Everyone knows that you can put sideshifter ford gears into a 39 Ford and later truck toploader transmissions, ie the ones that the part # begins with 78. But I was looking at some earlier cases (part #'s begining with 18 and 48) and comparing them to the 78 cases the other day and couldn't see any differnces other than the 78 cases being a little thicker on some areas. Is there any reason why some one couldn't put sideshifter syncro gears into one of these earlier cases? Jimmy
Even if you can fit all the later gears into the early case, you still need to find a '39 on up shifter/tower to use with those good synchros. So, is makes sense to use the later (and slightly stronger) case as well. If starting with a miscellaneous pile of parts, it doesn't really matter then.
Almost anything can be done with almost any case...clearance issues in '32-4 trans at cluster (and with big clutches) can be finessed pretty easily. Here is a rant on ID of types and basic interchange. Usual formula that most follow is a late set from a '40-48 trans dumped into any early case available, leving the good shifter fork the only hard part to get. What's what 101: http://www.jalopyjournal.com/forum/showthread.php?t=91515&highlight=1939+trans&showall=1
Curious, where they the later style (better snychro) or earlier style '39 gears? For I always thought the later style would crowd the bottom of the case too much. Glad to hear it worked out.
Because the "traditional nazis" say it must be so? I've got one in my 35 and 2 others sitting on the shop floor and I still don't understand. Must be peer pressure.
Could be also because they are so damn easy to work on. In about 15 minutes you have all of the guts out, ready for a transplant if you puked the first set. That is nice bonus to be able to do a lot of the work on these parts yourself IMHO.
I think the answer to the question of "why" is that back in the day it was considered to be the latest and greatest that wasn't column shift, and column shift wasn't cool.
Not everyone on here can rebuild a 39 themselves.... And column shift was harder to set up the linkage properly if you were building a Model A or 32 from scratch. There were some show rods and higher tech built rods in the 50s running column shift.
On clearance....in earliest cases. problem is at front cog on the cluster. On some there is not enough room for the gear to fit, requiring some minor grinding in front pocket area with a ball cutter on your porting grinder. Very minor. On many, gear fits nicely in running position but cannot be dropped far enough for the normal assembly procedure. In these, you just assemble everything but the input gear, then put in that gear and assemble its bearing and all the small bits in situ. No big deal at all. Early cases (see article linked) with the full taper up front don't clear clutches bigger than the 9"...later added a straight area in casting and very slightly dropped the cross shaft. I have never messed with these, but have been told that only minor grinding on the bosses holding the cross shaft is needed to fit a 10" clutch.
I love early Ford boxes and I never cease to be amazed at what somebody who thinks they can "rebuild" one can screw up! Even though a lot of the parts are interchangable they have to be used with the correct supporting parts, in particular, thrust washer sets, synchros and early/late gearsets.
Believe me, I learned that one the hard way. Now what I do is when I take the gears from a later side shift case is to use zip ties to keep everything together as it came out of the box. This way I don't have the problem of it not going back together the right way. You are right that if you start with a pile of parts, a lot of mix and matching can be done incorrectly.
Yes...if everything is from one donor trans, it is simple. If you gather gears from all over, you quickly learn there are about three variations of everything (AND some Canadian bits that are unique, too!*). Traditional need is the huge chart and set of dimensional pictures in the parts book. Van Pelt's book is probably best compact modern source of figuring out what's what. Your best bet for sanity is to buy a decent complete late trans and go from there. *I had a looooong exchange of messages with a Canadian Hamber with a thrust washer that could not be matched...I finally found a picture of it in an old Canadian catalog. Don't remember how he finally found a replacement.
"Back in the day" That is true. But once you had one you could use the later syncros and gears from a column shift for rebuilds. In the 50's you could go to any wrecking yard and come up with a 39 tranny. But even then the chances of it still having a top cover left on it was mighty slim. Column shift boxes were every where . The easy availibility of those parts and a general lack of knowledge on interchangeabilty and assembly led to many many destroyed Ford floor shifters.
Another amazing thing is transmissions apparently assembled and driven with utterly incompatible parts...a couple years ago someone showed me a '32 trans that was converted to open drive with truck rear parts. It still had a '32 shifter top on it... I did not have time for a look inside, but I guess it probably had a bent and ground '32 fork in there. That or amazing space edge craftsmanship with a lot of clever fabrication of detents and forkage...yeah, right.
The "39" tower (part number 91A-7230) was used in 39 cars...but also in pickups up to the late 40's-early 50's that ran the light duty three speed, floor shift. You could also get a column shift or a heavy duty three speed in the same pickups. For what it's worth I put a 1937ish tranny in my coupe. It has the strait up & down tower, but is a single detent. I took it apart, cleaned everything and put it back together. It is the BEST shifting tranny I have ever owned. I don't think you could grind a gear if you tried
I've been contemplating the possibility of cutting off the front fork on a slant tower shifter, and TIG-ing a newer 3" shift fork (like out of a side shift box...) where the old fork used to be, taking into account the shift of position of the 3" fork. Why is this so impossible?
It's not...I've seen forks BRAZED into place before!!!! You can also cheap out and grind the insides of the forks, making the gap a little wider. I belive the early forks were right at 3", and the later ones went to 3 1/4" or something like that.
Really, that I did not know. I could have swore I have seen an early tower modified to take later gears...can you heat/bend the fork to work?? Or maybe I was seeing things again
Don't know, just repeating what I was told. Sounded reliable enough (was it Bruce Lancaster who said it?) that I took it at gospel and vowed to never try it myself.
I was thinking that it can't be impossible if the later gears can fit in the early cases. I found this early slant tower shifter with a cool aftermarket "security" device that I would like to run on my 39 box in my roadster. I may just run 38 style gears in the box and go with it like it is though.
yeah. The 2 3/4" sliding ring has the groove centered on the ring the 3: ring has the groove offset. I think to compensate for the longer throw needed with the wider synchros.
Does that thing lock? Looks cool as hell! I'd go with the earlier gears. Like I said I have em in my coupe, shifts excellent.
Yeah. it's an aftermarket locking shift tower. meant to prevent any joy riding someone might do on your 32-34 Ford!
The original Q was "Why a 39." So I went to a guy that was there in the day. Grew up in East LA street racing in the 50's. Here's what he said; "The 39 and later boxes were fairly easy and cheap to find used and they didn't require any grinding, modifying or other work to use them. You could put the later synchros in, Zephyr gears, or whatever you wanted and they were easy to do. As Hot Rodders in the 50's we weren't looking to be innovative or different with modifying old stuff, we wanted to use what would work best with the least amount of trouble. The 39 case was also a little stronger, although we still grenaded quite a few of them with a Hot 3/8 X 3/8 Flat motor." So there is one mans opinion from a guy who was there. He's 78 years old now and tells it like it was, or at least as he remembers it.
More complex than that even. Differences include placement, size, and travel on '32-5 shifters. You'd need to build new rails and detent positions at least. I think travel is same on 1936--39 early type as on late type, so only size and placement of fork need change. Gear set used '36-39 is nearly the same as the late setup except at actual synchro and synchro teeth on gears. '32-35 types are different in many ways. Two late tops are 68 type (1936--37) and 81A type used from 1938 on, available with both sizes of fork. The 81 replaced the 68 as the service part. I believe the '36-7 works fine with late fork, but have never tried it myself.
The Jalopy Journal
