Which speedo drive gear with type 9?

[peej 2]

Hi,

 

Ive got a type 9 that Im going to swap in to my mk3, and Id like to sort out the speedo drive gear before the gearbox is on the car.

 

I believe someone has a way of working out which speedo gears to use.

 

My car has the following.

 

175/70 R13 tyres

3.75 : 1 axle

 

 

The type 9 currently has

 

7 start worm gear

23 tooth plastic cog

 

It would be nice not to have to swap the worm gear. Is the 23 tooth cog the right one?

 

Thanks for your help

 

Cheers

 

Paul

[Danish 294]

Are you in the mtoc? One of the members (Gareth?) Did a spreadsheet of all the combinations.

Edited April 6, 2018 by Danish

[markymarkthree 160]

Are you in the mtoc? One of the members (Gareth?) Did a spreadsheet of all the combinations.

 

I think it may have been Steve (TEAM RADIUS) . :juggle:

[peej 2]

Yes I'm in the MTOC. Is the spreadsheet up on the MTOC forum somewhere?

[Danish 294]

I think it may have been Steve (TEAM RADIUS) . :juggle:

 

 

Could be. :thumbup:

[sheffieldcortinacentre 530]

You need one from a 2.0 4 speed ( can't remember tooth count/colour though).

[peej 2]

I've messaged Team Radius on the MTOC forum. I'll see what he says.

[team_radius 8]

Hi Paul,

 

I've just replied on Cortina MK3 site. The Type 9 you have is spot on. The worm gear and drive cog combo you have is the best fit at only 1.6% out.
The next best is 7 & 24 at -2.7% out, then 7 & 22 at 5.9%.

You will find that Ford designed speedos to over read at higher speeds to stop folk getting done for speeding, so at say 70 mph speedo speed, the Sat nav wil say 67 mph ish actual.

 

Cheers

[peej 2]

Thankyou very much.

 

That's great.

 

:thumbup: