Asked you about th400 oil pump whine few months back, you suggested to use a metal screen filter. I replaced the alto filter with wix 558890 allison metal screen filter. The whine is gone now! Thanks for your help and keep the good videos coming 👍

Built my th400 with the help of your vids. Couldnt be happier with it.

As always, outstanding information Mr Mountain and thank you kindly for the great advice and tips!!!

I used this video and a few of your others to build my first TH400. Its reverse manual VB, Tbrake, and the thing is an absolute animal!! Behind a turbo LS. Only been driving it a month and a half but the thing is doing great! Thank you so much for putting good, tried and true info out there.

Just got my trans installed in my 9 second camaro. I used your 1000 hp formula and the thing works beautifully. I used all coan parts and transbrake with a TCI 4500 stall tightened up for nitrous use. I was worried sick the trans wouldn’t work right and it works better than expected. I can’t thank you enough for the questions you answered and the time you took to get me through it. I’m confident enough now to do my own race 400s. This is an extreme confidant builder. Thanks again.

great video, lots of things to consider. thanks Shawn.

Just love your th400 vids have beening running one in a dragster for 20+years mostly stock but zipper it bad when we stepped the hp up to 1600 now building one a bit stronger so I love your channel parts are hard to find and dear here in OZ as we have to import most parts from the US Cheers from Downunder

I remember years ago an ol' timer saying that he machined the case for strength. I can't find anything to that effect online. I wish that I would have paid more attention to what he meant. Subbed to your channel. Very interesting. Thank you.

Can be more plain than that! I've learned a lot by watching your channel. Thank you!

I use the switch pitch turbo 400 correctly called the variable stator converter in the turbo 400. It is an electric activated stall converter and electric controlled shift. Not to be confused with the electric lock up converter. Two completely different animals. Easily carries my 600 hp big block Buick engine in the Binderbird.

Good video, excellent communication skills

Video is on point. Awesome man

You information is awesome mate. Thank you for your time and knowledge

Love your channel brother. Ty. Can you show how to file/flatten a case with a wet stone? What grit etc?

Thanks more thorough then most people on that build.

i worked for a transmission remanufacturer in the parts dept they wont miss 1 clutch or steel x 100,s over the years & a dumpster full of parts from the builders

By the sounds of it, your an epping guy.. great vid!

Been working my way through a ton of your videos for my first th400 build, I have a 4l80e I'm stripping parts out of. I'm swapping in the direct drum and forward hub. Is there anything else I should be swapping for any advantage seeing as I have all the parts available? Also putting in a tci full manual reverse valve body. And I just wanted to say I really appreciate all your videos the have been a ton of help!

Great video man

i been getting the 02xx 400r turbo for free it is good to 800 hp stock so far i have got 4 crate setups for free with the 450 hp 454 with the 02xx trans from 6,000 to 58,000 miles on them the trans come with the 8 bolt pump heavy clutches stage one shift kit with a few extra the engine come with steel crank heavy rods high flow heads 10.5 to 1 compression just needs to breath with a bigger carb and a good intake it come alive . i put one setup in my 68 pu and the trans works great not quit as good as my pro built 400 turbo which is good to 2000 hp but way better then any standard 400 turbo

Thank you for sharing your information.

Your videos are amazing! Can you recommend a quality rebuild kit?

Whit Sonnax 34762-10 case saver you should be able to run the front band.

Do you need a manual valve body for this ? Or can you just add a shift kit and shift manually? Also can I use the stock springs or should I upgrade to stiffer springs ?

It sounds like dual feeding the direct clutch wouldn’t help me much but I’ve heard you briefly mention dual feeding the forward clutch. Is there any other modifications needed other than leaving the seal out? And can that be done and run with a stock valve body? Also if you ever need any 2wd output shafts or tail housings i have a bunch of them. I’m always in the market for 4wd output shafts

Hello mountains, on a th400 street and strip 400 do you have any good advice on without a trans brake build ? Any do's and don't things thanks.

Love the video! I am not worried so much about hp level but what are your thoughts on making a th400 with auto shifting as aggressive as you can. I have seen the mild th400 videos. how about an aggressive th400 auto shifting street build. Thanks for all your hard work

Hey shawn, is there a particular complete "rebuild kit" that you can reccomend for a stock th400? I've heard alot that waffle style clutches and tan clutches are a good choice. Looking to buy something that takes the guess work out of piecing together what I need

holy hell, thank you so much for these videos

I don’t know if there’s much demand for it but I was wondering if you’d be willing to make a video on what to do for something that’s even more mild 500 hp and 600 foot pounds of torque auto shift? Thank you

I added you to the diy th400 fb page lol

I love my th400. I know its heavier than a th350 but it really makes my car feel alot faster. With the th350 I couldn't chirp the tires but with the th400 I can either drive like a grandpa or shred the tires on command. So far I have just been careful on the fwy I have 3.42 gear and it wilk not downshift at fwy speeds. People tell me I can do it but I broke 3 intermediate sprags so I am a bit overly cautious.

I have a th400 trans from a RV that was bolted to a 454 big block engine with 80k miles. What are some things I would you recommend doing to it or just rebuild it back to stock I'm bolting it to a 5.3 ls engine for the street no racing. Rebuild it with a new converter .

Hi Shawn you have the best videos on KZfaq but wanted to know what length the moduler block off plug has to be?

I have th400 500hp build and not a transmission guy, can you please tell me the tolerance for up and down play on output shaft.

How much do you charge to build a 1500 hp or so 400 trans

Whats the part number for that intermediate spirolok/snap ring for the case? Thanks

Great info, Can you put a link to these products so we can purchase them all from one place! Thank you, B

what snap rings did u use for the itermediate

I’m building a turbo 408 stroked Windsor I def will need one for my set up I’m a street car also how much does it cost to build one? Thanks !

Quick question buddy if you’re doing a 400 with a 400-3 Transco shift kit can I leave the inter seal in the direct drum out and including the second ring from the top on the center support

Hey what’s the part number for the intermediate spiral lock. The larger one you show next to the case saver is upside down and I don’t believe you mentioned it.

How much would you charge to build a 400 turbo to withstand 1000 horsepower?

I'm having a hard time locating some of these parts...Would you make a video giving part numbers on the parts you recommend?

shawn you mentioned that the forward hub is a good idea. how crucial is the upgrade is it vs a nicety? is it just towards this power level that it becomes a good choice? what happens with failure? i have all the tools i think ill need. -Trans case holder for engine stand -pucks of various sizes that can be used to press bearings -clutch depresser tool -big hose clamp for pump -dial indicator + base -sockets, snap ring pliers, picks and various hand tools -green assembly goo -3l80e astg book i also grabbed a supposedly still good th375 for a $150. if the steels/clutches/etc look fine ill reuse them. -used 9.25" truck output yoke and new tail housing -sfi housing -transgo hd intermediate snap ring -direct clutch drum + 34e sprag (assume 4l80e since it lists for both th400 + 4l80e) -case saver -roller bearing + shims just need to pick a transbrake, both atd and jakes are on backorder. probably go for a jegs/summit kit thoughts? missing anything? thanks for sharing! youre an inspiration!

Awesome!!!!

I have a question for you. I have a turbo 400 in my car runs 980s at 137. The car works great except for when we go to push it out of the trailer. It does not want to backup. Worth of shit goes forward. Fine pushing it. I just had it serviced new clutches and stuff and it still won't push backwards worth of crap pull the driveline out. The car pushes backwards like nothing. Have any ideas?

Can you explain how important it is to start a burnout in 2nd. I never got that. I think I hurt one shifting 1st to 2nd at 6000 with sticky tires. Not spinning. 600 HP. If it hurts these trannys that easy isn't a beefed up T350 better?

Hey. Just ran across your videos while searching for th400 rebuild. I build a bunch of rock crawlers with LS motors and 400 transmissions. Decided to start rebuilding them myself. In the past I’ve had them apart to swap 2wd to 4wd output shafts but never been into the drums or pistons. All the videos I see are usually for street cars but I hardly ever use 3rd gear. Mostly just 1st, 2nd and reverse. Usually have to run them way over filled with fluid because of standing the vehicle straight up and down. Also sometimes have to grab reverse under throttle to prevent flipping over backwards. Have any build recommendations for something like that?

I'm in the uk and trying to build a th400 for my 1000hp nissan 300zx and need help sourcing the parts I will need etc. I was hoping this would be something you could help with ? That's assuming you ship to the UK.

Do you have a 1200hp - 1500hp formula you could share with us as I am looking to moving from 1100hp glide to a 1200hp -1500hp TH400 as motor now making 1400 at the flexplate.

Do you sell machined direct drum piston

What torque rating for this build

Hello friend, I saw your video and I would like to get a question right, I took my th400 transmission to be repaired but it did not make the third change, I already changed the governor, modular, converter, and it continues the same, now to your great experience what will be the problem for which Does the third change not make the transmission? please help

In the video, you mentioned something about a "vent fitting" and "cooler lines." I assume the cooler lines are a reference for a trans cooler correct? As for the vent fitting, I'm not sure if you're referring to an overflow tank, dump valve or something else

Got my case in the local parts washer after your case prep mods. Ive got a couple quick questions that would result in having to order a few more parts. For a th400 that will get hammered on by small ls truck engines, should I do the case saver and spiroloc ring? I'm just cheap and like to have fun. Next is there a pro and con of the spiroloc you showed during the case saver part vs a thicker snap ring? Or is it more of playing with clerances thing? Last one of the night. I know you turn down the o ring and bevel on the output shaft, you have a lath right there. If one had to pay someone to do that would it be better to just remove the o ring and buy one of the beveled sunnex yokes in 1310 or 1350? Killer video again. Im loving the th400 vids, definetly building my confidence to just do it. I owe you some beers or a clean down south core the next time I'm up in Maine.

I need one of.the 4l80drum for a turbo 400,,can I buy one from you???

how long will a pump last with a trans brake? I read somewhere that the transbrake is very hard on the pump will it last 50 passes will it last through a week at rocky mountain race week....what's you take on the situation......thanks love your videos

Been watching your videos for awhile now and I’m currently building a TH400 with transbrake but I built the transmission off a video that was removed from KZfaq but i used a reverse manual valve body and cut out the correct passages and blocked off one channel I bought the correct spool for the selector, separator plate and gaskets, and external modulator valve for trans brake but my issue now is in the video the guy removed two spring valve assemblies that were next to each other and put 1in freeze plugs in them but the holes are not big enough for that so would I be ok to leave the shift kit parts in the valve body or can I find a different plug to block off the ports? I’ve done extensive research on it and keep coming up with nothing and you are very knowledgeable about th400 and seem to know what works and what don’t any advice whatsoever is appreciated thanks!!!

Hello Shawn, I follow all your videos and very much appreciate all the help you have provided to prepare me to build my TH400. I have the Hipster engine braking valve body and BTE bellhousing already and just looking for an overhaul kit for clutches gaskets etc. I would like 5/5/4 clutches, do you have any opinions on a good complete kit rather than trying to price something together? I realize I will still need a few additional goodies such as case saver etc. The goal is to be safe to about 800hp and I am looking at the FTI F4019-4 kit right now. Any insight would be appreciated. Rob

I'm wanting to delete the vacuum modulator and remove the governor on my street strip th400 while using the stock valve body what mods are needed to accomplish this? Thanks

You got the best videos on the th400...im building one for my drag week car.. other then the pump mod on one of your videos Do you know how to make the pump live on the street with a trans brake ? I hear it's kills them in a few thousand miles ..

Whats your 800/1000 HP build cost ? Been through the ringer with my Chevelle and transmission shops !

Now would this be acceptable for a dyno tested 510hp, or will I be better off leaving it as is, I got to fix reverse any way so I figured wile I got it apart will it hurt to do this?

Awesome information man have a question for you i have a 700R4 trans can i rebuild it and make it strong enough to handle 800 hp or not just curious

I just put 1 of those exact models in my 73 Camaro. I love it but wish it didn't shift so hard 1st to 2nd. Maybe it will last longer that way. Let me know if there is an easy way to soften the 1-2 shift a little. 600 HP 434 dart engine.

i have a th400 in a 6.2 diesel k5. I have a lot of engine roms and I get little power. What could be failing?

So what would be the best way to burnout if i have a manual automatic? Can't start burnout in second for that reason.

Shawn - Still waiting on parts...?

Hello. So im on final assembly and had a question. So i pretty much followed your instructions to a tee but im going with the auto shifting vb with the mods you suggested. Question...Should i run the engine braking band? Also is there any mod to do to the rear accumulator for the reverse band?

Will a th400 with the mods to the pump and valve body withstand long highway use?

hey man is the ROSSLER TH400 XHD WITH 210 first, 1.4 second and 1.1 Third good? also what stall would you recommend for a 1000hp wheel hellcat, running a 50 tall tire, 4800 race weight

Hey Mountain Garage. iv'e got an early TH400 i picked up and had been sitting outside and may have taken in some H20. I think i heard you say if one takes in water it's not worth overhaul, should i open it up and see how bad it may be? What do you think ?

👍

How much do you charge to have a th400 rebuilt if you are rebuilding at the moment? I would love to have my transmission rebuilt by someone who has a passion for transmissions

Hey is it possible to build toyota 8spd to withstand 800hp?

any suggestions for building something like this cheap. I know 1000hp and cheap shouldn't be in the same sentence. But it would be cool to see something someone who doesn't have a bunch of extra cash could build.

What clutch pack would you use for 1100 hp. I was going to use alto power packs with all the mods and a coan transbrake. Can’t find anyone who has them in stock. What would be the best alternative.

What will a stock 400 handle. I'm making about 550 on a stock transmission and Wondering if it's still safe or if I should be worried

So stock input main and output shafts are fine upto 1200hp ? Is this correct no need to change to billet ?

Can I run this setup with the factory vb and a shift kit ?

nice video ....how much hp 4l80 hub rated?

Stock drum input intermediate and output shafts all good for 800hp?

Where are you located? Sounds like I need you to build me one. Great video. A lot of great information here.

Do I use spiral lock if I'm running a transbrake?

Part number for larger snap rings?

Hell I'm still trying to get a solid answer on how much a bone stock 400 transmission can take.

Can it handle high speed(100-120) for a couple of hours?

Hi Shawn, I'm in northern NY and I'd like to have a 400 built by you. I'm getting my hands on one soon. How do I contact you for a quote of this build? Running ~600 but want room to grow

do you do rebuilds for customers? if so where are you located?

My transbrake sometimes won't engage but I can hear it click

i cant use the oem 4l80 hub on my th4oo 800hp turbo ls...cant hold this hp..?

Part number for spiral lock?

Thanks for the great overview. I have a TH400 in my car kzfaq.info/get/bejne/m5l4iJydmMqWnoU.html I built this 12 years ago for a close friend and he took care of acquiring the transmission and got it running so I dont know what's in the trans. I have the car now and do plan to disassemble the TH to inventory what upgrades where made (I'm sure it has stock shafts). It does has a trans brake, 2800 stall and the car is 2000lbs with me in it. Since it's a procharger it will not have a ton of low speed torque but I want to pulley the motor for 1100hp on the street. It does hook pretty good on a few spots I play at set at a proven 800whp. Any gut feeling on how dependable this combo will be built how you have outlined?

My friend runs low 420s.they refresh it once a year.

do you have a website or a number to call

How much is it to rebuild a th400

Next, do a 2000 horse one. hehe

Sounds like a 4l80 is about the same but with another gear. For us street guys

my trick had a friend worked at gm pwr train 1970s i got caddy cvy 400s cheep cores 20.00 ea from boneyards buddy got me output shaft& output 6"houseings wala build a hot chevy th 400 sell in local hot rod paper 500.00 ea all day long for a 50.00 investment