Hi all,

we have a 48 F5 that we restored to original for a parade truck for our business. It has the original crashbox 4 speed that we would like to swap out for a synchronized 4 speed. Can anyone tell me what tranny would fit, and how to id it?

Thanks,
Colby.

 

With a little work you should be able to use a synchronized tranny from a '51 and up Ford transmission. I'm no expert on trannies but I do know the newer ones are slightly longer, about an inch. You'd have to modify the frame mount, maybe just move it back and shorten the drive shaft. Again, I'm no expert but I think if all you want to do is get rid of the crashbox the newer tranny swap would be the easiest. You wouldn't have to do any mods to connect it to your stock engine.

 

Bob is right, look for one in a 51 and 52 F-6 truck with a v8 and or the big six 254 engines.
your current 4 speed should have casting numbers on the drivers side of case (T 59 ) if I remember right and the synchro trans will have (T-98) cast in. I can't remember if the t-98 is slightly longer than the crashbox trans?? if so you may have to shorten the driveline.


Also a t-98 will have reverse pattern over and up while your current trans shift pattern for reverse is over and down.

I'm trying to remember what the biggest differences are from the T-98 trans from 1953 and up?? Try a couple Google searches on that subject with "FTE" in it.

Good luck

Josh

 

I'm going to bring my wife in here to see this!!

 

And she'll tell you Josh is wrong!

 

They don't have a provision for the transmission mount. The early trans mounts on the crossmember. The later trans floats off the back of the bellhousing, which was mounted to the frame supporting the rear of the powerplant.

 

My advice would be to just spend a few days with the crash box - it isn't that difficult. (I have the crash box in my F5 and the T98 in my F6).

 

What he said. Unless your crash box is trash, learn to shift it, it's bullet proof.
And like mentioned above, the rear mounts for a T98 would have to be fabricated. By the time you do that you would be just as well served to look at installing an OD transmission and make the truck more modern road friendly.

 

The transmission you want is the synchromesh 4 speed that Ford came out with for the 1950 model year. It was standard in all F-6's when ordered with the new 254 6 cylinder engine, and optional in all other F-4/6's. It is a direct bolt in swap for any 1948-52 F-2/6. You just have to shorten the driveshaft, because it is a little longer. The common, 1953 and later version is useless, because it has a completely different case, and will not work.
Chuck

 

Thank you all for the info. The trouble with the crashbox is that several different people drive the truck in various events, and not everyone can (or wants to) master the art of double clutching.

Chuck - is the 1950 synchro tranny the T98?

 

I'm not Chuck, but yes. However, word of warning, you can only use a first generation T98 out of a 50-52 Ford as they come with the correct back rear mount. In 53, the T98 case was redesigned and no longer had those mounts. Another difference with the first generation is the shift stick. All the internals are the same between the first and later models.

 

Did that a long time ago, F6 crash box replaced with one from a 1951
F5 one hour to change. Hardest part was taking the floor mat out.
Direct replacement I can prove it cause I still have the donar 51-F5 out
back, as well as the F6.

 

Yes, it's a T-98, but so are the later ones. The internal parts, with the exception of the input shaft, are the same through 1955. After that, they reversed the pitch of the gears. Also, although Ford says the later main shaft will interchange, I know from experience that it will not!
Chuck

 

Hey Chuck

don't you have a couple T-98 transmissions rebuilt and ready to go??

 

I never have the time to rebuild anything ahead of time anymore! I'm actually rebuilding one for a customer this week, and it's my last one. They have gotten pretty hard to find.
Chuck