Speedometer / speedometer drive gear

[Brianfrench65]

Originally Posted by Mitch//pa

I stand by post #3 as a potential cause for your problem

Mitch; thank you. I am going to put the rear wheels on jack stands and see what things look like, when the drive shaft turns.

Thank You;

[Brianfrench65]

Not knowing the inner workings of a speedometer, is it possible that the speedometer freezes, or locks up inside, causing the drive gear to stop and break a tooth?

Should I buy a rebuilt speedometer, and try again?

With the rear wheels on jack stands, and a wheel chock under one of the rear wheels, and me wife turning the other wheel, I still do not see any axial movement of ecentric motion from the spiral gear on the drive shaft.

Any suggestions, please.

Thank You;

[Mitch//pa]

A hanging speedo head would easily take out the cable first

[Brianfrench65]

Originally Posted by Mitch//pa

A hanging speedo head would easily take out the cable first

Mitch; I did have a cable break at the drive gear end. It broke the thin aluminum housing, that captures the nut to hold it to the drive gear housing. I was thinking something in the road hit it, but maybe this is leading back to the speedometer head.

The last couple of housings I put on, I used multiple gaskets, thinking I didn't have enough clearance. I think that's why it looks like the drive shaft gear was riding on top of the speedometer drive gear.

I have a rebuilt speedometer and will try this with a new drive gear and 1) gasket.

Thank You Very a Much;

[Brianfrench65]

The broken cable housing end that connects to the drive gear housing (turtle).

[Mitch//pa]

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That takes a heavy trauma to break gears, turtles, and the speedo cable collar..
I still think you have to much movement in the driveshaft bearing... Unfortunately it is a lot of work to replace...

If it was a speedo head issue it would just twist and break the inner cable and not do all the damage that's happening to yours.

[Brianfrench65]

Photo looking up.

[Brianfrench65]

Should the drive shaft, spiral drive gear slide towards the transmission, about 1/4" ?

That's the only movement I can get.

I put a jack with a wood dowel on it, and pressed up on the gear. I used a magnetic base indicator, and saw about 0.003 movement, when I jacked up, and applied pressure.

Thank You. I am perplexed.

[Mitch//pa]

Yes that is normal movement

[Brianfrench65]

I found this picture in my archive photograph's, and I am sure it came from a Ford Barn member, however I cannot find the post.

My question is, is the wire ring shown, supposed to lock into the drive shaft, or does it slide easyley?

Thank You;

[Tom Wesenberg]

The wire ring should snap into a groove in the driveshaft.

[Brianfrench65]

Tom; thank you. It seems like mine is not snapped in, and the existing ring seams to be sprung.

Is safety wire an alternative?

I was thinking that I could do that from the speedometer gear drive hole??

Thank You;

[Bob C]

Originally Posted by Brianfrench65

I found this picture in my archive photograph's, and I am sure it came from a Ford Barn member, however I cannot find the post.

My question is, is the wire ring shown, supposed to lock into the drive shaft, or does it slide easyley?

Thank You;

This is what Tom Endy said about the snap ring.

"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."

Bob

[Brianfrench65]

Bob; that's awesome, thank you very much

Thank You;