I built a 1930 Ford roadster hot rod, using a 1953 truck motor, clutch assembly and transmission out of a 1953 Ford PU. I suspect it came out of a 1953 F-250, because its a floor shift 3 speed with the emergency brake as part of the transmission. Generally a 3 speed transmission in 3rd gear has a 1:1 output. Do you think this transmission is a 1:1?


1st gear does not seem to have synchromesh. I have a 1950 Ford sedan 370 differential and was hoping to be able to cruise at 60 mph. At 60, it seems to be running pretty fast. My tachometer may be wrong.


Thanks in advance
John L.

 

The original 3 speed transmissions in all of these trucks were a 1:1 ratio in high gear. First gear was not synchronized. Only second and third.

 

I would look into some 3:25 gears...

 

Wayne is correct, and Charlie has a good suggestion. Given that this is a light roadster, you could put some pretty steep gears in the rear to achieve lower engine revs. at 60, and yet still have good acceleration at low speeds.

 

Thanks for the information, I posted a picture in my avatar, the car weighs less than 2000 lbs, so my first gear is worthless. I've been using 2nd gear for startups. I've already added an Edelbrock 4 barrel and have a bubbas distributor on order, so I should have good power.

 

Good Idea, I need some tall gears, will probably have to get some made. I've been told 3:70 is the tallest gear made for the 1950 ford rear end. I would hate to redo everything to get taller gears.

 

How about swapping in an OD trans like a T-5? Yes it would be a bunch of work, but man they are nice behind a flat motor.....

 

4209 Ring & Pinion, no see um 3.70-1.

 

It would be nice. I have the emergency brake connected to the back of the transmission. I would be a job now.

 

It looks like it is critical that you discover exactly which year and model rear axle you actually have in the car. There were design changes between 49-52 with the 50 being in many ways an intermediate (ne orphan) design. Since Bill's chart does not show a 3.70 R&P being offered by Ford in the era, it would also be good to determine the actual ratio in your car before proceding.

 

Nice chart, thanks for the information. Now I have been exposed as to how little I know. Looking down the list, there appears to be a 3.30 to 1 That has a 33 ring and 10 pinion. If I could find one that would be perfect. I have other issues to deal with now and it may be a couple of months before I can get to it The best I can tell my tachometer is sitting at 2500 at 40mph.


Would you know a company that might could provide a set of gears?

 

I agree. I pulled the rear out of a 1950 ford overdrive sedan in Alamogordo, NM. It appeared to be an original rear. After it was installed, I was told the OD transmission used a 4.10 ratio, so I contacted a friend in Florida and a acquired a ring and pinion set out of a 1951 ford sedan with automatic transmission and was told it was a 3.70. The 4.10 and 3.70 numbers appears no where on Bill's list The second set of gears are much taller, but still lower than I would like. I live in the mountains and with the current gearing I have no problem going over the mountains.
The motor and transmission came out of a 1953 Ford truck. I did not see the truck, but the motor is an 8BA. The transmission has an attached emergency brake that operates a brake band around the drive shaft. Not the best transmission set up, but looks super cool in a hot rod.
The car runs just fine the way it is, just does not have much top end. Maybe 50 or 55 MPH unless you want to wind the engine up.

 

Would need the tire diameter (for accuracy measure from ground to center of axle multiply x 2 to get the corrected rolling diameter) to calculate the gear ratio from RPM and speed. Bill (numberdummy) is plugged into the NOS dealer network can tell you if a NOS gear set is available and where.

 

AX, the tire diameter is 12.5 inches from the floor to halfway of the axle. Tire size is 205-70 R15. from the floor to the top of the tire is 26 inches.


I suppose the rolling diameter is 25 inches.


The best I could read the tachometer at 30 MPH 1800 rpm, 40 MPH 2200 rpm, 50MPH was a little over 2600 rpm. Hard to read a tach going up hill or down hill, not much flat here.

 

Just a suggestion, but if you went to a taller rear tire, say 28-29 inches it would lower your rpms considerably.