Transmission and Transfercase


Ford has so much to offer!

A Borg Warner T-18, NP-435 or even a ZF with their low granny gears would have been nice for the van, but since those have the shifters protruding from the top cover, that would put the shifter in the engine cover. So I was stuck with using the original tranny. Of course that doesn't mean it has to stay original :)

My dad had a tranny custom built to go in his 1966 Econoline pickup. After having it sit brand new in the shop for years, he changed his mind and realized an automatic would be a lot easier to hook up and to drive. The original plan was to convert the truck from a 3 speed to a 3 speed with overdrive. But since it had the column shifter, we had to use parts from both transmissions to make the conversion. Now that my dad wants to use an automatic, this makes the perfect transmission to use in the van with the divorced NP-205.

Legendary muscle car shifting, for the 4x4!

To make the tranny work, we had to use a newer 4 speed case and use the original short 3 speed aluminum top mount tail shaft housing. The difficult and expensive part was to have a custom output shaft made to work with the newer case and non-original tail housing. A company named K Bar S out of Las Vegas specialized in building custom parts for older Ford Broncos. They had to cut the end of the 3 speed shaft and weld it to the front half of the 4 speed shaft. Somehow they welded it by spinning the shafts in opposite directions at incredibly high speeds so that friction melted the steel (red hot) which is then fused together under high pressure. After that the shafts are spun again at high speeds (in the same direction) to make sure that the shaft turns perfectly true. Unfortunately the company is no longer in business, so I am hoping I never break this output shaft.

Short, lightweight and STRONG!

Thanks to the original '66 Econoline tail shaft housing, I really like how it mounts the transmission from the top, instead of having an underlying cross member. Better ground clearance and nicer looks too. The original tranny in my van was equipped with a slip yoke rear driveshaft. This tranny now has a fixed yoke which will let all three of the drive shafts be of the slip-shaft type. Also when I get around to installing everything, since this transmission is of the same dimensions and bolt patterns, the swap will go really smooth since all of the clutch linkage is the same too.

Transfer case:

The heart of four wheel drive

Since my transmission was never available on a factory four wheel drive truck, I decided it would be easier to use a divorced transfer case rather than have a custom tranny to t-case adapter made. I searched the internet for a good deal on a t-case and found a seller on eBay who could get one for pretty cheap. A month or two later he found one and it made the journey all the way from New York. supplied me with a nice bearing and seal rebuild kit. Some sanding and grinding on the case and two cans of spray paint later it was ready to be stored suspended in its natural position until the time came we needed it.

From a Ford, Into a Ford

This transfer case was removed from a 1976 Ford F-250 Highboy 4x4. Luckily the guys gave me all of the U-bolts to go with it and also the yokes are in nice shape so I am going to reuse them. The input is a 1310 and the outputs are 1330's. They should be big enough for what little off road use I'll see. Many people think just because it is divorced and has the round three bolt cover on the rear, that it must be a NP-205. Well it turns out the cover is there to do just that- cover the idler shaft. There is also an NP-200, NP-201 and an NP-202 (which are also divorced) that have these same covers.

The transfer case was fun to rebuild. It is small and has a lot of interesting parts inside. Much of which just needed to be taken apart and properly cleaned. My dad and I installed new bearings + seals throughout and I primed the inside Rustoleum red to help oil flow. After assembly the outside got the red primer also and then the black enamel.

One problem the case had was a broken off stud in the top mounting pad. Unlike Dodge and Chevy divorced 205's, the Fords mount only from the topside, so the hardware better be grade 8 or better. The broken off stud was challenging to remove, but with a drill, an easy out, and a torch, the threads were good as new. We made our own studs from 5/8" grade 8 bolts by cutting off the heads and then threading them to fit two fine thread 5/8" nuts and jamming them together.

I decided not to do a twin stick conversion since there really wouldn't be any point in needing it in a van. If I need 2wd low range then I'll just shift it into 4LO and not lock the hubs. Seems easier than cutting and grinding notches on my shift rail interlock pins. And I really don't think I'll ever break an axle due to their size and my tastes for off-roading.

With little risk comes a big reward

Since I bought this over the internet from New York, I really had no idea what it was like or what the gears were like inside. Had to take a chance for a good deal I guess. And a good deal it was since all of that oil seepage helped protect the bare cast iron from the many years of northern road salt. On areas where there wasn't any oil, only minimal surface rust formed. There was one spot on top where scale rust (probably due to salt sitting on top) had dug a slight dent in the case. I decided a nice fix would be to use JB Weld. Using some water and your thumb is the best way to form it into tight areas.