Datsun Roadster Forum-311s.org

Good morning! We finally have some decent weather so I decided to drive the roadster into work. It hasn't been out of the garage since october... She was stubborn to start as she is cold blooded, but finally kicked over and I let her warm up. I back it out of the garage and into the drive way. That is when I noticed these two parts under on the floor. They were coated in oil, not alot. I thru a box under the car while it was warming up to see if it was leaking while running, nothing. So I decided to take it to work. She ran fine and temps and oil pressure was fine. But my speedo doesn't work. I am assuming this has something to do with the speedo cable? I only work about 5 miles from home, so also wanted to know if its safe to drive it back?

Thanks for all the help!

Is it part #76, 77?? If so, what is it?

I’m not familiar with the 4 speed, but it sure looks like the speedometer pinion gear. Did your speedometer suddenly quit working?

The small piece looks like the end of the speedo cable that goes into the pinion drive on the transmission. The gear piece doesn't look familiar to me. Part 76 is in a carrier (part 77) and is held in the carrier with a small roll pin. The carrier mounts to the transmission case with a wedge (part 80) and a single screw. It would be very unlikely to have 76 out without 77. Look at the passenger side of the transmission and see if the speedo cable is loose, hanging. Also look at the tach cable at the base of the distributor. Might be a tach drive part? I assume you have a stock 4 speed trans and a R16 engine...?

Here's a pic of the speedo drive gear in the carrior (not from a roadster but pretty close). The slot in the carrier case is where the roll pin goes

jrusso07 wrote: Sat Mar 18, 2023 1:32 pm The small piece looks like the end of the speedo cable that goes into the pinion drive on the transmission. The gear piece doesn't look familiar to me. Part 76 is in a carrier (part 77) and is held in the carrier with a small roll pin. The carrier mounts to the transmission case with a wedge (part 80) and a single screw. It would be very unlikely to have 76 out without 77. Look at the passenger side of the transmission and see if the speedo cable is loose, hanging. Also look at the tach cable at the base of the distributor. Might be a tach drive part? I assume you have a stock 4 speed trans and a R16 engine...?

Thanks for the input! Yes stock 1970 R16 with 4 speed. Tach still works. I will try and investigate while at work but can't get under the car until I get home and can jack it up. Speedo worked last time I drove it. It was not accurate but it worked...

The two parts in the picture, the smaller on slides into the larger one and has a "key" that slides into a grove of the shaft of the larger part that has the gear. Not sure if I am explaining that clearly.

Again, thank you for any and all help!!

What you describe (key into groove) is how the speedo cable fits into the speedo drive gear in the trans. The gear doesn't look correct for the 4 speed - maybe it was altered in some way?

Here's a pic of the speedo drive gear (76). Note the slot to accept the key on the speedo cable The gear in your picture looks like the tach drive gear (#13) in the diagram below

The car was "restored" approx 9 years ago. I don't have any contact info from the person that did the resto. It's supposed to be an all original drivetrain. It does have aftermarket gauges? I don't know if that matters?

Well these are the best shots I could get with my "Ghetto Ramp"...

i'm pretty sure the parts you pictured are from the tach drive. I wondering if the new gauge tach is electronic and not requiring the cable. if so, you still need to seal up the tach drive output at the base of the distributor. Still a mystery why the speedo stopped working

Can't be the tach drive if it's working, and it's easy to see as its on the distributor mount. Those pieces must be from the speedo... broken cable for sure, but it looks like the mount it out or broken too. I believe this will allow trans oil to leak out, so do check asap, and if it's dry I'd remove the fill hole, stick a finer inside and see if you touch oil. If not, don't drive the trans without gear oil!

Sorry for delay. Had to go out of two for a week. Just jacked the car up and found this at the connection of the Speedo cable. I feel like it’s missing a cap or top that would hold this piece in there. Anyone know what type of part this is? Ie part number?

Thank you!

Here is a used one on eBay with multiple photos, maybe it will shed light on the situation?

https://www.ebay.com/itm/204032665338

and a new one from Rallye's website

http://www.datsunroadster.com/PIC_PAGES ... 327-16.htm

DAC21 wrote: Wed Mar 29, 2023 3:11 pm Here is a used one on eBay with multiple photos, maybe it will shed light on the situation?

https://www.ebay.com/itm/204032665338

and a new one from Rallye's website

http://www.datsunroadster.com/PIC_PAGES ... 327-16.htm

Mahalo!!!!

YUP, there is a brass cap, similar to the other one.