Overdrive transmissions
 

Hey guys, I’ve got a 1950 custom deluxe with the 3 speed with OD, it’s worn out and today it got jammed in second gear(seems to be internal), anyway there’s a guy who’s selling a rebuilt overdrive trans out of a newer car or truck(a 58 or 68), are newer transmissions compatible with flatheads? Or do I need a 49-53 transmission? I have pictures of the stampings on it

Re: Overdrive transmissions
 

You will need a transmission with the boss on the shift cover to attach the clutch actuator. They are '49-'51 specific. One of the casting numbers indicates a '68 (C8A). Ford changed bolt patterns on the transmission about '64.

Re: Overdrive transmissions
 

The only transmissions that will fit without modifications are '49-'50. The '51 looks a lot like them and has the clutch boss, but the mount has been relocated further forward, so it's not a bolt in. It could probably be adapted by changing the transmission mount. The later transmissions don't have the clutch boss, and as mentioned above, after '64 the bolt pattern is different.

Re: Overdrive transmissions
 

I’ve read where the trans mount can be turned backwards and the ‘51 trans can be used in a ‘50 or possibly vice versa. There’s also something with the solenoid but that might be with the convertible frame.......Mark

Re: Overdrive transmissions
 

Ok that helps a lot, is there a good place to get parts for these transmissions? Last I checked on shoebox they only had seals and the overdrive electronics
And on a side note, do you guys know if the internals are the same? If so I could potentially swap all the guts from the rebuilt 68 trans and put them in my case?

Re: Overdrive transmissions
 

Van Pelt Sales is a good place to find transmission parts. There are other sources that I am sure will be recommended by the members here. As to swapping gears, I don't think that will fly. A change in the gears was made mid-year 1951, so I don't think anything later will work. By 1968 the transmissions had changed enough so that I don't think anything will interchange.

Re: Overdrive transmissions
 

Take the side cover off and look inside might be jammed against the syncro just watch how the shifting forks are located ps. Vanpelts are the best just dealt with mac a couple week ago great guy will talk you through any problem

Re: Overdrive transmissions
 

Ok, hopefully iil be able to get to it Saturday, another question I have is can you put the overdrive unit on a non overdrive transmission? From what I’ve seen the front halfs of the overdrive and non overdrive transmissions look identical

Re: Overdrive transmissions
 

On my stock 49 woodie, I used the stock 3 speed trans and a 49 overdrive trans, combined the good parts, purchased new gearsets, bearings, tailshaft bushing, seals, etc., to build one good transmission. Several thousand miles later, and all good. My stock 49 had broken teeth, big mess inside. Got a few parts from Van Pelt. They know their stuff. Rebuild what you have. Check that tailshaft bushing, they wear and can cause driveshaft vibration. Might want to check your driveshaft U joints for wear. I did not and had a U joint break on Highway 49 in the California Sierras.

Re: Overdrive transmissions
 

Did you put the overdrive unit on the regular one?

Re: Overdrive transmissions
 

That C is for "Made in Canada". That case would work as long as the original side cover will fit on it for the clutch works.

Re: Overdrive transmissions
 

The mounts are different though aren’t they? And what about the bolt pattern to mate to the bell housing?

Re: Overdrive transmissions
 

This will probably work fine if you use the right combination of parts from the respective transmissions (gears from the non-overdrive transmission will probably go right in). There are some problems with differences in the cases with provisions for the reverse lockout, so there might be problems depending on what you swap out.

Re: Overdrive transmissions
 

The problem probably lies in your min transmission. You will have to disassemble the whole transmission to replace any parts but they are readily available. These are not overly complicated to do but require some skills. If you do not have a shop manual get one and follow the instructions, I think the overdrive unit is covered in the accesories section and not in the transmission section.

Re: Overdrive transmissions
 

Ended up using the OD transmission complete, after rebuilding. Used parts from the original, although not many. The case, shift levers, were in better condition. Power Block TV, years ago, did a rebuild of this trans.

Re: Overdrive transmissions
 

Ok Thanks, makes sense
Has anyone come across bent shift forks with these transmissions?

Re: Overdrive transmissions
 

In 1951, the new diamond tooth gears showed up. If this is a later unit then it likely has those gears. The tail shaft & housing may differ depending on the year of manufacture. The later 259 series transmissions also had their own differences but I don't know if that unit is that late. I'd guess pre 1954 but after 1951 but it could be earlier. I can't really tell with the photos. They should all have the 1-inch 10-spline input but they have different gear teeth than the 49 thru 50 and early 1951. The front bolt up pattern is the same narrow 4-bolt Borg Warner pattern that was used a lot during the late 40s clear up the the early 60s. The early T-10 4-speed even has that pattern.

The forks don't bent easy but they can get that way during an internal failure or under harsh use.

Re: Overdrive transmissions
 

Easier to fix yours,usually when they stick in second gear the syncro sleeve has traveled to far due to excessive endplay and the detents for the blocker rings have popped out behind the sleeve so it can't return to neutral.
Bill

Re: Overdrive transmissions
 

So if I can swap the side cover From the 50 trans to this newer transmission It should work? It looks like rear mount is in the same place and if the bolt pattern for the bell housing is the same

Re: Overdrive transmissions
 

Here’s my transmission