The Ford Barn

Hunter · 10-13-2014, 10:43 AM

I am beginning to wonder if the gear cap assembly for 1928-1929, set up for the 3.54 to 1 rear end exists. At Hershey I looked at over 50 gear cap assemblies and never found one with this marking. Also called Steve at Bert's a few months back and he didn't recall ever seeing one.

Have any of you folks ever see a gear cap assembly with the 11-39 (per judging standards) marking?

Thanks in advance - Hunter

Ron in Quincy · 10-13-2014, 11:30 AM

Ford never produced a 11-39 speedometer drive gear when they came out with the 3.54 ring and pinion late in 1928; this gear ratio was only recommended for the roadster at that time. If you can find a speedometer drive gear marked 10-37 ,it was used on the 28's with a 3.70 rear end, it has 18 teeth on the drive gear. Also some of the dealers sell a 18 tooth drive gear and you can convert a later drive gear with 19 or 20 teeth, to the 18 teeth. This is as close as you can get for the 3.54 rear end.

Ron

Tom Wesenberg · 10-13-2014, 01:56 PM

If you add a gear with a tooth or two more, then you might have to add a gasket or two to the housing to space it a bit farther out from the driveshaft gear.

Hunter · 10-14-2014, 03:01 PM

Ron and Tom,

Thanks for taking the time to respond to my post. I'm still a little confused.

Ron thanks for sharing with me that this gear ratio (3.54) was only available for the roadster at that time. When the roadster was equipped with the 3.54 wouldn't it have had a gear cap assembly marked 11-39?

A little background - when I restored my 29 Coupe I installed the 3.54 gear. It originally was equipped with the standard gear. I noticed (using a GPS) that the speedometer was registering low mph which made sense since I did not change the speedometer gear (19 tooth to 17 tooth). I spoke to two well respected vendors. One indicated that I could simply replace the 19 tooth gear with a 17 tooth gear and all would be well. The second told me that if I did that it would chew up the speedometer gear and I needed the right casing to make it all work. I took the easier path and simply replaced the 19 tooth with a 17 tooth leaving everything else the same (gear casing/gaskets). Well it registered very close to correct but after 50 miles the speedometer stopped working. I removed the gear casing and found that the 17 tooth gear was completely chewed up.

So is it the case that the 10-37 gear case being the right one for the 3.70 gear (per Ron's response) that one can use a 17 tooth gear or do you have to stay with the 18 tooth gear. Do extra gaskets help eliminate the "gear chewing"?

Finally, what is the difference in the actual gear casings? Is the shaft aligned differently? Is the shaft recessed to a different depth in the casing?

Thanks in advance - Hunter

Ron in Quincy · 10-14-2014, 04:33 PM

The difference is the speedometer cable housings; the early housings had a keyway, the later housings had a square connection. The early speedometer cable has a keyway on the housing end and square on the other end to engage the speedometer.
The later speedometer cable is square on both ends.

Ford never made a 17 tooth drive gear, I believe that someone has went to the expense to produce the 17 tooth gear to make the speedometer more accurate when changing to 3.54 gears.

I used a good original 18 tooth gear, then drove with a GPS to determine actual speed. My coupe registered 5 miles slow on the speedometer when the GPS said I was doing 50 mph; the odometer also registered lower than actual miles traveled.

I do not drive enough miles each year for me to worry about the error; let someone else lead the group which usually travel 45 to 50 MPH.

Ron

Tom Wesenberg · 10-14-2014, 05:44 PM

Sponsored Links (Register now to hide all advertisements)

If you go to fewer teeth, then the gear will be a smaller diameter and you need to change the housing to bring the gear closer to the driveshaft gear. If you can buy the 17 tooth gear and housing, that's what I would do.

billybronco1 · 12-15-2014, 07:32 PM

How many gaskets are you suppose to use with the standard 19 tooth drive gear and standard rear end? The reason I ask is three comes in the package when ordering.

Tom Wesenberg · 12-16-2014, 07:51 AM

Quote:

Originally Posted by billybronco1

How many gaskets are you suppose to use with the standard 19 tooth drive gear and standard rear end? The reason I ask is three comes in the package when ordering.

I would put the drive gear against the torque tube with no gasket, then stick a small screwdriver into the gear and try to move it back and forth to check for freeplay in the gears. If you can't feel movement, then add one gasket and try it again. Keep adding gaskets until you feel a little freeplay. Put a lot of grease on the gear before final installation.

My 10-37 housing was bad, and it took me a few swap meets to find a good original 10-37 housing and gear, but I thought I'd seen 11-39 on at least one housing during my search. I must be mistaken though if Bert's has never seen one.

OL JENNY · 12-16-2014, 10:49 AM

I have an early 1930 with the oval speedometer. I am changing to 3.54 rear end, and my cap has 19 on it and the gear is 19. Snyder's suggested the 17 tooth gear, but will it work with my 19 cap or will it chew it up like Hunter had happen?

10-13-2014, 10:43 AM	#1
Hunter Senior Member Join Date: May 2010 Location: Gaithersburg, Maryland Posts: 518	11-39 Speedometer Gear Cap Assembly I am beginning to wonder if the gear cap assembly for 1928-1929, set up for the 3.54 to 1 rear end exists. At Hershey I looked at over 50 gear cap assemblies and never found one with this marking. Also called Steve at Bert's a few months back and he didn't recall ever seeing one. Have any of you folks ever see a gear cap assembly with the 11-39 (per judging standards) marking? Thanks in advance - Hunter

10-13-2014, 11:30 AM	#2
Ron in Quincy Senior Member Join Date: May 2010 Location: Quincy, CA. Posts: 1,708	Re: 11-39 Speedometer Gear Cap Assembly Ford never produced a 11-39 speedometer drive gear when they came out with the 3.54 ring and pinion late in 1928; this gear ratio was only recommended for the roadster at that time. If you can find a speedometer drive gear marked 10-37 ,it was used on the 28's with a 3.70 rear end, it has 18 teeth on the drive gear. Also some of the dealers sell a 18 tooth drive gear and you can convert a later drive gear with 19 or 20 teeth, to the 18 teeth. This is as close as you can get for the 3.54 rear end. Ron

10-13-2014, 01:56 PM	#3
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: 11-39 Speedometer Gear Cap Assembly If you add a gear with a tooth or two more, then you might have to add a gasket or two to the housing to space it a bit farther out from the driveshaft gear.

10-14-2014, 03:01 PM	#4
Hunter Senior Member Join Date: May 2010 Location: Gaithersburg, Maryland Posts: 518	Re: 11-39 Speedometer Gear Cap Assembly Ron and Tom, Thanks for taking the time to respond to my post. I'm still a little confused. Ron thanks for sharing with me that this gear ratio (3.54) was only available for the roadster at that time. When the roadster was equipped with the 3.54 wouldn't it have had a gear cap assembly marked 11-39? A little background - when I restored my 29 Coupe I installed the 3.54 gear. It originally was equipped with the standard gear. I noticed (using a GPS) that the speedometer was registering low mph which made sense since I did not change the speedometer gear (19 tooth to 17 tooth). I spoke to two well respected vendors. One indicated that I could simply replace the 19 tooth gear with a 17 tooth gear and all would be well. The second told me that if I did that it would chew up the speedometer gear and I needed the right casing to make it all work. I took the easier path and simply replaced the 19 tooth with a 17 tooth leaving everything else the same (gear casing/gaskets). Well it registered very close to correct but after 50 miles the speedometer stopped working. I removed the gear casing and found that the 17 tooth gear was completely chewed up. So is it the case that the 10-37 gear case being the right one for the 3.70 gear (per Ron's response) that one can use a 17 tooth gear or do you have to stay with the 18 tooth gear. Do extra gaskets help eliminate the "gear chewing"? Finally, what is the difference in the actual gear casings? Is the shaft aligned differently? Is the shaft recessed to a different depth in the casing? Thanks in advance - Hunter

10-14-2014, 04:33 PM	#5
Ron in Quincy Senior Member Join Date: May 2010 Location: Quincy, CA. Posts: 1,708	Re: 11-39 Speedometer Gear Cap Assembly The difference is the speedometer cable housings; the early housings had a keyway, the later housings had a square connection. The early speedometer cable has a keyway on the housing end and square on the other end to engage the speedometer. The later speedometer cable is square on both ends. Ford never made a 17 tooth drive gear, I believe that someone has went to the expense to produce the 17 tooth gear to make the speedometer more accurate when changing to 3.54 gears. I used a good original 18 tooth gear, then drove with a GPS to determine actual speed. My coupe registered 5 miles slow on the speedometer when the GPS said I was doing 50 mph; the odometer also registered lower than actual miles traveled. I do not drive enough miles each year for me to worry about the error; let someone else lead the group which usually travel 45 to 50 MPH. Ron

10-14-2014, 05:44 PM	#6
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: 11-39 Speedometer Gear Cap Assembly Sponsored Links (Register now to hide all advertisements) If you go to fewer teeth, then the gear will be a smaller diameter and you need to change the housing to bring the gear closer to the driveshaft gear. If you can buy the 17 tooth gear and housing, that's what I would do.

12-15-2014, 07:32 PM	#7
billybronco1 Senior Member Join Date: Dec 2012 Location: MA Posts: 570	Re: 11-39 Speedometer Gear Cap Assembly How many gaskets are you suppose to use with the standard 19 tooth drive gear and standard rear end? The reason I ask is three comes in the package when ordering.

12-16-2014, 10:49 AM	#9
OL JENNY Senior Member Join Date: Sep 2012 Location: Muscatine, IA Posts: 223	Re: 11-39 Speedometer Gear Cap Assembly I have an early 1930 with the oval speedometer. I am changing to 3.54 rear end, and my cap has 19 on it and the gear is 19. Snyder's suggested the 17 tooth gear, but will it work with my 19 cap or will it chew it up like Hunter had happen?