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MG MGB GT V8 Factory Originals Technical - Banjo Axle on a V8
|Has any one used a banjo axle on a V8 conversion? Is it strong enough?|
|Not really likely to last. Tried a banjo unit w/a built 3.9 motor, cooked said axle, put a tube assy on there w/3.07 diff and all is well. They're dirt cheap either way, so probably best to just get a tube unit and not worry about it.|
|James I can't say that I've tried a banjo diff but given the cost of a 3.07 gearset and cost of instalation, you might be better off going for a Ford axle. If you're not worried about having an original looking axle then you might find it particularly cheap in the U.S. Find a price for an axle from a wrecking yard and get a quote for shortening/resplining/bolt pattern change etc at a hotrod shop that does machining. I had it done in Australia and it cost around $600 U.S. dollars for the whole thing (I paid $200 for a low mileage LSD axle hence the extra cost).|
The merits of such an axle can be found throughout the archives. HTH
|Before posting this question, there has been discussion on the MGB Tech. board about using an MGA axle (banjo) in an MGB. The discussion centered around a disc brake conversion. It was revealed to me there, that the banjo axle weighed a good 60 lbs less than the the tube. I know that this axle is noisier but I don't think that will matter in a roadster with a throaty V8 exhaust. |
Any way, my thoughts were these:
1. With a 60 lb. weight savings the axle should improve the ride quality of the car. (I am building a 3.5 with low power--about 175 hp at the flywheel. I desire a car with good torque and manners, that feels like a 67 roadster. To that end, I have used a 77 body but converted it to chrome bumpers, and metal dash. It has a mechanical fan on the engine. It uses a 66 wiring harness and the only additional electrical load above a 66 is the use of an electric w/s wash pump. I even have a removable softtop, and no headrests on the seats. A tonneau with no headrest pockets completes the look. I know this sounds crazy, but isn't this why we do this?--to get crazy.)
2. Back to the original thought--The banjo axle would also look period, besides with its seperate aluminum carrier, just be plane neat. Plans are to modify the outer ends to use the later (tube) axle drums and hubs as these parts and the brakes are easier to obtain.
So, here is the latest posting from Jim off of the MGB tech BBS:
"The durability issue with the banjo axle is housing flex, a problem which has plagued Ford drag racers for many years. Not having the rigidity of the center section of the tubed axle, the housing flexes under hard accelleration and causes rapid wear of the ring and pinion. I'm not sure of the exact mechanism of how that happens. Apparently the flexing of the housing forces the carrier flange out of round and moves the pinion relative to the ring gear. Anyway the tried and true fix is to weld internal reinforcements between the carrier flange and the rear of the housing. Sometines you will also see braces welded across the back side of the housing as well. I think before I used an MG banjo axle or an 8" Ford for that matter in a V-8 car I'd add the proper reinforcements."
Looks to me from his comments that if the axle doesn't get too much hp input and is treated nicely, and is modified with bracing---well it just might work.
What are the thoughts of you other crazy folks. BTW, I do not want to use a Ford axle. The idea hear is to keep it MG--well kinda, sorta MG.
|James,Ford rear axles, 8" or 9" are used in many high horespower applications.The instances where a axle brace is needed due to case flex is 700hp and up.This is in drag racing where the shock loads are incredible.Road and stock car racers use the 9" rear unbraced with no ill effects.I seriously doubt any Buick/Rover V8 can put out enough power to flex or break an 8" Ford rear.Are you sure that the rear axle flanges are different on the earlier banjo rear to the later Salisbury rear?Is it worth that much to you to use the earlier axle?I spent over $1700 to put larger brakes on my Sebring "B",and no-one noticed,and they are very visible through the wheels.|
|Well, just a thought.|
This thread was discussed between 12/01/2002 and 13/01/2002
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