TH400 rebuild: Direct drum

This video covers the Direct Drum of the TH400 transmission. It covers the common areas of wear and tear to look for on the drum. The video reveals the assembly procedure, along with some helpful tips. Also, learn how to make your own tools for the job!
Help this Channel Grow: • Help This KZbin Chan...
*****UPDATED TH400 Build Series*******
TH400 Teardown: • TH400 Rebuild Series -...
TH400 Inspection: • TH400 Rebuild Series -...
TH400 Building Clutch Drums: • TH400 Build Series - B...
TH400 Building Clutch Drums (Continued): • TH400 Build Series - B...
TH400 Bushings: • TH400 Build Series - B...
TH400 Prepping Case for Assembly: • TH400 Build Series - P...
TH400 Planetary Gear Set - Assembly & Installation: • TH400 Build Series - P...
TH400 Intermediate Clutch, Band, Direct & Forward Drums: • TH400 Build Series - I...
TH400 Pump + Front End-Play: • TH400 Build Series - P...
TH400 Valve-Body + Servos: • TH400 Build Series - V...
TH400 Filter & Modulator: Coming Soon!
TH400 Governor & Speedo: Coming Soon!
TH400 Different Cases (Chevy vs BPO): Coming Soon!
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Links provided are affiliated links with the associated websites. While there is no extra cost to the purchaser, a small portion of the sale goes to support this KZbin channel.

[@SouthpawAutoworks]

Thank you for being here! If it feels right to you, help me spread the word about this channel… 1 Handed Transmission Rebuilder (60 sec): kzbin.info/www/bejne/kIKrpaWMe7p7ms0

[@REPOOCNITSUJ]

Awesome video!! There are so many transmission videos where it ONLY SHOWS DISASSEMBLY!!! Thanks a million for showing in detail how to assemble, and having great camera work!!

[@SouthpawAutoworks]

Your positive feedback is very appreciated. I would love to circle back and redo these TH400 videos...as the video production has come a long way. Thank you for taking the time to drop me a line! PS - If it feels right to you, please help me spread the word about this channel. Here's an easy way to share... 1 Handed Transmission Rebuilder: (60-Sec Preview) kzbin.info/www/bejne/r2S5mquXlKqWZ6c How the 4L60E valve-body works: (60-Second Preview) kzbin.info/www/bejne/nIizhJSCmsaCjqs

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@nickkiofetzis5667]

this guy is truly the best teacher i have ever come across

[@SouthpawAutoworks]

Your support is appreciated. Thanks for dropping me a line.

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@nv1493]

You've got knack for clear explanations.

[@SouthpawAutoworks]

Glad it was easy to understand. Your feedback is appreciated.

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@johnnyb7825]

I have watched so many th400 video's and non of them is as clear in speech and view as your presentations! I would like to see a complete build on the th400! Along with some modifications, Like a shift kit And a tranny brake! Very nice details in your video's.

[@SouthpawAutoworks]

Thanks for the positive feedback. I would love to do a complete series on the TH400...and even update this old video. A shift kit and trans brake would make for some great content, for sure. I have been on the lookout for TH400 core. Not sure if you've subscribed, and hit the notification bell...but I just posted a video on how the planetary gearset works. While the TH400 gearset is not featured in the video, the basic principles apply to all units. The video features the gearset out of a 4L60E, the C-6, and partial stuff from A-518, A604/41TE, AOD/E/4R70W, and the E4OD/4R100. Planetary Gearset (Basics): kzbin.info/www/bejne/h5u3YXaLfJxmj68 Thanks for dropping me a line! You are appreciated.

[@SouthpawAutoworks]

You asked for a complete build video series... More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@SSRsGarage]

Dude some of the absolute best instructions on these transmission rebuilds !!

[@SouthpawAutoworks]

The positive feedback is greatly appreciated.

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@hackjobgarage9289]

I really like how thorough and straight forward your videos are. I am trying to get myself familiar with my TH400 and ran across your videos. Great job man, I just wish you had more on the TH400!

[@SouthpawAutoworks]

I'd love to redo all of those TH400 videos...and of course complete that series. In time, that will will happen. If you're interested in learning more about automatic transmissions, I'm diving deep into the 4L60E. A lot of the principles are transferrable across all automatic transmissions. Armed with the knowledge that is being shared, you will not only be able to make "informed" rebuilding decisions (parts & techniques), but you'll also have a much better chance of accurately diagnosing your own transmission problems. We're going a lot deeper than a simple clutch and band application chart. Latest 4L60E Video: kzbin.info/www/bejne/hoqUpaWQmrGkiq8 The video production values of the new videos are night and day when compared to these early TH400 videos. Plus, animations are now being used to enhance the learning experience. The viewer experience is at the heart of everything I do (video planning, filming, editing, etc). It's all about you guys... I appreciate your support. Thanks for dropping me a line!

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@tommysadventures]

Thank you you did a complete direct drum video. Many just toss it together and miss important steps. You however seemed to have touch on every step :-)

[@SouthpawAutoworks]

It's my goal to make it easy to follow along, and of course be thorough. Thank you for your comment Tommy Boy.

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@CORVAIRWILD]

I only help my former mechanic rebuild 1 transmission every few years, but it's still informative to watch your video, you're right to the point and direct and clear. Great video. I'll be rebuilding a 2001 4 4L80E shortly. It shifts perfectly but has 260,000 miles, and I brought the truck for heavy towing, so we'll see what's inside and we'll see how it works once it's rebuilt. I'll be posting on KZbin under the name corvairwild

[@SouthpawAutoworks]

If you don't use it, you lose it. I'm glad to hear that you're staying involved. I'm subscribing to your channel. I look forward to seeing your video. Thank you for your comment CORVAIRWILD.

[@CORVAIRWILD]

Nice to have you on board... The 4L80 never got dropped, maybe springtime... Lots on my plate...

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@foghornleghorn8536]

Thank you for all the effort you put in to making this video.

[@SouthpawAutoworks]

Foghorn Leghorn thanks for the comment. Hope it served you well.

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@TheBDD1970]

Very well done. You are a very good presenter/instructor.

[@SouthpawAutoworks]

Thank you for the comment.

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@kevincrowley5064]

Nice set of videos. Thanks for taking the time to create & post them.

[@SouthpawAutoworks]

You're welcome. Thank you for the comment Kevin CROWLEY.

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@bobbrawley9439]

Dat was one heck of viideo. Audio and lighting very good. yep, uh hum. A supper detailed demo and explanation . Tight editing is always appreciated. Oh yea. And color marking the tangs and ends are top notch presentation

[@SouthpawAutoworks]

Dude, I really appreciate your feedback/comment. More videos are being created right now. I'm now using pro-grade video equipment, to deliver a better video for you guys. Hope to see you commenting in future videos, Bob.

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@robertmedina3982]

Awesome video very insightful.

[@SouthpawAutoworks]

Thanks for the positive feedback.

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@testadds1105]

Thank you for your advices.

[@SouthpawAutoworks]

You're welcome.

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@skrattedieratte]

Awesome video and great advice. Sub'ed. As I am also currently rebuilding a TH400, it is really helpful to see videos like this! Cheers!

[@SouthpawAutoworks]

Glad it's helpful!

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@BrandonRosenstrauch]

Dude, you’re the man!

[@SouthpawAutoworks]

The guy(engineer) that designed this trans is the man. Thanks for the positive comment, man!

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@samualwhittemore228]

Subscribed! Very good!,

[@SouthpawAutoworks]

Thanks. Glad you enjoyed.

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@geojor]

very detailed video...

[@SouthpawAutoworks]

Thank you for the comment pei broker.

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@toddgreen8976]

bought a rebuild kit from Portland trans their kit came with a cd looking piece of plastic for those lip seals pretty slick enjoy your vids great job

[@SouthpawAutoworks]

Todd Green A green disc came in mine. I didn't notice it until the video was already created. *sigh*

[@ekaymoichubedi8876]

Where can i get a completly assembled direct clutch drum for my Th400 ex military 1985 chevy, i have the pressure plate damaged due to wrong installation of the torque converter.

[@SouthpawAutoworks]

I'm not sure. Perhaps Transtar Industries, who sells parts, offers that. You might try Natpro as well. How is the pressure plate damaged? Burned-up?

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@vrg69]

Awesome info

[@SouthpawAutoworks]

Glad it was helpful. Thanks for taking the time to drop me a line! PS - If it feels right to you, please help me spread the word about this channel. Here's some easy ways to share... 1 Handed Transmission Rebuilder: (60-Sec Preview) kzbin.info/www/bejne/r2S5mquXlKqWZ6c How the 4L60E valve-body works: (60-Second Preview) kzbin.info/www/bejne/nIizhJSCmsaCjqs

[@vrg69]

@@SouthpawAutoworks be glad to help have you got any complete th400 builds

[@SouthpawAutoworks]

Unfortunately, I do not... Started creating the TH400 video series over 7 yrs ago. Life happened...and that video series had to get sidelined. Since returning to the channel, I've been all about the 4L60E. If you take a look at some of the latest 4L60E videos, you'll notice that the videos have come a long ways, when compared to the TH400 videos. I intend to stick around for the long haul. At some point, I will redo all of the TH400 vids, and do a complete series on it.

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@nairblab4061]

Thanks buddy.

[@SouthpawAutoworks]

You're welcome! Thank you for the comment nairb lab.

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@cockasorrus7475]

Robert thanks for the attention to sub assembly components! That makes a nice way to isolate when rebuilding! I am just in learning - observation mode at the current time! lol I did notice that the round plastic seal installer in the kit works extremely well & I actually rarely used my wire hoop one. I noticed you put ALL the springs on the apply piston then removed half. I know that is what I did as well at least I am quite certain. I was saying to myself as you installed all of them, shouldn't that only be half? Then you took half of them off! I am sure that half will allow it to function with less pressure and result in a smoother function. The tip on checking with air is always welcome! Great mention on the snap ring locations. You are a master trans. builder!

[@SouthpawAutoworks]

Yes, those round seal installers do work well. For whatever reason, I happen to like the wire hoop one better...Just a preference. I don't recall that part(about the piston return springs)....haven't watched this video in a long time. Gonna have to revisit it soon. Been lucky enough to be mentored by master trans rebuilders.

[@cockasorrus7475]

@@SouthpawAutoworks you sure did and now you’re mentoring!

[@SouthpawAutoworks]

Hey James, More videos are on the way. Thought you might like this 60-Second video. TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@Mike-01234]

Nice video I read for street/strip you want the drum on the lose side.

[@SouthpawAutoworks]

You are correct. The clutch pack clearance is kept on the loose side, if high RPMs are anticipated(racing application). Doing so can prevent the clutches from being partially applied(when the clutch is not being used)...due to centrifugal forces on the oil behind the piston. What does centrifugal force have to do with premature clutch pack failure??? Here's what can happen to a clutch pack that's not being used, but it's still spinning with the rest of the drums inside the trans, while under racing conditions: When the drum is spun very fast, all of the remaining oil behind the piston is forced to the outside edge, of the inside of the drum. This, in essence, causes the oil level(if you will), to rise. Believe it or not, it will push the piston towards the clutch pack. However, it's only enough force to partially apply the clutch, but not firmly apply them. This causes the clutches to drag. This "dragging" of the clutches, creates friction, and a lot of heat...which causes the clutches to burn, prematurely. I hope that made sense. Thanks for the comment blastman8888

[@Mike-01234]

guitargube Someone told me 10 thousands per clutch in the direct so if you go 5 be 50 and 6 be 60 or so. Forward drum should be 10-20 thousands clearance. What do you think of those numbers? I plan on duel feeding the drum found lots of how to's on that.

[@SouthpawAutoworks]

I believe that figure is close enough for government work. I was told .008" per clutch, but your .010" per clutch is right there with what I was told, years ago. It's always nice when we have the specs handy. Makes life much easier. But sometimes we have to improvise. When the time is right, please share the results of your dual-feeding of the drum. Thanks.

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@cck1496]

Excellent video.... What is the issue if clutch packs lifts (raises) more than 50 thaus? Thanks for your excellent explanation.... Keep it up....

[@SouthpawAutoworks]

If a clutch pack has too much clearance, it can be tightened up by using different steel plates. The steels are considered "selective." Fancy way of saying that they come in different thicknesses. Multiple thicknesses: 0.060" 0.077" 0.090" Note: These are rough numbers (based off of reference material). In the real world, the thickness will vary slightly. For example, I measured some steels that I have handy, and I got these numbers; 0.063", 0.078", 0.093". Note: Be sure to measure each one of yours, as they do vary a little. This is helpful when doing basic math, when removing excess clearance. If all of your steels are 0.060": You can replace one of the 0.060" steels with a 0.077". This will remove 0.017" clearance from the clutch pack. You could do the same thing, but with a 0.090" steel. This removes 0.030" clearance from the clutch pack. Hope this helps. Thanks for the positive feedback.

[@cck1496]

@@SouthpawAutoworks Thanks for such a detailed explanation.... Keep us educating with your valuable expertise....

[@rodpalm6398]

Kinda sucks getting that last seal in isn't even the word, been there done that so many times. They have specialty tools for that outside seal which is a big cone shaped tapered round funnel so as to allow you to drop the sealing plate straight in but they are extremely expensive. I've used big C-clamps to get the springs pressed down enough to put in the snap ring. Getting the forward clutch to cog into the direct clutch is a real treat as well, best to use the forward clutch engagement cog to preset the direct clutches before hand. Appreciate the video.

[@SouthpawAutoworks]

Rod Palm That funnel cone set that you speak of is the ticket. Set the pistons in the cone, then freeze them with the special spray. That tool is awesome!!! Such a time saver. Installing the forward clutch drum into the direct clutches is a pain. I've seen a tool made for this: Take the forward clutch hub, that you mentioned, and weld a handle to it. It requires having an extra hub handy, but it works great!! A video is in the works...

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@peterbuilttough3406]

Discard wave steel in Performance trans

[@SouthpawAutoworks]

There ya go.

[@peterbuilttough3406]

@@SouthpawAutoworks good video brother

[@SouthpawAutoworks]

Thanks for the comments, man. Appreciate you.

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@Petejv89]

Can you use this same piston from this style drum on the smooth race style drum as well?

[@SouthpawAutoworks]

I would imagine so, but I'm not positive. Unfortunately, I don't have both designs (roller clutch VS sprag) handy, to do a quick comparison.

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@inscoredbz]

What's your opinion on wave plates in performance transmissions?

[@SouthpawAutoworks]

A guy can remove the wave plate from this direct drum. However, it will make for a harsh engagement into reverse...especially if the trans is shifted from drive to reverse. If the car is gonna spend time on the street, it's probably best to use the wave plates.

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@TheEinart]

Nice video, i just installed New seals on New piston for Direct drum, but i use some Automatic transmission oil for the th400 to lube the piston and seals, instead of grease, will that be ok too? i need a New clutchpack with steels too, should i go for 050 inch clearens too? my New piston is more slim so i can use more clutches and steels than my last piston, it was only 4 clutches and it shows around 60-70inch to the end,,i dont remember.

[@SouthpawAutoworks]

I'm sorry for the delayed response. Somehow, I missed your comment. The transmission oil will be fine for the assembly. Just so you know, you don't need special assembly lube(Assembly Goo, and the like). I have the high-tack Assembly Goo(green stuff), for holding things in place during assembly. However, for everything else, including lubricating piston seals, I just use good old fashioned Vaseline. Let me double-check on that clearance, and get back to you...soon.

[@SouthpawAutoworks]

Yup, 0.050" should do the trick.

[@TheEinart]

Thanks np, i just installed my new clutchpack with new steals from redeagle on my "lowprofile" piston, all the 7 clutches fits great in it..and my dial indicator (shows in mm) shows about 4.50-4.70mm (45-47 on dial indicator)..im not sure what it is in iches, but in the paper it follows it should be between 3.07-6.00mm (30-60) so im think im safe.

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@bobspittle3201]

Is it advisable to leave the center seal out of the direct??

[@SouthpawAutoworks]

Great question. It depends... What you are doing with the transmission? Is it going in a vehicle that will be grocery-getter, a track rocket, or off-road crawler? If it's doing some combination thereof, then where will it spend most of its time? Or what is most important to you...all out performance, or comfortable driving? All things to take into consideration. I've always installed all of the seals on this particular drum. I understand why some builders will leave it out (racing purposes). Under normal conditions (daily-driver), all of the seals will be installed. The direct drum clutch is activated when the trans is in Reverse, and when it's in 3rd gear. When the trans is in Reverse, oil is sent to both sections of the direct drum piston. Doing this increases the pressure that the piston applies to the clutch pack...basically enabling the clutch pack to withstand more abuse before it starts slipping. However, when the trans is in 3rd gear, oil is only sent to one section of the piston, resulting in less piston pressure. It's done this way by design. When the trans has shifted to 3rd gear, the vehicle is already in motion. The engineers figured that the clutch doesn't need the extra holding power since the car/truck is already rolling at a higher speed, when the 2-3 shift occurs. If that trans is gonna get pushed hard, in all forward gears, then increasing the clutch holding power of 3rd gear (by removing the inner seal) may be what is needed. Another consideration is shift quality. Removing that inner seal, it may result in a harsher 2-3 shift (I'm sure this can be addressed, or at least minimized, with the orifice in the separator plate, the accumulator, etc). If the trans is used on the track, then a harsh upshift is not a concern. But, if it's a daily driver, a harsh 2-3 upshift may become bothersome. The center support has 3 feed holes; Two (2) for the direct drum piston (3rd gear uses one feed hole, and reverse uses both), and one (1) for the intermediate one-way clutch (lube oil). I believe that this center support needs to modified (a hole plugged) so 3rd gear oil isn't exhausted through the reverse circuit. Remember, the direct drum clutch is used for both 3rd gear and reverse. If oil is allowed to exhaust, when it's not supposed to, it's like having a huge oil leak in the circuit. Big leaks result in smoked clutches. Hope these questions, and info, help you to make an informed decision regarding the piston seal.

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@ronniebuicks5569]

what year th400 would you recommend?

[@SouthpawAutoworks]

I do not have a recommendation on any particular year. The rebuilding procedure/techniques are what's important. ;)

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s

[@bobbrawley9439]

Dat was one heck of viideo. Audio and lighting very good. yep, uh hum. A supper detailed demo and explanation . Tight editing is always appreciated. Oh yea. And color marking the tangs and ends are top notch presentation

[@SouthpawAutoworks]

Dude, thank you for the comment. Much appreciated.

[@SouthpawAutoworks]

More videos on the way! TH400 Rebuild Series - Coming Soon kzbin.info/www/bejne/p2HIlJyOip2Me6s