Any Ford 4X4 Guys Here?

[Heffalump]

I just bought a 1982 F150 4x4 with a 300-6, SROD 4spd, NP208 (I think.) I want to get rid of this POS transmission and swap in either a T18/19 or NP435. I've been perusing the Ford forums, but there is SOOOOOO much information there that it is almost impossible to find anything. There are about 20 threads with good info, and 56,000 threads that say "go do a search, newbie!!"

Anyhoo, what I'm putting together is that I can either find a 4x4 4spd and keep my existing t-case and drivelines, or I can use a 4x2 4spd with a different t-case, which will cause me to have to swap drivelines. If anyone has ever done this before, I'd love to hear opinions or learnings.

 

[Mike-M]

If you swap a different tranny and/or tcase in, it will almost definitely change your driveline lengths. Its pretty rare for 2 different trannys to be the same length.
You will probably have to move the crossmember back or forward an inch or 3, thats as easy as drilling some new holes. Then one driveshaft will need to be shortened (easy) and one will need to be lengthened (not easy, take it to a driveshaft shop).


Also, I dont know what bell pattern the 300-6 has but see if you can bolt any of the ZF5 variations to it. Its so much more highway friendly than the 4 speeds.

 

[Heffalump]

The ZF5 is a fine box, but this is going to be a dog by design. This is my son's 16th birthday present. It will not be a screamer, though it will be a fine woods-truck. I want the granny-gear, and the marginally unhappy highway performance.

I believe the bell for the 300-6 is the same as the 302 and 351. I'm guessing I'll have to go with a 2wd trans, a dee-vorced case, and some new drivelines. I'd imagine the entire setup off an F250 4spd would almost bolt right in.

 

[matt167]

the 300 i6 has the sbf bell pattern.. The T-18 in fords was either 2wd or 4x4. They did not use a divorced transfer at least in the '80-'86 years that I'm aware of. The T-18 2wd also had a slip yoke version and a bolt on version. I think you need a non slip yoke version if you want to do a divorced Case.

F-150s came with the T-18 pretty commonly till 1988, which was the first year of the M5OD iirc. They were available until 1992 tho

 

[Heffalump]

I was reading that the T18 2wd was a trapezoid bolt pattern for the output where the 4wd was rectangular. This is supposedly the sticky-wicket of this otherwise straight-forward trans swap.

The more I read, the more I think that I should just go with a divorced T-case.....and twin-stick it!

 

[matt167]

I think that the bolt on yoke 2wd trans can be converted with the 4x4 tailshaft, but the extended tailshaft slip yoke 2wd trans is different since the output shaft is longer. I have a slip yoke trans for my hotrod and I seem to remember the square or rectangle tail shaft mounting

 

[fordf150]

Easy way. Find whatever trans you want and the proper adapter to go from that trans to your t case. Iirc all the Ford trans output shafts have the same spline count. Divorced tcase is going to be hard to come by. They quit using them in early 70's. They would also be the np205. Strength wise they are better but they also only have a 2:1 low range. Newer aluminum case in either Borg Warner or new process has around a 2.6:1 low range. Done plenty of these swaps back in the day. Easier to just find a donor truck with the correct parts and just swap away. Lots of little things you will need. Clutch linkage, floor plate with shifter boot, cross member, trans mount, flywheel, driveshaft...and as has already been mentioned some t cases came with slip yokes and some came with a flange depending on gvw/wheelbase/engine. Every one I have done was a bolt in deal with no extra mods including an 81 f250 that started life with a 302/c4/new process and ended with me swapping in a 351 Cleveland/np435/bw1356. After I sold it the new owner swapped to a 460/c6 and kept the Borg Warner case.

 

[Heffalump]

Got my hands on a T18 set up for a married case for $100. The 208 should bolt up without issue. I'll be keeping it mechanical for now, but I'll definitely be replacing the seals on the T18 before installation.

 

[olyman]

Got my hands on a T18 set up for a married case for $100. The 208 should bolt up without issue. I'll be keeping it mechanical for now, but I'll definitely be replacing the seals on the T18 before installation.

and the seal on the front of the transfer case, also....don't aksk!!!!