39 Transmission experts

J

Jonnyenglish

Member
I have searched and found a lot of information from very knowledgeable people, it seems you cant really determine what trans you have by the number on the case as different internls can be fitted to different cases. The internals on the photo below have some differnces to photos ive seen posted on here, so does anyone know what i have (i realise i may have to do some counting). Thankyou.
IMG_5665_zpsmd9p97nd.jpg
 
Jonny, I don't consider myself to be an "expert" on these transmissions, but from the experience I do have from working on '33 to '48, 3 speed early Ford V-8 transmissions, your gears as pictured appear to me to be in the range of '36 to early '39, prior to the later type improved synchronizer gears used in later '39 to '48 transmissions.
 
You've realized an anomaly about Henry's transmissions. It seems to me he continued to offer the '36 - '38 type into the early '40s in the Commercial line as well as using up 68A single detent shift tops on the pickup transmission into the mid forties. It does look like you have a '36 to '38 type transmission. Is it a single or double detent top? Paul J.
 
FoMoCo had a practice of "using up" parts from earlier designs. This practice did not last for years because it is too confusing for assembly line practices. I doubt if it would have lasted much more than 6 months from date of change. It's just easier to make one type assembly than it is two. Henry Ford was pragmatic to say the least. During the war, a person used whatever they could find to keep their vehicles going so a lot of old to new and newer to older parts were swapped when necessary. Its not uncommon to find older engines & transmissions in newer vehicles.

Mac's book answers all questions that I could ever think to ask. Loads of pictures to identify all the different parts and what parts work with each other too. He sells the best quality parts that are available as well.

If that's a 37 or later case, you can get gears from a side shifter or top shifter transmission to convert it to the 39 & later type synchronizer set up. You also need the shift fork for that synchro in the tower. I think Mac has repros of those forks available now so you don't have to search as far.
 
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Thanks for your replies.

It is double detent.
When i took the photo i have to admit i didnt really look at the condition of it all, but looking at the photo i have put a red circle below, i assume that isnt right, is it chipped/worn?? - You may gather i know nothing about these!
EDIT....just looked on the excellent link to vanpelt and they are not chips or defects and it does indeed look to be 36 - 39.
Thanks all.

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It definitely has the early synchronizer. Count the teeth on the main shaft and the cluster gear. Probably 28/16 gear combo for a 3:78 rear end.
 
It would be interesting to note the serial number that's stamped on top of the case bell housing, on the flat spot above the clutch inspection plate, and also the case part number that's cast into the back of the case. This would tell us what year case you have even though this might not be the original case that came off the assembly line on your car, and it's also possible that the gears could have been changed in that case in the last 70+ years of its existance as you mentioned in post #1. If you don't feel comfortable posting the complete serial number, just fill in the blanks on this ☆18- _ , _ _ _ , XXX ☆, if this is at all like the stamped serial numbers on your case.
 
The serial number on the case by the inspection plate, does not match the number on my frame, so the trans isnt original to the car, i guess?
The trans serial number is: *18-4895...
I couldnt see the other number on the case although i did look for it but not quite sure where it should be.
 
You should be able to find the case casting number on the back side, lower left area. You will probably have to go digging and cleaning to find it. It's probably 18-7006 ('32 through '34), 48-7006 ('35-'36) or 78-7006 ('37 through '50). Refer to Mac's "Trans Identification" section for explanations of the three types.
 
The 18-4,895,xxx should be in the 1939 serial number sequence. I'm no expert, and I used a 1950 Motor Manual for a reference on this.
The casting number is usually at the lower back of the case, and is generally unreadable if there is any crud on it. I think the guys are looking for a prefix, such as 48- (1935), 68- (1936), 78- (1937), 81- (1938), 91- (1939), 01- (1940), etc.
There is also the possibility of a 99- (1939 Merc), although I'm not sure if that even exists... just speculation.
 
bobH said:
The 18-4,895,xxx should be in the 1939 serial number sequence. I'm no expert, and I used a 1950 Motor Manual for a reference on this.
The casting number is usually at the lower back of the case, and is generally unreadable if there is any crud on it. I think the guys are looking for a prefix, such as 48- (1935), 68- (1936), 78- (1937), 81- (1938), 91- (1939), 01- (1940), etc.
There is also the possibility of a 99- (1939 Merc), although I'm not sure if that even exists... just speculation.
Click to expand...

That also agrees with the serial number info given on Mac VP's website for '39 85hp V-8's:
18-4,661,001 to 18-5,210,700. So early '39 was a good call.

The casting number on the back of the case is usually difficult to read, especially when its covered with years of built up and dried dirt and oil mix, and also partly covered by the rear transmission mount. But as Bob said, a two digit prefix number would tell the story, and now considering the serial number given, more than likely a 78-xxxx style case that began use by FoMoCo in '37, and saw use up into the '50's on Ford pu's.
 
Those prefixes are in the trans case number, not the serial. The gear set shown was originally used in some 48 cases and some 78 cases. Since essentially everything '32-48 can be swapped one way or another, you want to first identify year of trans from serial to see what it was originally, then examine gears, clutch lever, rear mount, etc. to see what was modified and what non-original vehicle it might have been used in...
I attempted a fleamarket guide to this a few years back:

http://www.jalopyjournal.com/forum/threads/39-ford-transmission-prices.91515/
 
Lots of excellent information here, and Bruce certainly seems to know his stuff. Thanks very much, il try and find the number on the back and report back.
 
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