Keep Snapping Speedo Drives

[Mohsen]

Hey guys, i keep snapping speedo drives on my rb25 box. using a d21 sender and r33 gear on it.
worked for 20 kays before the shaft snapped.
what am i doing wrong? can i just connect something to the ecu speed wire and be done with it?
thanks

[jiffo]

Are you using the correct pinion for the drive's location?

Haven't worked on a 25 box but 20's etc have the drive mounted eccentrically to accommodate various pinion sizes.

You select your pinion size then rotate the whole assembly to mesh correctly onto the nylon drive gear.

Then re-work the locking tab slot to hold the assembly in the different position.

I'd guess most Skyline owners wouldn't bother altering pinion sizes but back in the day when fitting Rb20's into Commos with their tall diff ratio, you had to swap out the pinion to get anywhere near an accurate speedo.

[Mohsen]

did swap the gear but didnt slit the housing....