Speedo Drive

W

Wooden wheel

Junior Member
Greetings fellow Ford Barners My speedo on my1930 Phaeton has stopped working and I have found the fault is in the drive gear on the drive shaft. The drive gear on the drive shaft has moved back and become disengaged from the spline. Can I repair this without removing the drive shaft and diff. Fingers crossed that one of you ford gurus can save me a lot of work. Thanks in anticipation.
 
The drive gear will float back and forth approx 1/4"without the turtle installed! And is held in place by the driven gear assy.
I am not sure what you mean by "disengaged from the splines"
 
Hi there Mitch/ pa, I have been thinking about it over night and wondering if the gear has worn and by pushing it forward it is locating on a non worn section on the spline. I have located another diff and drive assembly so will pull torque tube off that and see how it all fits together. Thanks for your input.
 
I just changed out the speedo driven gear in the 9-34 case and noticed for the 1st time that the driveshaft gear also moves back and forth along the shaft as Mitch states. The retaining ring clip I suppose should be checked as well.
 
I don't see how the speedo drive gear could possibly wear such that the it will not engage the splines on the drive shaft and it is not possible to install it backwards.

Over the years of taking rear axle assemblies apart I have noticed that there is a space, maybe 1\8" between the front of the drive gear and the circular snap ring. I have come to the conclusion that the snap ring is not there to position the drive gear as the driven gear assembly will do that when it is installed. I suspect Henry put it there so that the rear axle assembly could be transported down the assembly line hung up-side-down and the snap ring kept the roller bearing, thrust washer and drive gear from falling out. The driven gear assembly was probably installed later when it was installed in a car and determined what gear size to use for the driven gear.

The thrust washer installed behind the drive gear has a series of holes around the circumference to allow grease to flow through to the roller bearing when pumped in through grease fitting on the rear bearing retainer on the transmission.

Every now and them I find an assembly where someone has installed two thrust washers in an attempt to eliminate the space between the front of the drive gear and the snap ring. This not a good practice as the two washers can easily block off the holes and the grease will not go through.

Best not to worry about that space, Henry may have put it there to confound and confuse the next 100 years of Model A enthusiasts. There is a Howard Barns drawing of the assembly in Bratton's catalog.

Tom Endy
 
Tom Endy said:
I don't see how the speedo drive gear could possibly wear such that the it will not engage the splines on the drive shaft and it is not possible to install it backwards.

Over the years of taking rear axle assemblies apart I have noticed that there is a space, maybe 1\8" between the front of the drive gear and the circular snap ring. I have come to the conclusion that the snap ring is not there to position the drive gear as the driven gear assembly will do that when it is installed. I suspect Henry put it there so that the rear axle assembly could be transported down the assembly line hung up-side-down and the snap ring kept the roller bearing, thrust washer and drive gear from falling out. The driven gear assembly was probably installed later when it was installed in a car and determined what gear size to use for the driven gear.

The thrust washer installed behind the drive gear has a series of holes around the circumference to allow grease to flow through to the roller bearing when pumped in through grease fitting on the rear bearing retainer on the transmission.

Every now and them I find an assembly where someone has installed two thrust washers in an attempt to eliminate the space between the front of the drive gear and the snap ring. This not a good practice as the two washers can easily block off the holes and the grease will not go through.

Best not to worry about that space, Henry may have put it there to confound and confuse the next 100 years of Model A enthusiasts. There is a Howard Barns drawing of the assembly in Bratton's catalog.

Tom Endy
Click to expand...


me either
 
Greetings guys, Problem sorted. It turned out that the problem was in the small gear at the drive shaft end of the cable. Some one had done a QUICK repair !!!! to the Key type mark on the shaft so replaced this and all go. Very many thanks to you all that provided info
 
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