o/d 3 speed vs. 3 speed

dougson

What's the difference between the regular 3 speed Hudson manual and the overdrive version? Are they the same except one has an overdrive mechanism installed or are they structurally different transmissions?

Jon B

The overdrive (or fourth gear, usually with a ratio of about .7 to 1) is in a separate mechanism behind the 3-speed gearbox. So the whole overdrive transmission is longer than a 3-speed.

[Deleted User]

Its the same tranny with the OD unit bolted on instead of the normal tailpiece.

dougson

51hornetA wrote:

Its the same tranny with the OD unit bolted on instead of the normal tailpiece.

Thanks! Now, as I should have asked before, can you still find o/d units? I have a '54 3 sp without the o/d.

[Deleted User]

dougson wrote:

Thanks! Now, as I should have asked before, can you still find o/d units? I have a '54 3 sp without the o/d.

Running it with an O/D will be a night and day difference for the better.

Jon B

Sure, they're available. Check the WTN classifieds, also you might contact Al Saffrahn, who is an expert on Hudson OD's

Unknown

You have to have the over drive trans. Cant just bolt the overdrive unit to the standard three speed.

[Deleted User]

Billy K.TN. wrote:

You have to have the over drive trans. Cant just bolt the overdrive unit to the standard three speed.

Billy is right and you also have to consider that there are internal parts to an OD tranny that will only work on an OD tranny. 3 speed trannys won't supply the parts. It's really like a seperate type of manual transmission thats semi electric.

[Deleted User]

The electric parts are in the OD unit with is in the tailpiece. Since he has a 54 3 spd that is a R type tranny which you can add OD to. Even the W type trannies can add OD. Looking at the manual and the Hudson parts book gives you the parts you need to change out. You need to mod the shifter forks for the OD lockout but thats not a big deal. A little work you will have OD. Or find a complete tranny and OD. But if you have the parts you can do it. Got one I built on my bench now.

LanceB

I have a '52 308 with the single lever three speed, which I believe is the original trans in my '46 truck. To keep the single lever collum shift what would I need to get for an OD setup?

LanceB

Thanks for all of this Rick, and good luck with your project.

super651

Rick, Thanks for the info on your web-site about installing a Overdrive in the 1946-47. Mine is a 3-speed and I will install an O.D. trans later in the year. Rudy

dougson

Lot's of good info, thanks for input. It turns out the trans. I have is a '49 single lever. So from what I am reading above it is possible to modify it and add an o/d unit, right? I realize that a shorter driveshaft is required and a support/cross member may be necessary.

Unknown

Guess I may not know what I am talking about but on the rebuild of my 47 pickup which has the correct engine I put a 51 trans with overdrive in. The 51 bolted to the 47 bell houseing. Lance on your truck I think all you would need is the complete OD trans with switches, control cable etc.have to use shorter drive shaft. I fit a stepdown shaft to mine. With this trans you have to pull engine to get it out. I also changed the 456 rear to 411. I t all sure made a difference in driveing.

[Deleted User]

The best info I found was the Jeep forums. Those guys are modifying everything under the sun. I have 4 3spds I have be working on. Got most of my mod info over there. Everything from wiring harnesses to install and mod of the guts of the tranny. The T86 was a popular tranny installed in lots of cars and trucks. So yes tons of mod info out there. You have a bit of work to do to make it happen its not a bolt in you have to mod stuff.



Of course if you can find a complete OD tranny go for it but if you like me buy four trannies for $50 you play around with them. Best way to learn.

SuperDave

dougson wrote:

Lot's of good info, thanks for input. It turns out the trans. I have is a '49 single lever. So from what I am reading above it is possible to modify it and add an o/d unit, right? I realize that a shorter driveshaft is required and a support/cross member may be necessary.

When you say "modify it"I'm not sure I understand. To make sure we understand each other,You cannot modify the single lever 3 spd transmission to make it an OD. You can swap it for a single lever OD transmission. If the 49 3 sp transmission is installed in your car, you can install the OD transmission with only a drive shaft swap. The transmission mount for both transmissions are the same. The wireing is complicated for the 48-51. Much more simple for the later (2 lever) versions and by using the later solenoid and wireing you can do the job very easily. It's not rocket science, but can be confusing. I have a good single lever OD (49) transmission I could sell you. PM me if you are interested. My email is HETdwad1939@att.net.. omit the HET..:D

Sarah Young

Overdrive provides a driving ratio of engine speed to rear wheel speed that is numerically lower than direct drive. In overdrive, the engine revolves 30% slower than in direct gear at the same car speed, resulting in less wear on engine parts as well as greater fuel and oil economy and smoother operation at high speeds.