Speedometer troubles

[misspentyouth]

First of all I would like to give thanks for the assistance I received on carbs.  I replaced my stock carb with the suggested Webber and I must say that it was an easy install and my motor grew teeth and now runs like an angry beast.

 

On to my new problem. I have been troubleshooting my non-working speedo.  I just pulled the drive pinion out of the tranny and the gear is worn smooth on one side and the shaft does not spin freely.  The whole assembly needs to be removed and replaced.  The gear is red and is made of plastic.  Do you know where I can obtain this particular part.  I called the Nissan parts dealer, they were of no help.

 

I would love to show pics of my sweet one-owner 620 but I cannot figure out how to post pics. Directions on this would be appreciated as well.

 

Thanks again to the help I have received from the ratsun forum.

[datzenmike]

Red is the correct 4 speed pinion gear. The Nissan part number is 32703P2620. about $15 but you will need to push out the roll pin in the side of the sleeve and pull the spindle with the red gear on it out. Slip in the new and pit in the pin.

 

Have never heard of these being ground away like this. When you took the pinion sleeve out was the bolt and key that locks it in place above it of below it?

Above

 

Below

[misspentyouth]

I found a new gear on a Datsun Z website for 16 bucks. The truck had not been driven for about 13 years, it had just sit in a garage. This apparently caused the shaft going to the pinion gear to seize up with gunk within the housing itself. The shaft being seized caused the gear to get flat spotted where it was engaged with the gear inside the tranny. the bolt and key were located above the speedo cable mount like the first pic you illustrated. Should have it repaired sometime next week. Thanks again!!

[datzenmike]

Make sure it's from a '79 or older car or truck. Compare your old one and the new one carefully, there were changes made to '80 and on pinions.
See the key way cut on the lower left? Same right? Now look at the gear placement, left is to the left. right to right. Roll pin is on different side too.


Clean O ring and you can reuse it. Grease it up and the plastic gear and push straight in with the key way lined up. Do not twist side to side.