Which cog to use for speedo after fitting 3.45 diff?

Home » Forums » Fordmods Tech » Gearbox, Suspension, Brake & Driveline Workshop

Page 1 of 1 [ 10 posts ]

Post New Topic Post Reply

Previous topic Next topic

DEVEL

Post subject: Which cog to use for speedo after fitting 3.45 diff?

Posted: Wed Jun 14, 2006 7:50 am

Parts Gopher

Offline

Age: 43

Posts: 57

Joined: 23rd Feb 2005

Gallery: 1 images

Ride: EL Futura

Location: Melbourne
VIC, Australia

Hi guys as the title suggests, which cog do i use to correct my speedo reading?
I now have a 3.45 LSD fitted with 17" rims. Im pretty sure i have to use the black 23 tooth one but am unsure..... i rang ford and asked them but they werent convincing as they said the 22 tooth is for 15's and the 23 tooth is for 16's. So which will be best for 17's???

Top

Profile

Disco Frank

Posted: Wed Jun 14, 2006 8:59 am

Fordmods Junkie

Offline

Age: 45

Posts: 1000493

Joined: 6th Nov 2004

Gallery: 2 images

Ride: AUXR6 HP With Ducati SupA Bike!

Location: Perth
WA, Australia

black cog dude!

_________________

RIP SCOTT

Top

Profile

DEVEL

Posted: Wed Jun 14, 2006 9:27 am

Parts Gopher

Offline

Age: 43

Posts: 57

Joined: 23rd Feb 2005

Gallery: 1 images

Ride: EL Futura

Location: Melbourne
VIC, Australia

thanks for the info!

Top

Profile

kezz

Posted: Wed Jun 14, 2006 12:03 pm

Getting Side Ways

Offline

Age: 37

Posts: 2256

Joined: 5th May 2005

Gallery: 1 images

Ride: 5 Star Boxcar

Location: blu mtns
NSW, Australia

im 99% sure its the grey tooth for 3.45 and 17inch wheels. thats what ford gave me.

_________________

Kezz's 5sp Box Car ---> RPD enhanced with a bunch of other stuff

Top

Profile

DEVEL

Posted: Wed Jun 14, 2006 12:13 pm

Parts Gopher

Offline

Age: 43

Posts: 57

Joined: 23rd Feb 2005

Gallery: 1 images

Ride: EL Futura

Location: Melbourne
VIC, Australia

so the grey one is the 22 tooth cog???

how accurate is your speedo now with the grey one?

anyone else know which is best?

Top

Profile

Steady ED

Posted: Wed Jun 14, 2006 12:17 pm

Fordmods Addict

Offline

Age: 38

Posts: 7958

Joined: 1st Jun 2005

Gallery: 13 images

Ride: Falcon

Power: 237 rwkw

Location: Melbourne
VIC, Australia

I think you are supposed to use the grey one, apparently 225/50R16s are a slightly larger diameter then 205/65R15s and 234/45R17s, which are almost identical.
Having said that, I've got a black one with my 17's and 3.45 diff, and speedo is fairly accurate, AFAIK.
Have a play with the 'Speedo Calculator' in the Technical Documents section.

_________________

ED XR8 Sprint - S-Trim, V500, 249rwkw
BF MKII F6 Tornado - 237rwkw

Top

Profile

eed-250

Posted: Wed Jun 14, 2006 2:23 pm

Getting Side Ways

Offline

Posts: 1687

Joined: 5th Nov 2004

Gallery: 5 images

Ride: 1994 ED Ricer

Location: Perth
WA, Australia

ive got a black one too

Top

Profile

DEVEL

Posted: Wed Jun 14, 2006 2:39 pm

Parts Gopher

Offline

Age: 43

Posts: 57

Joined: 23rd Feb 2005

Gallery: 1 images

Ride: EL Futura

Location: Melbourne
VIC, Australia

i didnt know about the calculator - thanks!!!

however one thing is does anyone know what cog was used for my standard 3.08 diff?
and are 15s standard for a 96 EL Futura as i thought 16s were!!

Top

Profile

kezz

Posted: Wed Jun 14, 2006 4:17 pm

Getting Side Ways

Offline

Age: 37

Posts: 2256

Joined: 5th May 2005

Gallery: 1 images

Ride: 5 Star Boxcar

Location: blu mtns
NSW, Australia

i pulled a black cog outta my gearbox when the 3.08 was in there. i had 17's on my car too

_________________

Kezz's 5sp Box Car ---> RPD enhanced with a bunch of other stuff

Top

Profile

DEVEL

Posted: Mon Jun 19, 2006 9:58 am

Parts Gopher

Offline

Age: 43

Posts: 57

Joined: 23rd Feb 2005

Gallery: 1 images

Ride: EL Futura

Location: Melbourne
VIC, Australia

well new gear is in.... i went with the black one, speedo is about half a k out in my favour eg 100.5 on speedo actual speed is 100

thanks for everyones help.

just for future reference i pulled a brown 20 tooth gear out - it was matched with 3.08 originally

Top

Profile

Post New Topic Reply

Page 1 of 1 [ 10 posts ]

Jump to:

Home » Forums » Fordmods Tech » Gearbox, Suspension, Brake & Driveline Workshop

Who is online
Users browsing this forum: No registered users and 28 guests

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

It is currently Fri Dec 27, 2024 3:59 pm

All times are UTC + 11 hours