Shifter fork wear

[HDowse]

Here's another question that's come up as I rebuild my early '39 transmission. I disassembled the shifter, removed the forks and checked the wear on the the 2nd/high fork. My question is how much wear is OK? The fork tips measure .303 and aside from a slight ridge the surfaces are smooth. Does this look serviceable?

 

[alanwoodieman]

well worn and the syncro outer gear must be worn also--too much play for it to be good. but did I read this correct part #68-7230 this is not a 39 trans this part should begin with 91-for it to be 1939

 

[HDowse]

Alanwoodieman, the previous owner said he thought this replacement transmission for his 37 pickup was a 39 but you’re right most of the parts spec out as 68-. When you say synchro outer gear, what gear is that? I’ve got to order some parts from Mac VP and I'll get a new 2nd/3rd fork.
Sometimes I think I’d be better off going with the newer synchro, main shaft and gear set.
Hunt

 

[Tim Ayers]

Alanwoodieman, the previous owner said he thought this replacement transmission for his 37 pickup was a 39 but you’re right most of the parts spec out as 68-. When you say synchro outer gear, what gear is that? I’ve got to order some parts from Mac VP and I'll get a new 2nd/3rd fork.
Sometimes I think I’d be better off going with the newer synchro, main shaft and gear set.
Hunt

Best way to do that is find a gently used side shift box and use all the gears, synchros, etc from that.

You’ll need a top with the bigger forks, but they are around too.

 

[alanwoodieman]

I restored a one family owned 36 Ford and used the original syncro, this car has been on the road for a lot of years with no problems. you can also use a reproduced syncro fork and put in the 39 syncro

 

[HDowse]

Good to hear that about your 36 restoration working out successfully. All of the gears in my transmission are in excellent shape so I'm planning on keeping the original synchro with new springs and balls from Mac VP along with all new bearings, thrust washers and bushings plus a new reverse idler shaft. It worked back in the day so it ought to be OK once the new parts are fitted. It's been good learning about this style of transmission. My only other repair was a 46 GMC with the newer style brass synchro wear rings. But getting parts was a bear and very expensive.

 

[TerryOH]

If you check the vehicle serial number stamped above the clutch inspection cover it should tell you if the case is 39. I believe some of the early 39 had the slightly earlier gear set. I cant tell if the wear is on the face of the fork or the inside. If on the face toward 2nd or 3rd I would replace the fork. Note the slight arc pattern of the wear.

 

[HDowse]

Terry,
You’re right about the fork having that wear pattern. I ordered a NOS fork from Mac Van Pelt this morning. The motor in the truck shows a serial number in the mid 39s but it’s a replacement for the original 37 motor. Before that switch was made, the transmission was picked up from a junk yard, probably in the early 50s, and was changed case and all, fitted to the original motor. So there have been a lot of substitutions. With the new 2nd/3rd fork, new thrust washers and new bearings, it should be within specs for an early 39 transmission.