Dick Listro: 4/9/2000 - 9:52:57 PM
49-51 Transmission Question
I broke the cluster gear in my '49 car OD, I pulled a cluster gear out of a 49-51 3 speed. I counted the teet and realize that they are different. I assume that I will have to change all the gears in the O/D with the gears form the 3 speed. Right? And will they swap out?

JWL: 4/9/2000 - 11:04:38 PM
RE: 49-51 Transmission Question
According to the reference material I looked at, the 49-50 models have different tooth counts than the 51 and up. I can't be certain about swapping everything, but my bet would be that they will.

rumble seat: 4/10/2000 - 8:33:40 PM
RE: 49-51 Transmission Question
Dick Listro:
The '49-'50 Ford ran a different trans than the '51 Ford. The '51 used tapered shaped teeth on their low-reverse (L/R) slider gear. The '49-'50 both used perpendicular cut teeth on their L/R slider. Their cluster gears are not interchangeable (look at the low gear difference on the cluster). The L/R slider gears are not interchangeable either since the '51 tail shaft uses a different gear taper where the L/R slider gear slides back and forth. Therefore you must use a '49-'50 tail shaft, cluster, reverse, and L/R slider..... OR us a '51 tail shaft, cluster, reverse, and L/R slider.

As to gears. In the '49-'50 trans you'll usually find 15/29 or 16/28 gears. (Both use the same second, reverse, and L/R slider along with identical synchro drum assemblies.) The smaller number denotes the number of teeth on the main drive gear (MDG) and the larger denotes the number of teeth on the large end of the cluster gear. The 15/29 was usually on a standard trans and the 16/28 was usually on the Overdrive. The 15/29 have ratios of 3.11:1 in first and 1.77:1 in second. The 16/28 have ratios of 2.82:1 in first and 1.60:1 in second. As you know, all of these trans had 1.00:1 in high gear (not in overdrive). As can be visualized, the 15/29 was quicker off the line, but had a good drop from second to high. This was because the standard equiped cars came with a lower numberical rear end ratio for the highway. The 16/28 was slower off the line, but was a closer ratio trans and had about even drops through the gears. The '51 trans were also 15/29 and 16/28 with the same ratios.

If you're going to put an Overdrive in a convertible or station wagon, these used a unique solenoid adapter for the solenoid. These are needed since the center of the frames on these two don't have room for a standard placed solenoid. These adapters are VERY, VERY scarce and expensive. You can cut the frame slightly and get enough room for a standard solenoid. I've been told you can use a '51 passenger car Overdrive in a '49-'50 convert and come up with enough clearance because the solenoid is mounted lower on a '51, but I've never tried it.

The fabled Lincoln gears? You must replace the MDG, the cluster, and the second gear. The L/R slider for a pre-'50 trans is correct as is reverse. The 18/26 Lincoln has a 2.33:1 first and a 1.58 second. The 19/25 has a 2.12:1 in first and a 1.44 in second.
Good luck... rumble seat

Return to Index Page