hey guys..im currently chaising a 3:23diff so when i finish the manual conversion on my ef my speedo wont be out...if i was to get a 3:45 diff with my T5 how would i make the speedo read correctly? it currently has a 3:08 diff and is a 95 futura.

My ED manual had a 3.27 diff std with 15" wheels...

I now have a 3.45 LSD fitted with 17" wheels which are close to the overall rolling circumference of the 15" wheels and I run the grey 21 tooth speedo drive gear and then to make it spot on at 50km hr I pulled the speedo needle off and trimmed it so it was spot on at 50km/hr and I read 102 on the speedo when I do 100km/hr so this works fine for me...

16" wheels are smaller rolling circumference than 17's and you need to run the black 22 tooth gear to accommodate...

You can adjust your speed a little bit by picking an odd tire size (width vs profile) and make or lose a bit that way... Or by getting Jaycar's speedo corrector and making the kit and using that... Once guys go to 3.7 3.9 or 4.11 there isn't a gear for these ratios and you need to electrically modify the signal...

Cheers,
Tim

iv gone from the std 15" fairmont/futura wheels to 16" XR wheels..if i get the 3:45 LSD diff and stick with the manual conversion what will i need to do to make my speedo read right? i have no idea how this stuff works lol

Black 22 tooth gear as Tim said.It is fitted to the speedo transducer that bolts into the gearbox.
The fact that it is now a manual makes no difference to the speedo reading.

Sooo... The car manual 'box came out of had a 3.23:1 diff? Just throw the speedo drive from your auto into the T5. The speedo will read exactly the same.

If you were to change the diff ratio to 3.45, you will need to change the gear as Timmy said above.

sounds easy enough ...do i get that gear from ford? are they expensive?
looked up the catch code of the manual ECU i have in google and it linked me to a thread on here...some one said a 3:23 ratio diff with the manual ECU will have my speedo reading right but as far iv had better luck finding 3:45 ratio diffs lol..so i may aswell just get a 3:45 and the correct gear

The gears are no longer avilable from ford... I stripped mine a month or so ago and got a replacement and a spare from here:

http://www.ebay.com.au/itm/120976451040 ... 1497.l2649

He has a few spares left over... Once they're all sold these things will be hard to come across...

Manual gearboxs ran a 3.23 only to make it easier to take off in as auto's slip but this made the manual more driver friendly...

I have a 3.45 only because it is a LSD and I couldn't justify getting a true trak and didn't like my locker... The 3.27 to 3.45 really made no noticeable difference to me...

Yeah as i said 16" wheels with the std tire size (225/50/16 or something like that?) will need the black 22tooth gear because you have to spin the wheels quicker to do 100kmhr because they're smaller... This would cause the speedo to read faster than 100kmhr at that speed so to slow that you make the driven gear bigger, in the case of a falcon by 1 tooth... From 21teeth for 17's to 22teeth for 16's...

Cheers,
Tim