R32 - Rb25 Engine & Box / Speedo / Temp Gauge / 4th Gear Synchro

[kresot9]

I have some issues and i would like to know how i could go on fixing them as i never dealt with these issues before.

I recently bought a r32 with rb25 engine and box, 4.3lsd and custom one piece tail shaft.

Firstly, the speedo is out of whack, the needle wobbles back and forth at the very start 10-30kms roughly at 40kms it starts working, the speedo is out but around 10kms below 70kms but after that it starts to be 20kms and at driving 100km the speedo will say 125ish kms. The gearbox as a vl turbo speed drive and can anything be done to fix it a bit better. My car has a gtst cluster the grey one. Can the speedo be calibrated for mechanical?

The 4th gear crunches not a lot, but enough you can feel and notice it, i have read around the synchro has gone or something and usually a rebuild is required, the other gears are perfectly fine. Some people have said using certain oils and it will help remove it.

The temp gauge isn't working at all, the person i bought the car said it needs the rb20 not the rb25 sensor and not sure where it is located or how to get it fixed. Have spoken to someone else and they just got a saas gauge and put inline adapter on coolant hose and works perfectly then.

Any help would be awesome

[kresot9]

http://www.sau.com.au/forums/topic/186140-mechanical-speedo-sender-for-the-r33-rb25det-gearbox/

It seems like due to my 4.3lsd the difference and the 25gearbox i would need a 21 tooth speedo gear from a post from here, or either i swap the diff to any of 3.45-3.5:1 ratios, any other where i can get a 21 tooth speedo? The link above states its no longer available they can be purchased for 300+ from japan

http://forums.hybridz.org/topic/68137-mechanical-speedo-drive-swap-into-rb25-gearbox/page-3

from the site above a guy found a nissan part that offers a 21 tooth speedo, part number 32703-31G21

[kresot9]

All good i did more research and got some more info, and found out a post about using a 20 tooth pinion from a r33 rb25 gearbox even though its useful on 4.1 diff ratios it still work good with 4.3