2WD M5R1 Fixed Yoke Tail Housing?

[ChristianEwing]

What's up guys, I am in the process of building a 2WD 1993 Ford Ranger, it has the 4.0 OHV and the 5-speed M5R1 trans behind it. The tail housing the transmission comes with factory is a slip yoke style setup that allows the driveshaft to be a solid one-piece shaft, and all the slip is happening at the yoke in the tail housing. I am trying to convert that setup to a fixed yoke on the trans and have a new driveshaft built with the slip built into the shaft instead. The reason is the truck I'm building is a very purpose-built go fast off-road truck with a 4-link suspension, pulling 25" of wheel travel, and I'm worried that with that amount of travel (especially at full droop) it's going to be putting a lot of weird stress on the tail housing with the factory slip setup it currently has at the yoke and it's gonna end up grenading itself. With the slip in the driveshaft instead, it can keep everything more happy and is very common in the go-fast off-road world.

Current problem...I pulled the slip yoke off the factory drive shaft and popped the copper plug off the end of it to expose the splined section of the yoke. I planned to machine down a 1.25" long steel slug that goes into the end of the splined section of the slip yoke that I'd drill a hole in the center of for a bolt to run through and then tig weld it into place so that the slug bottomed out on the end of the output shaft when the yoke was fully slid on (the idea is to not allow the yoke to go towards the trans any further so it does not destroy the tail housing seal) and then I was going to drill a hole in the center of the tail housing that I could tap for a 3/8" bolt to hold the yoke onto the output shaft and not allow it to slip in and out of the tail housing anymore. That's all fine and dandy and would in theory work great, BUT the output shaft is hardened steel and I can not get a drill bit to go into it to save my life. I have all the good bits, but I just do not have the tools here to make it happen. My only real option is to take this tail housing off and take it to a machine shop to have them drill and tap it for me and I don't want to deal with them if I don't have to.

My question is now that I've gotten into the weeds with this, did any of these M5R1 transmissions come with a fixed yoke tail housing setup factory from any other year or model vehicle that I can just source and buy that bolts on? I don't know much about these manual trans since I do not typically use them for these applications, I usually deal with TH400's for the trucks I build and they have aftermarket bolt-on fixed yoke tail housings options you can buy for them. What makes the issue worse, is this truck is a single cab and there is no carrier bearing or option to add a carrier bearing into the equation. If I could add one I'd just leave the slip in the yoke and add the slip into the main shaft on the two-piece driveshaft but I do not have that as an option and the tail housing needs to have a fixed yoke to work for my specific application

 

[Snoranger]

The late 89 and 90 2wd BII had a fixed yoke on the both the M5OD and the A4LD. It was only available behind the 2.9L so you’ll have to run the 2.9L gearing.

The way Ford accomplished this was with a bolt on adapter that looked like a slip yoke with a 4 bolt flange similar to the transfer case output. The output shaft was center drilled and threaded. I’ve only ever seen 1.

 

[RobbieD]

The late 89 and 90 2wd BII had a fixed yoke on the both the M5OD and the A4LD. It was only available behind the 2.9L so you’ll have to run the 2.9L gearing.

The way Ford accomplished this was with a bolt on adapter that looked like a slip yoke with a 4 bolt flange similar to the transfer case output. The output shaft was center drilled and threaded. I’ve only ever seen 1.

The B2 driveshaft is the top one. The adapter flange has a large bolt that threaded into the transmission output shaft.

Probably hard to find the flange to begin with, then there's the problem of finding a transmission with the output shaft that's drilled and tapped for it.

B2's with a 2WD transmission are kind of rare; most had a dummy transfer case.

 

[CamTheHedgehog]

most had a dummy transfer case.

That's a thing??

 

[RobbieD]

That's a thing??

Yes. The Bronco II was first available as 2WD in the '86 models, but they were built with the 4WD type transmission and a dummy t-case with only a rear drive shaft was used.

My understanding is that the B2's that came with a true 2WD transmission was late production '90 models.

 

[85_Ranger4x4]

That's a thing??

Yeah, rather than design a longer driveshaft they designed a whole nuther t-case (BW-1359) that is just a dry hollow case with a input shaft, output shaft and a splined coupler connecting the two.

Transfer Case Identification - The Ranger Station

Transfer Case: A mechanical device with the capability to send power to a front driving axle as well as a rear driving axle. Transfer cases drive the front output shaft with either a geartrain or a flat Hyvo-type chain. Transfer … Continued

www.therangerstation.com

And then later on they designed a longer driveshaft.

 

[CamTheHedgehog]

Yeah, rather than design a longer driveshaft they designed a whole nuther t-case (BW-1359) that is just a dry hollow case with a input shaft, output shaft and a splined coupler connecting the two.

Transfer Case Identification - The Ranger Station

Transfer Case: A mechanical device with the capability to send power to a front driving axle as well as a rear driving axle. Transfer cases drive the front output shaft with either a geartrain or a flat Hyvo-type chain. Transfer … Continued

www.therangerstation.com

And then later on they designed a longer driveshaft.

This feels like..... classic ford.

Hey Detroit, ever heard of Occam's razor?

 

[RobbieD]

I honestly believe that it had more to do with trying to keep some weight, and to keep that weight as low, as possible in the 2WD models.

It seems that it was more expense and effort to make a special t-case for just one model, versus just robbing the 2WD parts bin for the transmission and making a shorter drive shaft.

It was said at the time that the market driver for a 2WD B2 was "soccer moms" and others wanting a neat, cute little commuter and errand truck. Stripping the 4WD drivetrain completely for a 2WD one (think front diff, too) raised the CG (center of gravity) a little and made truck all that more "tippy".

The way that Ford did it, doesn't make any sense until you consider that it may have been trying to minimize the liability risks, of average or marginal drivers doing very stupid things on paved roads.