being a bit thick?

[marcusclive]

Whilst fitting new bushes on the back of the stag i thought i would replace the oil seals on the diff. All well and apart from needing a 1 1/8 socket to remove the output shafts, not a problem i will order one on Monday. However whilst laying on my back under the car i thought i would check the diff ratio. As i understand it the diff ratio should be 3.7 :1. Now to me this would point to the diff output shafts turning 3.7 turns to 1 of the input ie prop shaft. Mine does 2 turns, what am i doing wrong?
Marcus.

[Ian Durrant]

it should be 3.7 of the input to one for the output. its hard to do this because the differential unit is designed to allow the rear wheels to spin at different speeds, so you might have one wheels that's a bit tighter than the other on the brakes and that wheel isn't turning. You then get a different gearing effect on the one that is turning. So then you'd get less turns of the input to one of the wheel that is turning.

The only real way to check is to turn both rear wheels through one revolution and count the turns at the propshaft.

HTH

[richardthestag]

with the diff off the car and a bolt through each output shaft drive flange I marked a dob of tipex on the end of the input shaft and aligned it with one of the bolt holes for the diff nose. then wound both output shafts at the same time, direction and speed for one turn and count how many times the tipex on the input shaft goes past the bolt hole.

simples
compare_the_meerkat.jpg

[marcusclive]

Ahh, cheers gents, will try tomorrow when doing the brakes.

[richardthestag]

obviously a white stag thread this one

[jamcarr2]

is it not stamped on the case ..how would you know what you are buying if you got a second hand one
Not all white now is it

[Bob Heritage]

is it not stamped on the case ..how would you know what you are buying if you got a second hand one
Not all white now is it

Seems all white to me - even got a lighthouse joining in now.

[richardthestag]

is it not stamped on the case ..how would you know what you are buying if you got a second hand one
Not all white now is it

By doing what I said above turning output shafts and counting how many time the input shaft moves.

IIRC the choices are 3.7 and 3.45 (trummie 2000 diff but very useful for BW35's) it is very obvious difference between the two 3 and 3/4 turns verses just under 3 and 1/2 turns

I had a 3.45 on mine when it was auto but the diff didn't suit the Man o/d so I swapped out for a 3.7 and happy days.

IIRC there are marks on the bottom of the diff but no guarantees that somebody hasn't replaced the guts at some point

[Stagdad]

Definatly a white thread.Oh yes and if you test the diff and it takes 3.25 or 3.64 turns of the input shaft someones sliped a beamer diff in there when you wern't looking

Cheers Steve

[marcusclive]

Yep its a proper diff, whilst lying on my back i turned both drums at the same time and it turns the prop 3 3/4 turns.

[StagnJag]

I seem to recall that the nuts on the output shaft were originally coloured to indicate what ratio was inside - mine are coloured yellow.

Again - this assumes the innards haven't been replaced at some point!

Rgds

Dave