TH400 Rebuild: gear set, center support & intermediate clutches

start on reassembly of transmission

[@peterbuilttough3406]

For any doing a trans build, I've found this is one of the best step by step th400 builds on youtube. No skipping around shows how every part is put together well done!

[@fastelbow]

very good video. I am building a street th 400 for a 1972 Chevrolet pick up and so far on youtube this is the best video . Thank you.

[@Dragracetherapy]

Thank you! Wish you the best on the truck build!

[@billdavis3128]

Great video very informative I am going to build a th400 to install behind a 535 RB. Dodge eng going in to a 1950 Dodge truck.this will be my first attempt at this build but after watching your video I feel confident. Thank you.

[@chadpipkin840]

Great video just about to try my first build on a th 400 with reverse valve body

[@BigFun4Life]

Great video man,thanks for sharing…

[@Dragracetherapy]

Thank you for watching!

[@jimwhalen6769]

Great video. One note you might want to consider. The case snap rings, the openings should be at the 3 o'clock position when. In your case you are using the case saver in place of the band, that only supports the top snap ring and leaves the beveled snap ring vulnerable. Grate job and you had more information that some other videos I have watched. Thanks! Oh and I also love your taste in music!

[@Dragracetherapy]

Thank you for the info!

[@kennethhudson8013]

You know what you are doing

[@6bangerwander260]

Amazing taste of music my dude

[@AbodyTomsgarage]

Your getting there bub keep it up 👍🏻👍🏻

[@papergatorzfedducca7998]

What year and what car did this transmission come out of? I’m asking because in my area I see cores for sale all day and I want to buy a few and build them. TH400 Chevy the ones to get? What do I look when looking to buying one?

[@quadrigacars2776]

Where is part 2 ? Great video

[@Dragracetherapy]

Thank you so much for the view and comment!! Unfortunately, At some point that video went missing. I do have some content still, that I might be able to put something together, but I can't promise anything.

[@quadrigacars2776]

@@Dragracetherapy no worries mate - I’m building up a th400 and suspect the last guy before didn’t do a great job - I’ve some questions for you Intermediate I can’t get lower than .83 thou - 3 stock frictions 3 stock .100 steel’s and .432 top - no wavy plate fitted but found one in my store - but doesn’t help - so I’m thinking fit wavy then take .40 off of top steel??? Finally is there any roller bearing between direct and forward drum? In your video ( no part 2 ) I couldn’t see one ? I don’t have anything in the tranny- wondering if the last guy left it out

[@quadrigacars2776]

@@Dragracetherapy it’s hard to make it out in the book - so many revisions on the case years as they went on - so I need to sort intermediate and unsure of any bearing between direct and forward?

[@Dragracetherapy]

@@quadrigacars2776 intermediate clutch clearance can be tricky. In most cases ppl throw them in and let it ride. A rule of thumb is roughly .010 of clearance per clutch. If you want to add some strength to the intermediate clutch may I suggest the clutch kit from a 4L80e... This is a 4 clutch pack. Assuming you are using a stock forward clutch hub, there should be a thrust washer between the direct drum and the forward clutch hub/drum. If you're using the sonax HD hub then they machine the hub and use a Torrington bearing that they supply with the HD clutch hub.

[@quadrigacars2776]

@@Dragracetherapy thanks so much - so the copper thrust was left out by previous builder 🤦‍♀️ So that would go onto the direct clutch drum so the forward drum can sit down onto it - On the intermediate I will add a steel and machine 40 thou off giving 35 thou clearance Thanks for your reply pal 👍

[@tomcruden]

where is part 2

[@quadrigacars2776]

Hi - thanks for part 1 - where is 2 ?

[@garrettcarpenter3319]

I have a home made full manual valvebody and lost first gear pulled valvebody and noticed some tabs in the pan

[@Dragracetherapy]

Time to tear it down 👍

[@ijteague]

How crucial is the lube holes lining up on the sun gear and shaft? Seems the canal around the shaft would allow fluid to find the hole regardless. Is it same for a regular build as a race build?

[@Dragracetherapy]

Some of them have alignment splines cut into the gear, otherwise, it's a good practice just to align them. You would want to make sure the rear gear sets are getting plenty of lubrication regardless of whether it's a stock or performance build.

[@HilBilySasquatch]

Good video.. but I am stuck. At 28:28 there seems to be a snap ring in place before you install the center support is this right??? You never showed this part...

[@Dragracetherapy]

Yes, it's called a fretting snap ring. GM started using them around early-mid 70s to help with case wear under the center support. Some had them some didn't. Center supports were different too. Center support should fit snug when the upper snap ring is in

[@bigblock406ta]

Awsom. But I thought you said this was your first one. Lol

[@Dragracetherapy]

God's honest truth, it was lol

[@bigblock406ta]

@@Dragracetherapy what was your best ET so far have you been back to the track

[@Dragracetherapy]

@@bigblock406ta first time out, prior to the trans rebuild and no transbrake... Car went 11.40 @ 125mph.... 1.8s 60'.... 10psi and 14* timing... Just a shakedown pass...oh and it was mid 90s and high humidity lol... Haven't made it back.... Hope to this year

[@keysautorepair6038]

Aren't you supposed to use Teflon rings with a transbrake.

[@Dragracetherapy]

It's recommend to do so. Keeps down on excessive drum ware due to higher line pressure

[@gmtech9884]

Hello I need some help wondering if you can help me out I have the same trans break . Why did you remove the second seal - on the center support..How did your transmission work out?

[@Dragracetherapy]

Removing the second seal on the center support is done as part of "dual feeding" of the direct clutches... Just As you also leave the inner lip seal off the direct clutch piston... This allows more fluid volume to press against the back side of the direct drum piston allowing more clamping force on the clutches... The last part of this modification would be blocking the reverse port on the trans case (next to the center support bolt) but the separator plate that comes with the Transbrake already does this for you as there is no holes for the port in the transbrake plate. Line up the old separator plate and the new one and you will see what i mean. As for my transmission, it has been working great! I'm very happy with the way it turned out!

[@notyou6950]

Just a tip: cut that background noise off before you start filming. I don't care what noise you like. It's distracting from what you are saying. What's more important, you or Alanis?

[@Dragracetherapy]

Agreed. Honestly this was was one of my first videos and I was still learning when it comes to cameras, audio and editing. But thank you for the pro tip

[@clarencerobertson2372]

do have the site for the center support piston upgrade

[@Dragracetherapy]

I did a search for th400 intermediate clucth piston on ebay and found a guy on there selling them.

[@jordanrussell345]

What are you using to stand this trans vertical?

[@Dragracetherapy]

Engine stand and a homemade jig

[@daviddavis9411]

Volume to low

[@Dragracetherapy]

Thank you for the feedback! We will try to address this in future videos.

[@kennethhoisington566]

Pop up pop pop ó0o

[@TimothyGambino9085]

Was gonna subscribe , but it’s the worst audio video I’ve heard in a while . Ridiculous