Mountains Garage: Popular Questions, Transmission Fluid & Slip Yoke Conversion

[@MurrayLewis-k3i]

Best explained Turbo 400 Transmission info ever !!

[@elsdp-4560]

Thank you for sharing.👍

[@unfriendlygaragenw2117]

So i bought a fully splined slip yoke before i did any research, if i grind rhe shaft like you is that ok to use or is a counterbore slip yoke still prefered

[@mountainsgarage]

@@unfriendlygaragenw2117 Just grind off the o ring groove and you are good.

[@bigtires100]

I've been watching videos on the th400 and you are the ONLY one who explains how certain mods affect the transmission, so I have a quick question. If you're dual feeding the direct clutch should you drill the 1/16" hole in the drum for centrical bleed off even if you aren't using a transbrake? Will it hurt anything if you DO drill it if you're not using a transbrake? Thanks!

[@mountainsgarage]

Thanks! Drilling the 1/16” hole is always a good idea on anything that will be accelerating at high RPM, it helps prevent centrifugal apply and burning of the direct clutches when they are not applied.

[@Mark-mz1zp]

Off topic; what stone and grit do you use to flatten the valve body? I am rebuilding a th400. Thanks!

[@leor838]

If I remove the bolted-on yolk off of a th400 is there any reason to have to grind off the o-ring groove when using a new slip yolk? Thanks Shawn

[@dobermanracing]

I want to say thank you for all the content and knowledge you share I have a th400 that I am putting into a tube chassis rock crawler. I am meeting it a Ford np205 and I have to change the output shaft to to a longer one. Your videos have been a big help in reducing the fear of diving into a transmission

[@cfmechanic]

I got a buddy with th400 manual valvebody with transbrake he's whining that he needs dexron 6. Said because the kit doubles pressure that he need to run synthetic, curious how important that is.

[@mountainsgarage]

If Old Wives built transmissions, this might be their tale. Just make sure it’s full of something, but pump wear with increased pressure is a tale.

[@carltotillo8301]

Do you know if you can put a TH400 output shaft on a TH425?

[@mountainsgarage]

A TH425 is front wheel drive.

[@carltotillo8301]

@@mountainsgarage Yes I know. I am thinking about making a mid/rear engined car with this engine and trans setup.

[@pjl1919]

Would this be the same for a 4l80e to convert from fixed to slip yoke ?

[@toddaaron4694]

Enjoy your videos. Keep up the great tech

[@AllanScott-bq2kr]

I change a 350 turbo and put another 350 turbo in now driveshaft won't slide in all the way can I tap it the rest of way

[@AllanScott-bq2kr]

My slip yoke won't slide on another 350tubo transmission why not

[@earlpretlow9958]

Is this true for 4l80e too?

[@jamieknight9636]

Thx for the vid Shawn, I've been running a 46 grade hydraulic oil (because its free) with no problems, I see the low viscosity Hygard is 32 weight, what differences do you think I'd see between using the either? maybe stall speed ?

[@mountainsgarage]

Hi! I would guess it will tighten up the converter some.

[@MR.TOPNOTCH103]

I was told you could just take the o Ring off and put a slip yoke on.

[@mountainsgarage]

A counterbored yoke yes, eliminate the problem by removing the o ring groove.

[@MR.TOPNOTCH103]

@@mountainsgarage Someone told me that you can actually just remove the o ring and not have to shave anything down and get the center board yoke

[@mountainsgarage]

@@MR.TOPNOTCH103 It will work, but travel will be limited.

[@leesanders8824]

The bolt on yoke caused me a leak that I had no idea about for quite a while until I watched one of your videos. I sealed up the yoke (gonna get a new one without the hole) and no more leaks. As best I can tell the output shaft has no o-ring groove. The transmission came out of a pulling truck that I had built. As best I remember, the output shaft has no hole in it.

[@cumberlandfleetservice6152]

Any thoughts on doing some in depth 4L80E or TH350 videos?

[@mountainsgarage]

I probably will sometime. Thanks!

[@petermullin5387]

I had a similar discussion with a snowmobile mechanic about 2-stroke injection oil. He said the only bad 2-stroke oil he was familiar with was none. Said his son ran the cheapest Walmart 2 stoke oil in his race sleds with no problems. I run Amsoil because the exhaust smells better and I get fewer fouled plugs.

[@drewlaw8191]

Can you go over an Extreme Automatics TH400 1+2 Clean Neutral valvebody or even just one of their valvebodys potentially in the future?

[@mountainsgarage]

Good idea! Thanks!

[@grannysgarage8101]

Shawn can you please make a video on th400 governor information/mods to adjust shift points. thanks

[@MHolt3573]

This made my night

[@keiththecarguy1967]

Kind of off topic, wanting to rebuild a powerglide, I know your not a big fan. This is a cruiser application. Can you recommend a book, and is there anything you might heavily recommend that need to be done? Thanks for the videos, learning alot.

[@mountainsgarage]

I have some Powerglide videos in the playlist on my channel page. Thanks!

[@truckladders4104]

Great Video Shawn I really enjoy your work The videos are both entertaining and educational, This is very important for technical training. Just the facts can be really boring and yet important. Is it possible to group all your TH400 videos into a manual/library? I dont know much about You Tube but it would be great if a viewer could see all your TH400 videos in one group for learning and reference. Keep up the great work I learn something from every video and I have been a mechanic for 35yrs! Looking forward to more great content (

[@mountainsgarage]

My channel has playlists, look under TH400. Thanks for watching!!

[@vrg69]

More good info thanks

[@dhansen7235]

This was exactly in my head but i didnt want to ruin a very low mile transmission.ive used the grinder lathe method long before i had a lathe. And still use it. This was awsome.i dont care about the grass...

[@MattD01]

Have you done, or will you do a rebuild on a 700r4 transmission? Maybe specifically for a 500-600 horsepower "street" car with a little 🤏 hit of nitrous. and possibly talk about cost. Or should one just opt for the th400 and not worry about overdrive. Asking for a friend! Lol thanks!

[@mountainsgarage]

I believe you answered your own question! If you are cruising to get ice cream the 700R4 is a good choice. I build them for that.

[@MattD01]

I thought so.....just needed that reassurance 🤣 thanks man. Hey I really appreciate your videos and info that you put out! - Matt from Lexington, NC

[@BigMikesGarage]

I spy a th400 output shaft chucked up in the lathe.