Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Gearing

Hi all I have a question.
I have been thinking of re gearing to 4:10 as recommended by many on the 4/4 Sport but would like to feel what it's like to drive..So I have just swopped over to some spare wheels I have in the garage on to the rear which are shod with 205/60/15 and a circumference of 1948mm.

Now my 4/4 sport with stock 3:73 gears and rear tyres Conti connect 165/80/15 which have a circumference of 2012mm.

Now how close with the 205's on is this to re-gearing to 4:10 when running on the stock 4/4sport gearing @ 3:73 ?



Cain

Approx 2.8% reduction according to tyre size comparison site.
http://www.tyresave.co.uk/tyresize.html
http://www.miata.net/garage/tirecalcold.html

My rough calc on the diff indicates 7.24% reduction, so nowhere near close enough to give a true feel.

Although no guarantees the maths are right!!

4.1 / 3.73 = 1.099 which is a 10% difference,
2012 / 1948 = 1.032 which is a 3% difference,
so I think you have a long way to go!
Maths is bit suspect, Dave, I hope you're not an accountant!

Thank you all.
I guess it will be suck it and see..
So has anyone found out were to get aftermarket ring and pinions for the BTR axle?
is it available as a land rover R&P?
How about LSD's what is available aftermarket?


This is a job I would like to do myself along with the LSD

Cain

If you want an aftermarket LSD, then a very sensible choice is the Quaife ATB helical-gear LSD. It doesn't lock up like the plate diffs, and so it won't spit you off the road in extreme conditions.

The unit is available for about 650 quid. If it's any guide, I recently got Billy Bellinger to rebuild my Salisbury axle with a Quaife ATB and 4.1:1 final ratio, with new bearings and everything, and it worked out about 1500 quid. Highly recommended.

Gosh your brave, axle rebuilds are all about pre-loads and backlash Land Rover stuff won't fit BTR axle, I think Bellingers advertise in Miscellany who may be able to help. The 4:1 in my 4/4 was a factory fit and Jays on this forum had his done at Mog dealer Mike Duncan

I've re-geared and ARB'd AMC 20 axles and Dana 44, both basically the same as the Dana 60/ Salisbury, shims dial gauges and engineers ink to check the work in out in out in out till its' all correct. My last set of racing axles were 9"Ford hybrid 3rd member no skims nice.
But that was all about 15 years ago.
I was kind of looking forward to the challenge!!
Cain

I take my hat off to you

Having rebuilt a BMW airhead Boxer gearbox, including reshimming,a few years ago, I take my hat off too!

Jays
I've done that one too with HPN gears 1st and 5th on two of our overland R100GS"s, Still got them and a R100RS, R100CS, HP2E, and a R100GS mono HPN replica in bits. 70's 650 Bonnie in bits, DR350 and Yam 600 Fazer.

I love building toys!!! and to be fair so does Michele she even has her own Snap on box and tools, hydraulic work bench and was once a aircraft mechanic time served.
Nothing like having a woman that appreciate a diff on the kitchen table in winter, and a line of Bikes in the dinning room on their own benches!!!