Just picked up a th475. Guy had it advertised on marketplace. Said I could have it if I hauled off the motorhome it came in. So I just hauled it all off. Found a bunch of good info here. My goofy question is, thoughts on using the th475 over the th400 I am using. The th400 is currently out for an engine upgrade, a 500 caddy. All going in a 63 ford I just picked up a DNE2 overdrive unit so the next question is are th400 and th475 output shafts the same? Oh. The motorhome had 79k miles thanks.
Some may have a bolt on yoke as opposed to the standard slip yoke past that it's all about the internal gears.
I think that the output shaft has some differences, but replacement output shafts are cheap, and easy to get, in case it doesn't just go together.
Thanks. I know externally they are the same. Both my trans have bolt on yokes. The OD unit I bought is threaded for one edit. The 475 has a parking brake.
I will set both on a table and check em out. I would have to change the 475 (if it’s different spline) to use the OD unit. The current TH400 is great. The 63 ford is in the upper range of what the 400 is rated for. The 475s GVW range is well above the weight of my 63. The noisier gear set isn’t an issue.
I recall reading something recently that indicated that if you swap over the extension housings to a 2WD / passenger car style housing for a large diameter yoke it can be used without issue. The slip yoke required was available from Denny's and slid over the output shaft O-ring. I can't speak from experience though.
Had to dig into some archives from ten years ago. Usually used in a motor home or heavy truck. This is what I came up with. TH475 is the same as a TH400 externally. Most of them had a drum emergency brake on the tail shaft as they were used in motor homes, C50 or bigger trucks, and busses. Might run into drive shaft issues if the drum brake is present. Internally they are different. They have strait cut gears instead of angled or sun cut. They are much stronger. They tend to have a whine noise when running down the road because of the strait gears. As the others said you may have a big truck park brake on the back of the trans. You could pull it apart and change extension housings and tail shafts though. A gasket kit with seals doesn't cost very much and you don't have to break it down to the last little piece.
I thanks. I will pull off the drum and tail housing and compare the outputs and see if the OD unit fits
This might give you some info on the Doug Nash od unit. Someone posted the pages of the instruction sheet. I missed out on a motorhome for pocket change a while back that had a gear vendors OD in it. Getting it home would have cost more than the mh did. https://bangshift.com/forum/forum/b...ses-overdrive-dne2-us-gear-dual-range-revival
I have one out of a cube van, no drum brake and it has park, my buddy has one just like it, although I don't know what it came out of.
This one was 80 miles away but my flatbed is not running good enough to tow anything. Price was less than the going price for the OD unit.
Do you have any clue if the valve body on the 475 is set up different than the 400. I was advised by a HAMBer to add a shift improver when I originally set up the 400. It definitely shifts too soon into 2nd.
I ran into this issue just a while ago! The TH475 is noisy but makes up for it in power Additionally, the output shafts are the same 32 tooth spine and diameter between the two. The TH375 has the TH300 splines. Tail housings are different and the TH475 has a much larger outside diameter yoke (1410 yoke) I called Denny's Drive but the rep said they no longer carry these yokes. I would instead have to change the entire output shaft and tail housing to make it a slip yoke.
I’m using the bolt on Overdrive so the trans is good. The issue may be with the overdrive. It’s output is drilled and tapped. But the output shaft looks to be about 3/8 of an inch short on the inside the yoke.
So slip joint not available, what to do? Make/use a two-piece driveshaft. @anthony myrick are you making a hauler or? If a hauler/truck, two-piece solves the worry, right?
Yeah, these are for high-torque, low-rev heavy haulers. You might need a governor for a more appropriately sized vehicle. A shift improver will do exactly that, but you also need to move the shift points up.
A wise choice. A bone stock 500 can produce 550lb.-ft. of torque. With a handful of upgrades, it can lay waste to most transmissions, if not appropriately properly prepared.
The 500 ran great when i got it, however I couldn’t leave it alone. Everything was still in spec on it. We did a fresh hone and crank polish. New bearings and rings. Slight mill on the heads. Better bump stick and springs. The weight on what it’s going in is 7k empty. Hopefully the 500 will be an improvement over the 350. I have a 2 piece drive shaft. I like em on stupid low vehicles. The first section of drive shaft is only about 18 inches long. Adding the OD unit will significantly shorten that unless I shorten the 2nd shaft. I think a one piece shaft would work if I have to use a slip joint for the OD unit.
here is the yoke pushed all the way up on the OD unit. More like a 1/2 inch. Will look up 400 yokes for options
I have cut-down bolt-on yokes, to reduce the overhang. As long is the seal is on the polished section, and not riding up on the radius, it should be good.
If it’s ok. I could machine a spacer to take up the slack for the bolt/washer. The seal is ok on the machined surface and the yoke seems to bottom out correctly.
The Jalopy Journal
