Datsun Roadster Forum-311s.org

Any ideas on why a 5-speed speedometer pinion carrier would refuse to budge from the side of the transmission (so pinion and carrier could be replaced with correct # teeth and alternate carrier)? The locking tab was removed, but the pinion carrier will not rotate or pull out. Pinion carrier hasn't been removed in 50 years, but trying to think of a reason it would not budge. TIA.

I had a similar case that was due to the pinion being seized via rust into the case. Lots of Blaster fluid and patience eventually got it out. Is this on a running trans?

Yes, working, original 5-speed. Existing 18-tooth pinion works, just want to change it and carrier out for an accurate 20-tooth unit.

Separate issue is speedo cable drive end snapped off in the back of the speedometer, which I will fish for with a magnet and tweezers.

I'll start a quantity order for Blaster...

Thanks.

FYI they just pull out, no threads Take a LARGE flat blade screwdriver and put it under the notch the the hold down rests on and pry it up.
Dave

Dave,

Lever the screwdriver blade under the carrier notch, against the case, and outward?

Thanks.

afaik the transmission end has a 17mm?? area - use an open end wrench and rotate it pulling on the cable.

I'll check for a 17mm flat. Using cable (to be replaced, anyway) as a pulling device makes sense. Thanks.

Dave,

Thing to note

Bigger (more toothed) pinions are not necessarily a 'drop in' and unless you are using the appropriate carrier for your pinion, it is unlikely to work, easily. This is because the carrier actually has an offset built in which positions the central pivot point AWAY from the 'driving' gear inside the transmission. So you need to be sure that the pinion is not too tight, otherwise the teeth will be ground off in a heartbeat. Not knowing what option you are using, hard to caution further, but just be aware!

Using the correct carrier for the factory installed 20 tooth pinion. Re-clocked the carrier for the locking tab.

To get the pinion carrier out of my transmission I bought a nut of the same threads, tightened it down until it broke free and spun. The screwdriver in the slot resulted in the carrier laughing at me. Fool, I will never give up.

No 17mm flats on the carrier, and the locking tab notch is too narrow for a one-sided grab ... still wrestling with the carrier.

the flats are on the cable - you should also be able to use a BF screwdriver inserted in the retaining cutout!

Maybe/probably on the cable. The metal is kind of weak. If you have a used cable that would be good. I say go nut(s) on it.

Torquing the speedo cable, which spins within the carrier, will have no effect on freeing the carrier from the transmission case, it will only attempt to back-drive the transmission shaft with its attached metal gear. If the speedo cable doesn't fail in torque, it's likely to strip plastic off the pinion. Lose - Lose, as far as I can see. Thanks, though.

So long as the cable inside the cable housing is not engaged the carrier will just spin around the pinion. Or course that involves the pain of climbing under the dash to take the cable off the speedo.