Race TH400: Drums

Forward and Direct Drum info.

[@erikschnell6225]

love all your videos thank you for sharing your knowledge with us

[@krazobuildz7567]

I’m getting ready to do my 400 I like ur channel it’s all about 400s thanks bro

[@Roscotech]

I could use a little clarification on plugging the center support as the sort of last step in completing the dual feed mod on the direct drum. I have left the center seal out of both drums and the second sealing ring from the center support. I would just like a visual on the plugging of the center support so that reverse and hi gear work properly.

[@mountainsgarage]

Standing at the rear of the transmission with the valve body up I drive a 3/8” plug in the right hand hole next to the center support bolt.
You could also weld up the hole in the separator plate.
Good pictures and info on the Crankshaft Coalition TH400 website.

[@mountainsgarage]

www.crankshaftcoalition.com/wiki/File:T-400_feed_holes03.jpg

[@cfmechanic]

Nice to see the parts my trans guy told me about. When they built my 400 they also installed the 4l80 drum. Cool to see the differenes

[@gneric85]

I have been building since the 80s but I still enjoy watching what others do. :-)

[@davidshoemaker4195]

Will be an subscriber because of who u is

[@tomkeogh9471]

those borg warner clutches with the parallel grooves i found the friction material chips off in chunks. i prefer the borg warner smooth never had a problem with those.
in my performance builds ive been using the raybestos waffle graphitic in the direct with good results also

[@mountainsgarage]

Good info! I am always trying something. When things are right they are all good!

[@MrLangleylad]

Thanks Shawn

[@clarencemack4382]

Can I install my stock case bushing through the rear instead of the front ?

[@jonathanbeauchesne3657]

Question check balls in the four drum what happens if there's no check ball I just disassembled my trans and no check ball what does or don't happen like your videos

[@jakestree1892]

Is there a difference between the brands of the 34 element sprags as to quality of the parts?

[@mountainsgarage]

I prefer the Borg Warners, but have used some cheaper ones with no issues.

[@vrg69]

The forward drum needs to have a check ball or the piston needs a check ball correct

[@mountainsgarage]

Yes it does.

[@kentklassen8397]

Hey Shawn love your videos .. are these mods specific just for trans break th400's Like drilling and 1/16 bleed hole to dual feed I'm building a non trans break th400 I'd like to up grade a few things..
Thank you

[@mountainsgarage]

No the bleed hole is good to prevent centrifugal apply while spinning high rpm, dual feeding is a standard mod for all TH400’s.
Check out the Crankshaft Coalition’s TH400 webpage, full of good street/strip mods.

[@DynoPro]

Thanks for all the great info, truly priceless!! I have a direct drum with no check ball. Do I need to drill just one 1/16 hole or two since no check ball? Thanks.

[@mountainsgarage]

Probably best with the bleed hole and a checkball piston.

[@inscoredbz]

Exactly what are the check balls for? Do they block fluid from escaping the drum when pressure is applied, or doo the release fluid when pressure is let off?

[@inscoredbz]

Hi Shawn, I have learned a lot from your videos. Is the dual feeding the forward drum a must? I'm building a street car and I'm going full manual valve body, keeping the front band and plan on running fixed line pressure, so I'm thinking of leaving the forward drum seal in place and keeping the wave plates in both the forward and intermediate clutch packs. I have had them slam into 1st gear in the past (putting it into 1st gear was very harsh) and trying to take a little shock off the intermediate sprag and race. I'm drilling the 1-2 hole in the plate to .125", using 12 intermediate piston springs (from a 4l80e) and leaving the wave out of the direct drum and drilling it to .150", and blocking the bore on the 3rd accumulator in the valve body and removing the spring (as you've shown to do both). I'm using a 4L80e direct with a 34 element sprag. I can either use the factory pressure regulator spring and 1 horseshoe or a yellow transgo pressure regulator spring that transgo says is 25psi over stock. Do you see anything wrong with this setup, or should I change something? I appreciate any advice you have to offer.

[@mountainsgarage]

Hi!
Sounds like a good plan. Putting the center seal in the Forward will soften the engagement some.

[@inscoredbz]

@@mountainsgarage thanks. Which pressure regulator spring should I use? Stock with one horseshoe, or the yellow transgo spring that comes in the sk400 kit? I bought the kit just for a new separator plate and the spring came with it. Transgo said it's 25psi over stock, so I would figure it's around 200psi.

[@mountainsgarage]

@@inscoredbz Full Manual might as well go with the Transgo.

[@bobspittle3201]

If you leave the center seal out of the direct wouldn't 3rd and reverse apply at the same time??

[@mountainsgarage]

You have to plug the hole in the case or on the separator plate, and leave the second seal off of the center support to complete the direct drum dual feed mod.

[@williemccary2462]

I thought u remove center seal from da direct drum for daul feed

[@mountainsgarage]

Yes center direct drum seal, second seal back on the center support, and block the feed hole either in the case or separator plate .
With an aftermarket valve body sometimes part of the process is already done.

[@chrisrichardson5841]

are 4l80 and turbo 400 lip seal tools the same?

[@mountainsgarage]

Going by memory the tools for intermediate inner , both directs, and the inner forward all work fine. The forward outer and fourth clutch need 4L80E specific tools.

[@chrisrichardson5841]

@@mountainsgarage thank you about to dive into a turbo 400 build and looking to see if i can afford the fancy tools

[@leeanamercado8836]

What’s the part number of that piston install tool

[@TimothyGambino9085]

I have a early 70’s turbo 400 I wanna put a 36 element sprag in it.
I don’t understand what you mean by a needing a round drum? All the drums look round to me?
Help

[@bobspittle3201]

The round he's refering to is where the sprag rides. Some of them have the round race surface and some have a ramp (hump) style race surface. The sprags a completely different.

[@TheAkstewie]

Do you have a websight where I can send in my th400?

[@davidshoemaker4195]

Hey Shawn how do hop an olds???

[@mountainsgarage]

Dave!
I just mentioned you in yesterday’s video!
I have fond memories of a yellow Olds!

[@funfun8095]

👍

[@vrg69]

On the forward drum you don't drill a 1/16 hole correct

[@brock007football]

I would like to know this also?

[@vrg69]

@@brock007football you do not

[@terrywilson581]

😊😊😊😊😊😊😊😊😊😊

[@williemccary2462]

Hey how much u charge to da a racing 400 build

[@mountainsgarage]

When I supply everything including the core they range from $2-3000.

[@williemccary2462]

I have da trans

[@stuartbuckley8720]

@@mountainsgarage where do we send it to, can I drop it off? I live in Michigan.