Old Leafsprung Land Rovers

I'm not sure about markings, but you can jack up a rear wheel (in neutral, 2WD, handbrake off), give the wheel one full turn and count the number of times the propshaft turns (mark it with chalk to make it easy to count).

Do the same with the front (in 2WD with FWH engaged) and if the diffs are the same, the prop should turn the same number of times.

I seem to recall with 4.7:1 (original) diffs the prop should turn twice that, ie. 9.4 times.
With 3.54:1 diffs it should turn 7.08 times.

 

Check as RMS says, you will get around 1 3/4 turns of prop with 3.54 diffs fitted.

Aha, have I got my maths the wrong way round then   

Thanks for the advice lads-will do the revolution test tomorrow night! Lucy..Only a filler on the rear diff
Would a miss matched gear ratio show itself up like I described within a couple of metres? The other thing is that it could have been driven with the hubs unlocked for ages so could the lack of things turning & being lubed proper maybe cause this dragging im strying to describe?

I dont know if all RR diffs had a filler plugs,(Ive had some that were reportedly RR but didnt have filler plugs) part no.s may tell you what you have if evident, If you do have two differing ratios my guess is the rear is 354 and the front is 471, just because of the time and hassle it takes to change a front one.

My rear rangey diff does not have a filler and I fill down the hubs.

You need to lock both front hubs to do the 'prop revolution' test, otherwise the halfshaft in the unlocked hub spins and the prop stays still, as you found.

It sounds like you're in 4WD if it seems to be jamming - if you've got another jack try lifting a rear wheel as well to see if that turns when you rotate the front wheel. (assuming handbrake off).

Check the yellow knob lever, push it down with the red lever in the forward (Hi) position. The yellow knob should stay down.

Pull the red lever back and the yellow knob should pop up (about 2" or so).

If the yellow knob doesn't stay down, or if it doesn't pop up when you pull the red lever back, it sounds like you're stuck in 4WD   

Cheers,
Robin.

Robin, thanks for the tips! Firstly, the 4wd knob was pressed down so after pulling the red lever to & fro, its released as it should .Tried it again with hubs locked & the landy rolled forward perfectly compared to feeling braked yesterday!
Next I jacked both front wheels of the ground and with the hubs locked rotated the wheels & hey ho, the prop turns After this I checked the prop rotation and it turned 1.75 times which seems to indicate as you said, that a 3:54 diff on the front & 4:77 on the rear
With that identified, I did the last test you recommended and jacked a rear up too & rotated a front wheel.This moved the rear wheel a bit but not much.
So it looks like a bit of newbie fubaring on my part & a bit of disclosure about the diffs by the p/o
This would explain why it seemed to go uphill like a rocket but rev its **** off

Cheers lads, at least I feel there is some light now