Mountains Garage: TH400 Or TH475? Let’s Find Out!

[@stuartcookie133]

Here on Long Island, N.Y. a Turbo 400 core not full of water is worth around $300!! A good buy indeed!!

[@anthonypblake]

Gives me motivation to tear into the 90 FKA I've had sitting in the shop for a few months. Hope it is the gem you found

[@garygriffin3114]

Hello Shawn, Like always I enjoyed your tear down of the T475. Just wanted you to know the value of those parking brake drum assemblies you remove from the tail housings. I have a 1973 C60 and a 1974 C50 and both have the drum parking brakes on the end of the transmissions. I just was looking for a parking brake cable and when I seen used drum assemblies on ebay going for $350 I thought I would give you the heads up. I'm a little like you as I have many projects in the works at the same time. I find I am dragging out finishing them due to time constraints. I never have enough time. Keep your videos coming I always value your view of things.

[@mountainsgarage]

I have scrapped a dozen at least, hmmmm, Thanks for the heads up!

[@ramjettpolygon1415]

The Transmission would have to handle A 2018 GM L-86 W/ a Texas speed upgrade bumping up the h.p. from 455hp to the 525ish h.p. ball park Thanks again for sharing your knoledge

[@cesalie2]

Thank you for these video’s, enjoy your work and knowledge. I have an 1982 Airstream Motorhome on a P30 chassis with the TH475 transmission. I am considering the addition of a shift improver kit and wanted your opinion.

[@mountainsgarage]

Go on the crankshaftcoalition TH400 page and you can do your own shift kit. Thanks for watching!

[@mrrobot545]

You find all the nice stuff. I got nothing around here.

[@davidcallahan5157]

Like a box of chocolates!

[@ramjettpolygon1415]

I've just recently discovered the video s Your doing .And I gotta say for a guy Who's taken the interest in understanding How a trans mission functions enough To acquire the knowledge you have By "trial & error" I feel deserves more Respect than a formally educated expert For the simple fact that you owe nothing Of credit to anyone but yourself not for what you" think you know" but what you "KNOW" from experience. While keeping a "level head" in acknowledging this info is only an opinion. Awesome! I tip my hat. So, maybe I could get yourself taught opinion on a concept of mine in Wheighing my options that for me is Both uncharted and abstract transmission territory. I'm restoring/Re-powering & re-engineering my 50+ yr old boat That I'm abandoning the I/O it Had originally for an Inboard direct drive system W /a transmission. I could go with The standard marine trans. , But the Boats pretty heavy .(24' fiberglass deep-V) That's probably around 3800 to 4200 # So having 2nd gear pulling itself up to Breaking over it wake onto a plane Before 3rs @ 1:1 would help it's performance. You think the idea is reasonable ? Or would I be installing a "transmission grenade " since spinning a propeller a those RPM's is like "Putting a corkscrew through concrete" Can a strong TH475 take a shift in Those conditions without breaking ? Thanks for your time, Paul V. Construction by day , freelance boat engineer by night.

[@jasonjennings5833]

You got a smoking deal on them.

[@sb18436572]

Great information. Any turbo 350 builds coming

[@mountainsgarage]

I try to avoid them. They are weak, then they became the 700R4. Then the 700R4 didn’t last so many were converted back to TH350s. Hence most have a zillion miles on them and are wore out. But if one comes along I will cover it. Thanks for the comment!

[@sandyman541]

Lucky to only have 3 bolts break on you. I'm still soaking my bolts and dreading the moment I tackle taking them out. It's been super hot and humid here in SC. Any other suggestions on how to get them out without breaking them off besides penetrating fluid,, heat around the bolt, hitting the bolt heads with a brass punch and hoping to get them free to move back and forth?

[@mountainsgarage]

Those are my methods as well. I want to get a infrared bolt heater.

[@sandyman541]

@@mountainsgarage ahhh thanks for jogging my memory. I have a coworker that has a bolt heater he uses on exhaust work. That should be better than heating, hitting and cooling..the heat really needs to penetrate the oxidation between the steel bolt and aluminum case....don't ya just love how different metals interact? Lol

[@DoItMyselfGarage]

Just got my GTO running with the TH400 which I rebuilt myself. Was encouraged by watching you rebuild so many of them. Unfortunately, it seems to only be shifting via the governor(yes, has all three gears). The adjustable vacuum modulator is holding vacuum just fine. Held 20lbs over night and isn't leaking any fluid out of it. I have plenty of vacuum on the line as well when the car is running. I rebuilt it almost a year ago before putting it in the car. I've read that maybe the valve behind the modulator might be stuck from sitting. Would this be the first thing you would check? It should just come out with a strong magnet once the modulator is removed right? Thanks in advance for any help!

[@kyleoden7656]

Could you put this in a 4x4 behind a np205

[@gregsmith9457]

👍👍👍

[@davesperformance88]

What horsepower level do you think the 16 element drum is good for also the 3 clutch intermediate good for?

[@mountainsgarage]

3 clutch intermediate is said to be good for 1000+, but I usually still add one clutch and steel using the 4L80E stuff. The 16 element, if not abused, in a lightweight vehicle would last surprisingly long, but a 34 element sprag isn’t a big money upgrade.

[@leesanders8824]

Question.... What could make a th400 whine in low? Reverse manual setup,no noise in second or third. Not loud and no noise in park, neutral or reverse. Fluid level is full. Can't hear it in gear idling but when accelerating and goes away when shifted to second.

[@mountainsgarage]

Maybe just gear reduction? You can usually hear them during low speed maneuvers. I can hear my old service truck now!

[@leesanders8824]

@@mountainsgarage thanks for the reply. If it gets worse I'll worry I reckon. I really enjoy pretty much anything you do. You explain things well with whatever pertains to the video. I look forward to your content and am glad the 475 worked out and I hope the other does as well. Good buys

[@JOMaMa..]

Broke the dipstick off in papas rear

[@MHolt3573]

First.