75 Ford F-250 Transmission Choice?

[JPihl]

Hey all -



1st post for a TDR noobie here! I've spent a bit of time here looking and learning in preparation for my 12V transplant and haven't found a definite answer for how to set up my driveline. F-250's up to 1977. 5 have a divorced transfer case (either a NP203 or NP205) with a shaft ~12" long connecting to the transmission. I am debating the following:



1. Using a 2wd 47RH transmission and leaving my NP205 where it's at, and reducing the length of the short shaft between the t-case and trans.



2. Using a 4wd 47RH transmission and Dodge transfer case, and having front and rear driveshafts lengthened/shortened.



I am leaning in favor of option 1. Theoretically, the divorced t-case should make it pretty easy to put pretty near anything in front of it, but I am not sure what driveability, strength or install issues I am overlooking.



Thanks,



Jeff

 

[stacerbob]

There is nothing wrong with the "Highboy" divorced 205 case. I wouldn't keep it if was a 203 Full time. If you are building off road etc... you "could" use an Allison also. Good Luck I have a '76 with a '70 body that I want to drop a cummins in someday. Be sure to take pics!

 

[GLockwood]

Hi JPihl ,

I am using a dodge transfer (i plan to anyway ) . The 205 is supposed to be very strong . My f250 came with a 300ci 6cyl and the driveshafts look too small . I don't know if the V8 ones are bigger , but you may have to upgrade them ? Perhaps someone else will know about this (stacerbob?) ?

Shortening the transfer shaft should be OK if the shaft and uni's are fairly straight (lined up) . I have been told they work best with 5* of angle on the uni's as the wear out if the rollers don't roll at all (ie if the uni's are perfectly straight) . :--)

I probably won't be much help as I'm in Australia and have very limited access to Dodge trucks etc. ,

Good luck ,

Graham.

 

[DieselTweaker]

sounds like your working with a high boy,,, is the front end a ball and socket ??? any pic's of the t-case?

 

[Speedo]

The front axle is a driver's drop, D44 and is not very strong. If you plan on running a 205 you'll need to use the Ford 205 as the 205s that Dodge used were for pass drop front axles. In '94 when Dodge changed body styles they went to a driver's drop front axle but they went away from the 205 t-case.



Gus

 

[JPihl]

partsman - My Ferd is a Crew Cab with the 360/NP435 & NP205. It's got Dana 60's front and rear, but the front 60 is old school with closed knuckles and big drum brakes. I understand this axle is plenty strong, but obviously it'd be nice to upgrade to a 60 w/ discs at some point - the Cummins conversion comes first, though! No pics yet... .



Jeff

 

[Scot]

I did a '75 F250 4x4 6. 9/T19 back 10+ years ago.



I would run the t/c as is. Dome of those trucks got a C6 and that should be about the same length. Build new driveshafts using 1410 joints and yokes. You will hammer out u-joints almost instantly if you try and run stock stuff. I was getting 5K miles out of Spicer joints behind a strong 390 and the 6. 9 that I replaced it with.

 

[JPihl]

Scot -



Thanks for the advice on the driveshafts. I've been admiring your conversion pics both here on TDR and FTE. Your pics and contributions on the forums has given me confidence that I can pull off my own Cummins conversion. I've decided to keep my divorced Ford NP205 and put a 47RH in front of it.



partsman - I've posted a few pics of the D60 and the t-case in my gallery.



Jeff