particular transmission.

I paid $100 for it originally, was told it came from a truck, appears to be a 1979 model trans. It doesn't have an output shaft housing on it, so I'll need one of those. Was also told that it didn't have reverse. Upon tear down I noticed some sort of material through out the trans and it appears that it came from the reverse band. This trans has the rough finish drum and it appears that a smooth reverse band was installed at some point and I assume that's probably why the trans lost reverse? The band was loosing a bunch of its friction material. All of the clutch packs looks pretty good and nothing looks burnt there. The low roller clutch fell apart when I removed it, a bunch of the rollers fell out, that'll be replaced. I measured all of the bushings and adjacent surfaces that ride in the bushings. Seems I'll be replacing those, here is what I found for clearances:

Main shaft to sun gear shaft clearances = .0062" - .0075"
Pump stator shaft bushings (front and rear) = .0073" - .0151"
Main shaft ring gear to output shaft bushing = .0131"
Reaction carrier bushing to center support = .0068"
Center support bushing to sun gear shaft outer = .003"
Case bushing to output shaft = .0043"

Output carrier pinion = .022"
Reaction carrier pinion = .015"

I plan on following info found in this forum especially cameronvic's build thread and from http://www.crankshaftcoalition.com/wiki/TH400
http://www.ckperformance.com/Tech-Bl...gCategoryID/62

The trans will be going behind your run of the mill 6.0 LS turbo engine. If I had to guess it will make between 600-800whp on E85. I do not plan on putting a trans brake on it right now and plan on just modifying the stock VB.

I have some questions about a few of these parts.

Aluminum apply pistons, are these the correct parts?
https://www.ebay.com/itm/332583972931
https://www.ebay.com/itm/152788725936

4L80E direct drum and sprag

Aluminum VB accumulator piston

Torrington rear case bearing
https://www.ebay.com/itm/141923630914

Also, I'm unsure if I need a different output shaft or if the one that came in my trans will work. I think I have to change that and get the correct housing.

Other than normal wear and tear parts that would be changed in a rebuild such as case seals and lip seals, frictions and steels, bushings, etc is there anything else I should look into? Am I going in the right direction or missing anything? I've looked at those master rebuild kits and they either have more than I'll need to replace or don't have everything I want, so it looks like I'll be sourcing the stuff individually.

 

For me,, I'm all about doing it once..

Doesn't matter if its a transmission , engine, whatever,, I put all new seals on anything that gets opened up, new gaskets, and I use Aviation sealers where applicable. I had to re-pull an engine once due to not replacing a 10 dollar seal.. Never again.. (Isuzu trooper death of a thousand cuts)

Sounds to me like you've mapped it out pretty well, Keep everything clean, use ATF on any seal and pre-soak the clutch packs/bands any friction part in ATF before assembly.

Gonna watch how it goes!

 

At one point in my life I was an aviation mechanic (USAF) so I'm all about doing it correct and not having to deal with taking it all back apart.

I just have some questions about the parts I listed that I'd like to install during this rebuild and if I'll need to be tracking down the correct output shaft and housing, which I think I will be. I've been reading a lot about these things for a couple weeks now and I get lost in some of the information I find sometimes.

 

I know how you feel, I'm in the middle of sorting how a 6L80 and 8L80 series work... I'm planning on a Ly+6l80 in my Jeep cause I want the gear splits and the highway performance. So I'm hoping to add telemetry to the trans so I can compare the tune to the solenoid behavior.

One of the tranny build threads on here has a really good blow by blow on some TH400 parts choices but my search fu is weak tonight.. I'm more of a off-road 4x4 guy so I havn't dug in to drag tranny strength tricks.. I've always just used a commercial truck/bus rebuild kit(s) and I have a buddy that used to be a line rebuilder so he knows the assembly tricks..

 

Can someone tell me if these are at least the upgrade to the steel pistons that were in the trans?

https://www.ebay.com/itm/332583972931
https://www.ebay.com/itm/152788725936

 

Yes, the aluminum pistons are what you want. Price seems insane though.

 

Know of anywhere I can get some at a better price?

 

I don't. But you can probably find a whole core for about what they are asking.

 

https://www.wittrans.com/parts

 

https://globaltransmissionparts.com/

 

3rd time in a few days I've seen that site pop up in a recommendation. I'll check them out.

 

Great place, I have one local so it's nice I can just stop in there.

 

So I just ordered the aluminum apply pistons and the 80e direct with sprag. So that's out of the way for now.

 

send me a list of hard parts you need, pay the freight no charge one time

 

how can you beat FREE!!!

 

lf free is not good, how much do you charge me to give you parts

 

Thanks for the generosity, but I think I have everything for it right now.

 

that's a 4x4 out put shaft