Re: Speedometer cable works?

Posted by Bob Carabbio on February 15, 1998 at 13:15:36

In Reply to: Speedometer cable works?
posted by TONY OLINGER on February 14, 1998 at 22:37:05

I'm not sure what you have or don't have BUT
As far as the driveshaft goes -
starting at the differential forward to the universal.
The driveshaft seal goes in with the lip facing the universal joint.Then the driveshaft bearing - make sure the bearing outer race is in good shape - no pitting etc.Then the thrust washer, the speedometer drive gear with the GEAR end of the drive gear toward the universal.finally the snap ring that should click into the groove in the spline.
THEN on the bottom of the torque tube, there's an aluminum housing that bolts on with a gasket that holds the driven gear, and the speedo drive shaft.
There are two different ratios, and two different drive styles.the drive gear on the driveshaft is all the same.
The standard ratio is for a 3.78:1 (9-34)rear end and should have 19 teeth on the driven gear.The option is the 3.54:1 (11-39) rear end, which takes an 18 tooth driven gear.
Generally Oval speedometers in the earlier cars used a round keyed end on the speedometer cable where it attaches to the torque tube drive, and later round speedometers use a square drive end at at the torque tube.All speedometers are square drive.
If you assemble the gearbox onto the torque tube, and there's NO free play between the gears (test by rotating the shaft in the speedo drive), then you'll need to add a second gasket to provide some clearance. If it's real sloppy, then the gasket can be left out and replaced by some blue Permatex RTV gasket compound. If it's still sloppy, you need new gears - probably only the driven gear.
When you assemble the torque tube onto the back of the tranny, then remove the back bolt from the speedo drive housing, and pump grease into the universal until it comes out the bolt hole.
Any missing part you need are available everywhere - Snyder's Bratton's etc. - or you friendly local swap meet when it rolls around.
Bob Carabbio

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