Wanted : Crown and pinion

[jurgen10]

Hi, I am searching for a crown and pinion (both fron and rear diffs) with a lower gear ratio than my current 5.33 in the 240GD.

The G currently has a V6 motor in, and is running out of revvs very quickly.

The plan is to replace the Ford V6 with a 300GD motor in order to get it back to a complete mercedes vehicle, but I will still sit with the problem that the ratios in the diffs are too high.

Is there anyone who would be interested in swopping the centre portions, or crownwheel and pinion (maybe someone who needs a G that will only be used offroad for mountain climbing)

[Andrew]

Jurgen, I have done the numbers on the gear ratios - I have it on a spreadsheet - and if you leave the 5.33's in but use 235 85 16 tyres you achieve almost the same thing.

Theoretical revs at 100km/hr:

5.33 diffs with 205R16 tyres = 4159
4.89 diffs with 205 R16 tyres = 3816

5.33 diffs with 235 85 16 tyres = 3537
4.89 diffs with 235 85 16 tyres = 3238 (a 300diesel does not work with this combo in my experience)

Unless your diffs are conjammed why change?

[Pete460332]

I agree with Andrew - the 5.33 diffs are desirable if you want to fit tall than stock tires and/ or you are on the highveld
Peter

[jurgen10]

Thanks for the advise , so what I actually needed to buy on tuesday was bigger tyres than the 245/70/16's

Then I would have solved the problem to some extent.

Will have to start saving again for some 85 profile tyres....

Is there anyone who wants to swop me for my brand new set of 5 Bronco MT tyres for a set of tyres with a higher profile?...hehehe

Eish.

[Dawie Louw]

Speak to the tyre shop, they may be prepared to trade your 'wrong' tyres back - for a small charge.

[jurgen10]

Ok so I got hold of a set of 235/85/16 tyres.
Fitted them and took the G out for a short drive om the High-way yesterday afternoon.
The results are still not what is expected ( I also made some calculations and theoretically I should be doing much lower revvs at 110km/h)

At 110km/h (GPS Speed) My rev counter in the car is reading 5000rpm.
And the car's spedo is reading just about 100km/h.

According to the calculator found here:
http://www.osella.com.au/gear-ratios.htm

I should be doing at least 160 at those revs with a final drive of 0.813 (I have a 5 speed box fitted, but I am not sure if it is an origional G box)

So what is next?

I will be checking the Gearbox to try and figure out which ratio's it has, as well as the CW&P to see if it is in actual fact a 5.33.

[Alan]

How sure are you that the rev counter is giving the correct reading. It does sound very high, too high in fact even with 5.3's.

[jurgen10]

I have no way of knowing if it is in fact the true reading.

The motor does sound if it is going through the sound barrier at that speed, but I will need to get another rev counter if I want to check the accuracy of the one currently in the car.

Could it be that I took the pick-up from the wrong source? I ran a wire directly from the wire that goes from the coil to the distributer ( i.e. the wire that feeds the condensor.)

[Pete460332]

Should be doing ~3300 rpm [at]100 with a 1:1 4th gear , something does not compute.
Peter

[jurgen10]

Yip, I agree. Somehow the figures do not add up.
Further investigation is required.