Live Axle dif Ratio

[Gun Bunny]

Trying to calibrate a SPA digital speedo but need to know the dif ratio as part of the calculation. Without taking the dif out & counting teeth what possible ratios can I choose from for a live axle.

 

Yes I know a bike speedo is cheaper and easy to set up.

 

Thanks

[wonkey eyed barmaid]

AFAIK common ratios are

3.73

3.89

4.11

for ital axle

[Violet Elizabeth]

3.27 also.

 

Most likely a 3.89 with 4 speeder I think.

 

 

[Nigel Riches]

Just to confuse things further I'm fairly sure that mine is 3.6:1, and was original fit in 1982, with a 4 speed box, X-flow motor.

 

1982. 5 speed, clamshells. B.R.G / Ali. The True Colours.

[I.Mupferit]

My original Ital diff was 3.6:1 which, I think, was standard fitment with a 4 sp 'box and 3.9:1 with a 5 speed.

 

Brent

 

2.3 DURATEC SV Reassuringly Expensive

R 417.39 😬

[Violet Elizabeth]

Why did my 4-speed have a 3.89 then Oh yes, EFA built it

 

 

[I.Mupferit]

Explains a lot ❗

 

Brent

 

2.3 DURATEC SV Reassuringly Expensive

R 417.39 😬

[Archie Procter]

Scholarship/Academy/Grad 5-speeds are 4.11

 

Andrew

[DaveMorris]

I think that this works -

You could jack up one rear wheel, chalk mark the diff/prop and tyre.

Then get some nice kind person to SLOWLY rotate the tyre one revolution. Count the revs of the prop.

Diff ratio is (IIRC) the inverse of twice the number of revs that the propshaft made (or the inverse of of half of it ) One or the other.

 

Dave

[DaveMorris]

Q187 of Dorset -

 

Does it work ?

 

Dave

[Gun Bunny]

Thanks for all the help.

Dave the answer is YES & NO

YES the principle works but NO as I cant get a reliable and accurate answer. Have now admited defeat and fitted the sensor to the brake disc.

[cskip]

Noger - Yours didn't have a 3.89 it had a 3.63........

 

Skip.

 

West Hants Luddite

See CSKIP here