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MGA Final Drive Ratios - RA-201

This is a list of final drive ratios which were available in various cars that will fit in the MGA (and early MGB) banjo type rear axle.

Model Engine Rear Axle Ratio Teeth R/P Max. Brake HP Kerb Weight lbs. Wt/HP Ratio
Austin A55 van, Morris JU and J2 vans ---- 5.125 41/8 -- ---- -----
Austin A10cwt & A15cwt vans, early Sherpa Van ---- x.xxx xx/x -- ---- -----
Morris Cowley 1200 BP12M 5.125 41.8 42 2464 58.67
MG ZA Magnette BP15GA 4.875 39/8 60 2464 41.07
Austin A50 & A55 & Wolseley 15/50 ---- 4.875 39/8 50/55 ---- -----
Morris Oxford series II BP15M 4.875 39/8 50 2464 49.28
Morris Oxford series III low compression BP15ML 4.875 39/8 50 2464 49.28
Morris Oxford series III high compression Morris Oxford series IV BP15MH 4.875 39/8 55 2464 53.11
MG ZB & ZBV Magnette BP15GC 4.556 41/9 68 2464 36.23
Austin A60 pickup (and van) 16AC-16AD 4.556 41/9 61 2200 36.07
Austin A55 mk2, A60 Countryman, Morris Oxford series 5, Morris Oxford Traveller Series 6, Wolseley 15/60 ---- 4.556 41/9 -- ---- -----
MG Magnette mk3 & mk4, Austin A60, Morris Oxford series 6, Riley 4/68 & 4/72, Wolseley 16/60 ---- 4.3 43/10 -- ---- -----
MGA 1500 Tourer, early BP15GB 4.3 *1 43/10 68 1988 29.23
MGA 1500 Coupé, early BP15GB 4.3 *1 43/10 68 2015 29.63
MGA 1500 Tourer 15GB-15GD 4.3 *1 43/10 72 1988 27.61
MGA 1500 Coupé 15GB-15GD 4.3 *1 43/10 72 2015 27.99
MGA Twin Cam Tourer 16G-16GB 4.3 *2 43/10 108 2185 20.23
MGA Twin Cam Coupé 16G-16GB 4.3 *2 43/10 108 2245 20.79
MGA Twin Cam Tourer, late 16GB 4.3 *2 43/10 100 2185 21.85
MGA Twin Cam Coupé, late 16GB 4.3 *2 43/10 100 2245 22.45
MGA 1600 Tourer 16GA 4.3 *1 43/10 79.5 2016 25.36
MGA 1600 Coupé 16GA 4.3 *1 43/10 79.5 2075 26.10
Lotus Elite (C-C) 4.222 *6 38/9 83 1455 17.53
MGA 1600 Mk.II Tourer, High Compression 16GC 4.1 41/10 90 2016 22.40
MGA 1600 Mk.II Coupé, High Compression 16GC 4.1 41/10 90 2075 23.05
MGA 1600 Mk.II Tourer, Low Compression 16GC 4.1 41/10 85 2016 23.72
MGA 1600 Mk.II Coupé, Low Compression 16GC 4.1 41/10 85 2075 24.41
MGB Tourer 1962-1967 18G-18GB 3.909 *3 43/11 95 2030 21.37
Wolseley 6/80 - 1948-1954 22? 3.909 *5 43/11 72 25cwt -----
Wolseley 24/80 - 1962-1967 24? 3.909 43/11 80 25cwt -----
New manufacture special
www.autogear.co.uk part no. CWP033
(Courtesy of the Wayback Machine)
New web site: www.autogear.uk.com
Available from Basil Adams in CA, USA
---- 3.7 37/10 -- ---- -----
MGA at Le Mans in 1955 1500 3.308 *4 43/13 -- ---- -----
‘B’-Series engines and banjo-style rear axles were used for all MG ZA, ZB, MGA, and early MGB

*1 Optional gear set: 4.556
*2 Optional gear set: 4.875
*3 Optional overdrive on later models, final drive including OD = 3.14
*4 Limited production 43/13 gearing from 1955, very rare. See next page
*5 The Wolseley 6/80, came 5 years before the ZA Magnette, and 7 years before the MGA. Casting number on the dfferential is ATB7009 (others listed here are ATB7182). It should be noted that the earlier assembly has a seal on the input shaft with smaller OD, which might imply smaller bearings on the input shaft. This differential does however bolt into the MGA rear axle. You may expect to find an outline of Australia circling the MOWOG on the casting, indicating that this was made in Australia. Peter Baldry from the MGCC Sydney relates that this differeitial is from the 24/80 Wolseley, that the only mod needed is to change the sun gears to take the half shafts, and the pinion seal size is 2.385" OD.
*6 The UK MG owners club can supply them, but of unknown quality. Also Heathrow Transmisions, who get theirs from Italy, so they might be OK.

Addendum April 2011:
Newly-manufactured crownwheel and pinion gearsets for the Hardy-Spicer banjo-type rear axle (Austin B-series axle) of the MGA and early MGB Roadster are currently available in:
    3.700:1 - available from Autogear, Part # CWP033
    3.909:1 - available from Moss Motors, Part # 267-165. and Autogear, Part # CWP034
    4.100:1 - available from SC Parts Group and Cambridge Motor Sports
    4.222:1 - available from the UK MG owners club (may be questionable quality)
    4.222:1 - available from Heathrow Transmisions (who get theirs from Italy)
    4.300:1 - available from SC Parts Group and Cambridge Motor Sports
    4.556:1 - available from Moss Motors, Part #267-185, and Cambridge Motor Sports
    4.875:1 - available from Victoria British, Part # 5-1049

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