5 replies to this topic

[lowact]

Hello. Here is pic of our Moke.

Clubman GT engine with close ratio box, 64/17 diff and 13 inch wheels.

Moke aerodynamics limit on-road usefulness of this drive-chain and is a bit too high geared for driving in the bush, which is what we like to do.

So we're thinking of changing the gearbox and diff.

We are imagining that the best we could do would be to fit the wide ratio gears from a Metro HLE into a minispares 5-speed with 65/15 limited slip diff. This would give us the lowest possible 1st gear and 5th gear similar to our current 4th gear.

Please can we have any advice?

Is there any reason why this wouldn't work?

Can anyone suggest, where we might be able to buy a Metro HLE wide ratio gearbox, i.e. with ratios 4.004, 2.307, 1.435, 1.000?

Also, with limited slip diffs, is there any tracking (understeer) issues?

 

Thanks for any help, greatly appreciated.

Regards,

Colin

 

 

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[unburntfuelinthemorning]

What you're proposing sounds feasible.  Speak to Minispares and they can probably have one built to the spec you require.  You may have to wait a while for it though.

[lowact]

Thx. Spoke to Minispares (Gavin King), wasn't good news. Their 5th gear drives off the end of the layshaft. Apparently earlier designs used the existing layshaft however this proved too flimsy, now they use a whole new, beefed-up layshaft. They only make one design of these, i.e. all their helical 5speeds have the same very close gear ratios. Gavin thought that using the Metro HLE gears could probably be done but not by them.

Thinking about it, maybe not by anyone. Power = torque x speed. The Metro HLE box gets its range by slowing down the layshaft, means it carries more torque, therefore it would  be even more prone to fail than a std layshaft in a 5speed close ratio box.

 

I then worked out (interpreted) the ratios. Since the overdrive works off the layshaft, the overdrive ratio = the layshaft drive ratio x the 5th gear ratio. By my calculations, the Metro HLE layshaft drive ratio reduces the speed of this shaft so much that the minispares 5th gear ratio is not enough to achieve an overdrive, i.e. 5th gear would be lower than 4th, to fix this we would need to make our own different ratio 5th gears!

 

Conclusion is, for lots of reasons, our brilliant idea is a total dud.

 

Plan B is to use a std Metro 4speed box and our current 64/17 diff, should give ~20% more torque in 1st gear with the same top gear performance. Plus a limited slip diff.

Means we need to find a Metro HLE gearbox or, at very least, the gears. Can anyone suggest a possible supplier (e.g. specialist UK wrecker) to include in our search?

Thx for any suggestions,

Regards,

Colin.

 

 

[Vinay-RS]

Welcome, good luck with the work that you've got planned.

[unburntfuelinthemorning]

You could try Guessworks.  http://www.guess-works.com/

[Spider]

Hi Colin,

 

Nice Car mate.  We get down your way from time to time on some of our runs.

 

The gear ratios you are thinking of running are what I run in our Mokes, but with your engine, that would be less than ideal and as confirmed by Gav, can't be done with their 5 speed. I'll suggest to you as well that while I see and understand the desire for a 5 speed gearbox, I think you'd find in short order it to be a waste of money in a Moke. Yes, the engine rev and what seems to be 'high' compared to most modern cars, but they are happy doing so and if it's tuned properly, it won't wear out, in fact, fitting gearing that's too tall will wear the engine faster. If you fit a 15/ 62 FD, you'll find that quite a sweet spot.

 

In terms of a Limited slip Diff, you'll find apart form it being 'nervous' to drive that with the (big) 13" wheels of a Moke, you'll be breaking Crown Wheel & Pinions as well as Gearbox Cases too. Your best bet and is very nice to drive with is a Quaife. I run these in all our Minis and Mokes and I'd never go back to an Open Diff. I did try a LSD years back and found it dreadful.