Is there any rhyme or reason to which non-overdrive 4 speed trucks ended up with? My 79 F350 2wd w/ a 400 has the the np 435 while my 79 F250 4wd w/ a 351 has the T-18. Is it a factor of engine size, 2wd vs. 4wd, 250 vs. 350? Also, is one more desirable than the other?

 

I think it goes by engine /GVWR / rear axle when they pump them out for dealerships.

But special order trucks can be practically anything.

 

My 78 F250 2wd w/400 has the the T-18. I think it was just supply and who got what shipment. The NP 435 is a few pounds lighter because of the aluminum top plate, probably wears faster tho...

 

In all honesty the difference between a np435 and a T18 is very minimal besides one having the aluminum top cover. Now if you want a T19 which has sync 1st and reverse just depends on what your gonna do with your truck.

 

I agree with Torque1st's comment that 4-speed transmission supply at the time may have dictated in large part what engines got certain transmissions.
I believe all the Ford-supplied 4-speed transmissions (except the ones with OD, like Clark, Orion, RUG and SROD) were rated for heavy duty service.
I found that the T19, with its all syncronized gears was available in F250 and F350 trucks with diesel and 460 gas engines. The T19 came with three gear ratios: close, standard and wide. The close ratio T19 (4.02:1 first gear) was available only on diesel engines, whereas the wide ratio T19 (6.32:1 first gear) was available only with the 460 engine in 4x4 configuration; the commonly found T19 with the standard ratio has a first gear of 5.11:1.
I recently rebuilt (fairly easily) and installed a T19 close ratio in my F100 truck with a 300ci engine and a 2.75 rear gear, and it has made it into a really practical daily driver in city traffic. Raul

 

The T-19 is a great upgrade if you can find one. They were also available in school buses and box trucks like delivery vans and bread trucks etc. I was intent on that upgrade from my T-18 until old age and damage to my knee and made clutch operation uncomfortable. I looked for a long time and did not find one.

According to a 1978 OEM manual the T-19 is a transmission code "P" as opposed to an "F" for a T-18, and "A" for a NP435. If you find a code "B" that is a Clark 4-speed overdrive. These codes were normally fairly constant over a few years of production but check anyway. There are oddballs and replacements have been made...

 

The T19 are becoming a bit more easy to find at junkyards nowadays as the mid-80's F250 and F350 trucks are arriving to these boneyards. At least that is what I have been observing in the big yards in the Dallas metro area. This past weekend I bought the shifter from a T19 equipped F250, and the trans actually looked very clean. I did not purchase the trans because it had the 5.11 ratio, and I already own one like that (a spare, that I am planning on rebuilding and most likely sell). I would, however, like to find me a wide ratio T19 (6.32 first) for a 4X4 project I have in mind. My project is kind of backwards, as I am concentrating first on drivetrain (built 300CID inline six, T19, transfer case) and then find me a suitable chassis and body (like a 73-79 short chassis or even a J**p Wrangler or truck).

 

You will need some of that fake mud for the Heep...

 

I suspected it might have been just a supply and demand situation but wasn't sure. I checked my 79 OEM Light Truck Shop Manual and the "P" code isn't even one of the choices. "F" is listed as "Warner" (T-18), "A" as "New Process" and "B" as "Clark OD". Was the T-19 even available in 79? If so, in what?

 

Dennis may have 79 info. I only have 77 & 78 info.

 

Mayme if was a case where that New Process or Borg Warner individually couldn't meet the production Ford required, so Ford sourced transmissions from both manufacturers. Maybe that is why there seems to be no rhyme or reason for what they were put in. Maybe it just depended on what was in the crate that week for transmissions. Just my .02.

Steve

 

Based on my research on the T19 transmissions, it was available mostly during the 1980's (around 1983 to 1989 or so) on "medium duty" trucks (F250 and F350); I do not know its availability in other applications. Its older sibling, the T18 (almost the same but with a first gear non-synchronized) was available since the mid-late 1960's until the early 80's. The 1973-1979 trucks never were factory-equipped with a T19. It is however, relatively easy to do the swap, particulalrly if you already have a 4-speed transmission and the correct bellhousing. My '78 truck w/300CID engine had a Clark 4-speed w/OD and it was a straight swap (except I had to move the trans crossmermber one inch and lengthen the driveshaft (the T18, T19 and NP435 have the shortest cases compared to most others, and all weigh around 150 lbs). Raul

Torque1st: There is a guy in the fordsix dot com site that has a J**p (I think a CJ) with a built Ford 300 with a T18, with an outstanding power (actually low speed torque) to weight ratio, crawling prowess, in addition to the reliability and simplicity of a carbureted 300 engine (legendary). I need such a vehicle for our little house in the pristine mountains of NE Mexico. I am a Ford guy, so my first choice will be a 4WD 1960-70's SWB F100/150, but I may even get me a regular cab F250/F350 and just chop the back of the chassis (after the rear wheels) and use a heavy duty flat bed.