I thought it was tradition too. Also that someone measured it many years ago. Didn’t spot it in rave. Thanks both.
Well yer probably wondering why I is asking… I have measured my ratio. Reason being I’ve been looking into VCU running temps v tyres v speed v time etc. This got me wondering about the drive ratio we’ve talked about for many years. While checking me timings for the one wheel up test I thought I’d have a go. My method was:
- Chock one front wheel.
- Release handbrake and put in neutral.
- Left opposite front wheel and the rear on the same side and support on axle stands.
- Slowly but firmly turn the front wheel forwards to take up the slack in the transmission (ird and rear diff) and watch for the rear wheel to turn. Remove pressure slowly so as not to put any slack in the transmission by the rear wheel continuing when the front wheel stops.
- Put masking tape on both prop shafts to see if they’re still inline and the vcu int slipping.
- Put masking tape on the bottom of both lifted wheels, on the side wall, directly below drive shaft centre.
- Now turn the front wheel while trying to keep the speed constant so as not to jar the vcu and cause it to slip too much (it shouldn’t). Turn the wheel 20 full revolutions and stop by slowing down slowly so you don’t put any slack in the transmission by the rear wheel running on further when the front wheel stops.
- Now check the 2 props are in alignment and if not correct with 2 screw drivers through the UJ’s. If they were out, then turn the front wheel 90 degrees backwards, then turn forwards slowly 90 degrees to take out the slack, whilst removing slowing down slowly so yer dun’t put anymore slack back.
- Now look at the rear wheel to see where the tape mark is. 20 revolutions is enough to see if the rear wheel turns faster or slower than the front wheels.
- Now repeat the 20 revolutions cycle until the rear wheel is offset from the front wheel by a factor you can easily measure.
To be honest the vcu was only out by nearly the width of standard masking tape, during the whole test I did. So it won’t be out by much after 20 revolutions. Or I would expect this to be the case at least.
I then continued the above test in stages of 20 revolutions of the front wheel, until the rear wheel was out by half a full turn. Near the end I drop the number of revs before checking each time. You can see when your close. Then I did me maths to see what the difference was. That’s the puzzling bit. I don’t get 0.8% and can’t see why. I’d doubled my figures to change them from half a full turn out to one full turn out, and doubled the revolutions too. So I now know how many turns of the front wheel, will result in the number of turns of the rear wheel. Also I know what my Freelander % ratio is.
If x = front wheel and y = rear wheel then
x = y – 1 or x = y + 1 (for the maths peeps)
Now yer probably wondering why I int told yer me result of the number of turns, and if I found the front wheel to turn greater or fewer turns, when compared to the rear wheel, during the test. That’s because I’d like someone else to offer to do the same test. Then we can compare results. I know this may seem a bit mad, but you int seen nothing yet.
EDIT: Please PM me the results so we can discuss them before posting online. We may need a 3rd person to perform the test too. The only way to know for sure if someone has done the test is for them to provide results first without knowing our results beforehand.
The problem could be mine is a v6 and the ratio is different. Or mine has something non standard fitted causing the ratio to be different. Or the figure of 0.8% is incorrect. My Freelander is a 2001 v6. It would be good if someone with a v6 or td4 followed the above test to help me with this experiment. Earlier Freelanders were said to have different ratio’s in the IRD or rear diff or something… So it would be nice to compare some of your results too, if some of you would like to also follow the above test.
