transmission

[BILLY BLACKARROW]

Hi all
Doe's anyone know a formula to work out what gearbox gear (gear in gearbox ) to speedo to use for a 305 chev /turbp 350 i think the roll measurement may be needed but at this point in time that is unknown till tomorrow hope you know what i mean.
Billy

[Errol62]

Best way I've found is road test Billy. Not much help if you don't have a gear to start with. They usually have around 20 teeth. Each tooth you add slows the Speedo by around 5%.

FB ute driver, EK van project

[WesternWagon]

Few calculators on line that may help

Regards

Gazza

[Harv]

You'll need to know what colour drive gear is already inside the box. You can then pick a driven gear to suit (can change both if needs be).

viewtopic.php?f=27&t=18598&p=189353&hil ... ur#p189353

Cheers,
Harv

[Blacky]

Billy , TCI transmissions website has a real good calculator, also tells you what colour the gears are so you can see the colour of your drive gear inside the box and try and match a driven gear to it - all you need to know is your diff gear ratio and rear tyre size , if you don’t know tyre height there is a calculator to work that out online too just Google tyre size calculator and put your size in and it will give you the height

[BILLY BLACKARROW]

http://www.tciauto.com/tc/transmission- ... gears.html
Blacky I found the website you suggested but cant find the calculator
Harv read your earlier post ( a bit technical for me never was any good at math )
Where can i buy the gears locally any ideas

[Harv]

TCI calculator:
https://www.tciauto.com/speedometer-gear-calculator

Speedo gears are available from Rocket.
https://shop.rocketindustries.com.au/products/TCI880007

Cheers,
Harv

[Blacky]

here it is mate -

https://tiresize.com/calculator/