The 510 Realm

Has anyone on the realm done a 6 speed gearbox with their SR20DET?
My question is regarding the speedo.
I have done one of my 1600's (510) with a 6 speed and a cable-x electronic to mechanical speedo drive. This works well until about 60mph but after that the speedo needle wavers all around and it is impossible to know the correct speed. Is there a better way? Also, on some of the earlier sr20det 6 speed boxes the tail shaft housing has a moulding where the speedo drive should be but it's not machined out, is it possible to machine it out and fit a speedo drive? I imagine the output shaft hasn't got the corresponding gear teeth machined so that could also need attention. Does anyone know if it's possible to do this?
Hopefully what I've written is understandable. Thanks in advance for any info.

Bernie. New Zealand.

Hi Bernie,

I have one I'm adapting to my L series. I hunted around for an early one so that I would have the ability to run my 1600 speedo drive with it. The speedo drive out of a L series gearbox fits in these perfectly apparently. There is no worm gear on the output shaft, but you can machine an L gearbox one up slightly to fit. On gearboxes that are machined to take a speedo drive there is already a divot for the ball bearing and two circlip grooves to hold in the speedo drive gear. Gearboxes without the machined housing don't have the circlip grooves or bearing divot.

It is possible to machine the rear housing of the S15 box to take a speedo drive, you would just have to disassemble your box and machine the shaft to take the worm gear or find an alternative method of securing it.

John, New Zealand.

Ok, thanks Hohn. I heard a rumour tat it was possible but I didn't know the details.
Bernie NZ

John! Bloody fat fingers!

Good luck getting that bore aligned to mesh the speedo gears together. But if the trans hasn't the circlip or locating divot for the ball I wouldn't bother because you would have to pull the trans apart to get those machined. If you have the later dash with round speedo I'd simply put a GPS unit in.

Early and 71B transmissions, the mainshaft was machined. On the 71B there were metal or plastic. Top is a '79 zx, bottom is an
'85 720 diesel.

Three B's Racing wrote:Good luck getting that bore aligned to mesh the speedo gears together. But if the trans hasn't the circlip or locating divot for the ball I wouldn't bother because you would have to pull the trans apart to get those machined. If you have the later dash with round speedo I'd simply put a GPS unit in.

If he's trying to run through certification he won't be allowed a GPS speedo for legal reasons.

broke wrote:

Three B's Racing wrote:Good luck getting that bore aligned to mesh the speedo gears together. But if the trans hasn't the circlip or locating divot for the ball I wouldn't bother because you would have to pull the trans apart to get those machined. If you have the later dash with round speedo I'd simply put a GPS unit in.

If he's trying to run through certification he won't be allowed a GPS speedo for legal reasons.

And we're supposed to know this how? and how would they know it's a GPS when the sensor can be hidden?

Just Sayin"

Three B's Racing wrote:

broke wrote:

Three B's Racing wrote:Good luck getting that bore aligned to mesh the speedo gears together. But if the trans hasn't the circlip or locating divot for the ball I wouldn't bother because you would have to pull the trans apart to get those machined. If you have the later dash with round speedo I'd simply put a GPS unit in.

If he's trying to run through certification he won't be allowed a GPS speedo for legal reasons.

And we're supposed to know this how? and how would they know it's a GPS when the sensor can be hidden?

Just Sayin"

I dunno, I assumed since he announced his location that he wanted local regulations to apply. Then again, I also assumed he knew that his factory box would have a speedo drive, so maybe I was being presumptuous. I guess you showed me.