BritishV8 Forum

General Category => MG Sports Cars => Topic started by: Phillip G on March 18, 2008, 09:56:43 AM

Title: MG B banjo housing final drive
Post by: Phillip G on March 18, 2008, 09:56:43 AM
Guys,

The most common final drive (differential) on the B's, with the banjo housing rear end unit, is the 3.90 ratio - Right ?

Did MOWOG/Austin ever make a lower ratio - a 3.35 or a 3.09 ratio differential ?  Maybe for an Austin taxicab, or something  ?

I need a better final drive than a 3.90 in my banjo housing B rear end unit.

Any suggestions ?

Phillip G
Title: Re: MG B banjo housing final drive
Post by: Bill Young on March 18, 2008, 03:09:40 PM
Some time back I found this article and marked it. http://www.mgcars.org.uk/mgcc/sf/sf100104.htm  Seems to be a typo in refering to the banjo type axle, I believe they mistakenly used a caption from the earlier T series axle as being in two halves but the list of ratios and other applications seems correct. Doesn't look like there's anything you can use. Disregard the Midget listings, although a similar design the gears are not interchangable. The only option that I see was a listed 3.7 which was an optional ratio for the competition MGAs and Twin Cams but those would be nearly impossible to find I'd think. The most common solution is to replace the entire rear axle assembly with one from a later car with a better selection of ratios. Another possibility would be to install the later MGB tube type axle and get the 3.07 gears from an MGC which will fit that carrier and housing. I've been doing some preliminary measurments to see if the entire center section from a GM 10 bolt unit could be installed on the B axle tubes (tube type axle only) to give the entire range of ratios for the GM axle and still keep the MG brakes and wire wheel hubs for my car.
Title: Re: MG B banjo housing final drive
Post by: Phillip G on March 18, 2008, 04:28:07 PM
V6Midget,

Thank you.  I, too, have marked that article as a favorite !  Great Info !

Phillip G
Title: Re: MG B banjo housing final drive
Post by: Phillip G on March 27, 2008, 10:11:13 PM
Bill,

The 3.07 final drive - locked - would be the answer for the intitial effort.  If you run into such a ratio, please let me know.

In the mean while, I will be using a 3.90 MGB locked banjo rear axle with a Firebird T5 and the Rover 3.5 V8.  Next year we would like to use a better quickchange rear end unit.  

Bill, you know, that is why some cars run much faster than other cars at SCCA races.  Years of developments, changes and improvements make the race cars go faster.

Wish us luck with our MG RV8 in GT2 at Heartland Park and MAM.

Phillip G
Title: Re: MG B banjo housing final drive
Post by: Phillip G on April 21, 2008, 09:43:58 PM
Bill,

I saw a 3.07 final drive offered for sale the other day - the differential for the MG B banjo housing rear axle.

Asking price was 1,800 GBP - $3600.00 US.

Some British parts are now "unobtanium".

I'm still looking for a standard 3.90.

Phillip G