TH400 Part 7. Make Full Manual from Stock Valve Body.

Modding the Valve body here. turning stock th400 valve body into full manual valve body as well as drilling and plugging holes for firmer shifts.

[@brandonheckathorn3270]

Excellent video! I've been having issues with mine after doing a b&m stage 2 kit and plugging the hole in the 1-2 bore. Worked fine n/a, then added a 68mm and wont shift above 10 psi, love the video! Going full manual!

[@gregg4164]

Had this done to my 400 in my truck back when i had it rebuilt. You can either manual shift all day or left it shift automatically in mine. You can hold any gear without tearing it apart which is great for a heavy truck or towing purposes.

[@WrenchAvengers]

yea that is what i wanted to do with mine but i has an issue with the governor in my trans so i just opted to go full manual instead of fix it.

[@phonypony5.0]

By far the best vid i seen on doing this

[@WrenchAvengers]

thanks man i appreciate that!

[@K1LL3R_M1LL3R]

Yes. Very much the best

[@jordansmith8467]

Good info. I'm a new builder myself

[@nw8730]

Thank you for your video. I am a big DIY guy Engine and Transmission. 8-28-2022

[@johnmcdonald6320]

rad, good job

[@garrettcarpenter3319]

I modified a 400 valve body like you and it worked one time and i can shift into first gear its like first and second gear is the same but will shift into third gear

[@keithsheffield7181]

Love the video, I am going to be doing this to a 400 behind a Cummins 4BT. Did you leave the governor out since it’s not being used or is it still in there just spinning around?

[@WrenchAvengers]

Yea the governor was left out since it's not being used.

[@blowngoat]

Did all this but have no third gear. Got the transmission with no other info. Went through it and all looked well. Any ideas? Governor deleted and don't need vacuum to the modulator correct? Boosted application any how.

[@tonybaainy920]

hi i need your help with the th400 I've done modifications on my th400 vb as it shown on the website and now it's full manual but im facing a problem all the gears have about 175 psi pressure except 3rd gear the pressure drops to 70psi and drops on the torque line from 60psi to 10 psi

[@havocracing6019]

Shouldn't you be able to use hipster transbrake on this?

[@DWBmotorsports]

Curious as to what size set screw you used for the governor tube block offs?

[@WrenchAvengers]

I'm not completely sure but looking up online says 3/8-16 so that is likely what I used.

[@K1LL3R_M1LL3R]

Idk about governors, but I used a 5/16 to block the port going to the accumulator spring. Had to tap, shave the head off a 1" long bolt, grind a slot in it to screw it down, below flush

[@72troy455]

Would you know why my kit says to drill a 8th inch hole into the channel next to the 2-3 accumulator well? I'm using a Fairbanks 20812 kit.

[@WrenchAvengers]

is it asking to drill a hole in the valve body or in the separator plate?

[@K1LL3R_M1LL3R]

I would like to know, as well

[@picco68]

hey great info need so advice, when i put the flats on the valve there is a small mark on the other surface will this effect things ???

[@WrenchAvengers]

Like a scratch in the face of the part of the valve you didn't grind on? I doubt that would cause much of an issue depending on how deep it is. I'd inspect the valve and the hole in the valve body it goes in make sure there are no large burrs in there it could get hung on. Small scratches should effect anything but a deep gouge may be a problem.

[@picco68]

@@WrenchAvengers ok great thank you for the fast response i had to cut the vb to get the valve out as the sleeve would not come out i will try again with the new vb and use more caution

[@jeffs9003]

so if im just modifying the 1st gear mod, it it still a good idea to block off the 2-3 sift acumilator an leave spring out?

[@WrenchAvengers]

Blocking the accumulator and removing the spring will make the shifts more firm. Doing that is more to supplement the drilling of the holes in the plate. You could take it or leave it. But one thing to think about is the faster the trans mission shift the less time it drags on the clutches. This will increase the life of the clutches but the pice you pay is a harder shift and some people don't like being shaken every time they shift.

[@gregg4164]

Hell thats half the fun. screeching the tires at every shift is a high schoolers dream. One i can still say i enjoy today. Ha.

[@72troy455]

The valve body itself, looks like in a channel next to the 2-3 accumulator well.

[@WrenchAvengers]

hmm. i cant find the instructions online so I'm just not sure why they would do that. possible they do something strange with the separator plate that makes them have to bleed something off. I'm pretty skeptical of that because no other kits I've seen have you drill a hole there. I know you've already purchased this kit but i would suggest to you the Transgo kit. it will dual feed the transmission and is one of the better kits out there. I do understand you purchased this one already and probably want to make it work though. you may look up the instructions for the similar B&M kits and the Transgo kits and see what they have you doing maybe it will shed more light on what this kit is asking you to do. Only other thing i can think to do is maybe call or email Superior Transmission and ask them. They seem to be one of the main retailers of that kit so maybe they can help out or call Fairbanks if that is an option.

[@72troy455]

+Wrench Avengers Yeah I can't find any kind of customer support with this kit. I used it on a T400 back in the 80s and it worked real good. But that was 30+yrs ago and I can't remember exactly. The instructions have been copied so many times they are real dark. So the arrow just points in the vicinity next to the accumulator well. I'm wondering if its saying to drill the channel next to the well into the well itself. That's kinda what it looks like. I took a picture of the instructions and blew it up and it looks like a nail or a drill bit connecting the well to the passage next to it like its showing where to drill. I'm just not sure enough to drill it yet and feel good about it. Hate to booger it up. Everything else about the kit is straightforward and simple. The components seem to be high quality also.

[@72troy455]

+Wrench Avengers Been stumped on this for a month. It's become a quest now.

[@WrenchAvengers]

so let me ask this. what kind of functionality are you trying to get out of the transmission? full manual with no auto shifting or full manual in low 1 and 2 but still have auto in 3rd? if full manual with no auto you dont really need anything done to the accumulator well. just pull the spring out of the accumulator and go on. other option is to skip the step and go on and if it doesnt work as you think it should once its back in the vehicle to pull it out and try to drill it later. (i know its a pain but id hate to drill it out and it cause an issue. its easier to take the material off than put material back in.)

[@72troy455]

+Wrench Avengers The kit has 3 stages, 3 being full manual competition mode, then the kit added a 4th stage they call the Prostreet mode. It keeps auto shift in 3rd and full manual everywhere else. It was obviously added later, because it came with another set of instructions. Appears to be just a combo of competition mode and street strip. It retains the modulator valve where stage 3 eliminates it. The tranny is going in a 95 S-10 Blazer with about a 500hp SBC in it. I'm gonna bracket race it and cruise around in it also. I'm using a 3500stall and 4-10 gear in a 8.5 rear.

[@jromesmith968]

Thinking of doing this to my transmission as the car is a diesel. Have you had any issues with this set up? Cheers

[@WrenchAvengers]

No I havnt had any issues. It took some getting used to but it works great other than it does leak fluid. Ive never seen a th400/th350 that didn't lol.

[@jromesmith968]

Wrench Avengers . Mine leaks as well that’s for sure hahaha ... Do u have to block the reverse oil passage next to the support bolt for the manual valve body to work? Or is that for something different? Thanks in advance.

[@WrenchAvengers]

@@jromesmith968 yes you need to block that off. I go over that in one of my other videos. If your wanting to do full manual the would be good to go through those or go to the link I posted in the description of some of them. (Think it was crankshaft coalition) it goes over how to switch over to full manual.

[@mulletracing8787]

Are you running all the check balls?

[@K1LL3R_M1LL3R]

I'm only running 3 of them, per my B&M shift kit instructions. But also doing the 2-3 shift accumulator spring/tap modification

[@chadjanis86]

What did u do with the case check balls ??

[@WrenchAvengers]

you talking the check balls under the valve body? i go over that in the linked video (should be correct time stamp) kzbin.info/www/bejne/amGwm4JorbGkeas also most of what i did came from this site if you want to check it out lots of info there. and it shows check ball location. www.crankshaftcoalition.com/wiki/TH400_rebuild_tech

[@claypike6989]

Did you plug the dial feed hole in the plate. If so how did you?

[@WrenchAvengers]

No I didn't plug it in the plate. I plugged it in the case. That the hole next to the center support bolt. Both do the same thing either blocking in the plate or in the case.

[@claypike6989]

That’s what I fingered

[@jakestree1892]

What about the Modulator valve? Is it reused or plugged?

[@WrenchAvengers]

just plug it. i just put the modulator back in but didnt connect it to the vacuum line.

[@1pochek]

Hey man. I've got a question for ya. I'm wanting to do a reverse manual valve body on a turbo 400 tranny. I still want to be able to put it into 3rd gear and have it shift like normal ... do you have and links or suggestions on where to look to do that

[@WrenchAvengers]

well sadly as far as i know there is no way to keep auto functionality and have a reverse valve body. when going with a reverse shift pattern you cant reuse the stock valve body as i did you have to get an aftermarket one and searching around i can only find ones that are full manual if they have reverse shift pattern. i wont say that it cant be done but from what i know (witch isnt much) it cant be done. that is where i think the forward shift pattern and just modifying the 1-2 shift valve so the transmission doesnt panic shift is a good option. you can maintain auto but still hold low and 2nd if thats what your looking for. less desirable if rock crawling but im not sure what your application is. sorry i couldnt be more help.

[@1pochek]

That's about what I needed man. Thanks for the quick response

[@inscoredbz]

Does this manual valve body keep the band for second gear?

[@WrenchAvengers]

I left all the bands in the transmission. I would assume they are still used.

[@inscoredbz]

@@WrenchAvengers if you have engine braking they still work.

[@eddamonsta4887]

Can a rachet shifter kit be installed on stock valve body or do I have to do the manual valve body I have th 400 automatic transmission

[@WrenchAvengers]

you could use a ratchet shifter on a stock valve body. just be sure the shifter is able to be used with a th400 and forward shift pattern. you dont need to modify a transmission to change the shifter.

[@eddamonsta4887]

Wrench Avengers Kool thanks man

[@CristianHernandez-gk1sd]

Hello For the conversion to fully manual, is the vacuum module and modulator removed?

[@WrenchAvengers]

yea if going full manual there is no need for the vacuum modulator. you can buy a plug and plug the outside of the case or what i did was just put the vacuum modulator in but no vacuum line connected to it. i did put a rubber plug on the outside just to keep dirt and grim from getting to the diaphragm inside.

[@CristianHernandez-gk1sd]

@@WrenchAvengers and governor ,kikckdown ?

[@WrenchAvengers]

@@CristianHernandez-gk1sd if full manual youll remove the governor tubes and plug the ports like i mention in the video. so you wont need the governor anymore. (this is the reason i went full manual was i had an issue with my governor so i removed it all together). no need for a kickdown as its not going to work anyway. full manual means just that there is zero Auto functionality in the transmission anymore. i kept mine there to plug the hole but its not hooked to anything.

[@CristianHernandez-gk1sd]

@@WrenchAvengers governor just take off and put the cover back on?

[@WrenchAvengers]

@@CristianHernandez-gk1sd thats what i did and its been working fine lol.

[@PSYCHOT1CNINJA]

Did everything work smoothly after these Mods or did the trans have any probs?

[@WrenchAvengers]

aside from putting it back together incorrectly the first time it had no problems lol. truck has ran great for a while it has been in the shop getting painted and should be back on the road soon.

[@PSYCHOT1CNINJA]

@@WrenchAvengers I have the tci super street fighter auto manual and under high power the shifts giving me probs being boosted and still working with the vac mod And gov , so I plan to give this a shot so it absolutely shifts when told.

[@WrenchAvengers]

@@PSYCHOT1CNINJA yea if you dont mind having to always shift it then it should work out just fine. most people want to maintain auto functionality.

[@PSYCHOT1CNINJA]

@@WrenchAvengers awesome. Yeah I dont mind shifting , my last trans on my other build was full manual reverse vb and starting to really miss it Haha

[@WrenchAvengers]

@@PSYCHOT1CNINJA what is the setup on this build your working on?

[@midwestracer2003]

does this mod give you engine braking in all gears

[@WrenchAvengers]

From what I can tell yes it does.

[@ugd240000]

<a href="#" class="seekto" data-time="582">9:42</a>

[@72troy455]

The instructions are so dark ya really can't tell where the hole is.

[@shadowsedgegaming8652]

hey i done a 400 turbo with all the case mods the valve body mods but i have no first or third gears reverse works and second works third works if you pull shifter from neutral down you put in first nothing shift up have second shift on up no third

[@WrenchAvengers]

hmm. you got a pressure gauge on it to see if you have any line pressure in those gears? you can get a 500psi pressure gauge on amazon for like 20 bucks (i know because i have to do some troubleshooting myself) you can plug it into the port that is slightly above the shift selector on the driver side of the case. check out the pressure in each gear. im reading the engine needs to be at about 2000 rpm when checking the pressure. start there and we will see what we can figure out based on the results.