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MGA MGA vs MGB rear axles and differentials

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I figger you've got a 3.9 if you followed that guide. Well done!


...see?!?! Wazzant simple? :laugh:
 
All will be reveal'd... as long as yer chalk's DRY. :smirk:
 
3.9 pretty standard for MGB's.
 
Yup. Not a lot of "math" involved for this. :thumbsup:
 
tdskip said:
Check me to see if I got this right, as a Salisburg axle it would have been used on later cars, starting with the BGT right? Did the ratios vary in Salisburg axle or where they constant through the production run (can't imagine they were constant)?
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Tube axles were installed on all cars starting in 1966 and were unchanged throughout the end of production. Ratios for all MGBs 1962-1980 was 3.9:1. Only the axle changed, never the gearing. The gears themselves are not interchangeable between banjo and tube.

tdskip said:
Do you know off hand what a stock MGA would have been?
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4.1 and 4.3 were standard for MGA.
 
Thanks Steve.

So - hypothetically speaking will a Salisbury axle bolt right up to an MGA, and what would the benefit be of doing so? Slightly fewer RPM at speed?
 
tony barnhill said:
3.9 pretty standard for MGB's.
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Only ratio ever offered on MGBs form the factory, banjo, tube axle or other wise, as mentioned there are few ratios avaialble form the MGC nad MGV8s for the tube axle housing. The in the Banjo rear ends, same thing only the 3.9 was offered but there are other diffs ratio available form the MGA and other Brit cars that used the same rear housing, alot of them use different inboard splines on the axle, so some of these ratio you have to install MGB spider gears to match the MGB splione count on the axles. Some earlier MGA and such diffs are set up for the fine spline, but always check to be sure.
 
Tom, I believe the spring perches will need to be relocated but otherwise it will bolt in. The tube axle is quite a bit heavier and more difficult to service, so given the choice I'd stick with a banjo for an MGA. The only advantages of a tube axle are durability and less gear noise, neither in my opinion important for an MGA.
 
Believe the tube axle was under MGB's until the 1968 model when they switched to Salisbury.


There are differences in some of the locating hangers for things like bump straps, brake lines, etc...but, if you have the old rear end & the new`one side-by-side you can see the differences & cut & weld as necessary.
 
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