Rebuilt Th400??

[new]

Hi

I need yours advices and information to rebuilt my th400 transmission.
I have sbc street car (about 500 hp, maybe some day put juice 150 – 200 hp). Weight about 3300 lbs, rear end 3.9:1 and converter stall 3000. Th400 with original cast iron valve body (modification to manual valve body). Original parts.

I have been pick up information by Ron Sessions book and internet. This is my checklist. Is it any brain, let me know:

I will put new bushings and bearings.
Oil pump gears and body clearence 0.001-0.0035 in
Total end play (oil pump and forward clutch drum) 0.003 -0.025 in.

Forward drum 4-5 clutches, direct drum 5-6 clutches and intermediate 4 clutches.
Forward clutch stack clearence 0.035 – 0.045 in (not wavet plate?)
Direct clutch 0.04 – 0.06 in (not wavet plate?)
Intermediate 0.04 – 0.05 in (not wavet plate?)
RedEagle or someone else goot clucthes.

New wider front band
Aluminum accumulator piston

I have 4L80E direct drum with 34 element sprag.

Question about direct– and forward clutch piston. There are cast aluminum and stamped-steel. Both piston are the same size. Can i changes these together? If i must to get some more space to clutches. Can i take off some material at stamped-steel piston, so i can put example 6 disk in the direct drum? Or can i take some material off at backing steel plate or is it nothing matter which one?

I will buy 4 intermediate clutches pack kit (plates, clutches and ring).

Center-support spacer ring (0.04 in). Spacer open end toward to band pin. Rear end-play 0.007 – 0.019 in.

Deep oil pan and good oil cooler

Let me know you opinion.

Thanks

[Hutch]

Here's a revision .

Forward 5 dir 5 int 3 Use a wave if you want a somewhat cushioned apply with a 3000+ stall converter you likely won't care about the forward engagement so forget the wave's.
Clearances sound ok.

Wide band, don't need unless you plan to do a lot of downshifting.
Alum pistons , good idea.
Use the right aluminum pistons to the drum its used in with or without checkball.
Steel pistons are garbage but if its all you have then you may have to use them. I will never use them.
Center support spacer ring? Its either used because you have a center support that requires it or you don't but its not an addition .
Rear endplay specs are ok but if its tight I suggest you use a torrington bearing there and ditch the washer.
Also get yourself some teflon sealing rings and give it a try.

Good luck with your rebuild , Hutch

[Gregaust]

Just be careful if mixing pistons. The guys on here helped me a little while ago. I was left with a piston and drum combo with no checkball or bleed . On Hutches advice drilled the bleed hole at .040" and it is all running sweet .

http://www.yellowbullet.com/forum/showthread.php?t=64654

As mentioned go with the T350 bearing at the back ( i used the bearing and a .010" shim) and make sure to dual feed the direct . The one i built is in a 383 small block street car making 420 RWHP.

[chris718]

Add a final drive sun gear bearing from an axode to the forward clutch hub and you now have a rollerized clutch hub with no machinig.Itll drop front end clearance all the way down as well so have an A type front pump washer on hand.The new 4l80e graphite rings seal better than the cast iron,and solid teflon as well.There are 2 rear end plays.One is the output shaft rear carrier w/ washer ,front carrier and center support with rear washer.Adjust this first ,then install the rear ring gear to output bearing with rear ring gear and int. shaft ,the rear sun gear bearing ,the sun gear ,the sun gear to support bearing and pull up on the int shaft.Now adjust this with shims under the rear ring gear bearing.Never let int shaft end play be greater than the output clearance without the parts I mentioned to leave out on the first check.Late 4l80e int cushion plate does help the sprag from getting whacked as well but you need the aluminum piston.

[new]

Thanks a lot Hutch/Gregaus/Chris

What about direct drum clutch (4L80E), it seem to be aluminum piston 0.61 inch thick. Can i put 6 clutch in the drum? What about clutches and steel plates thick?? Must i buy 4L80E clutches which are thinner than th400 clutches?

On the direct drum is one checkball and one small hole side the drum. Piston have not any checkball. Gregaust you said must be dual feed the direct. What does it mean? Sorry i don't unterstand english so well.

Th350 pump bearing can use on TH400 at the back. Have to modificaton the case or will i take a way original back washer and put bearing in it?

Chris i am interested in Axode bearing to the forward clutch hub and also snap ring stabilizer. Can you give me your e-mail address?

Ps. i did not open th400 yet, but i bought 4L80E direct drum and some other parts.

Thanks