Register now to get rid of these ads!

Technical Just how strong is a Stock Banjo Rear End?

Discussion in 'The Hokey Ass Message Board' started by poboyross, Jun 27, 2016.

  1. poboyross
    Joined: Apr 29, 2009
    Posts: 2,142

    poboyross
    Member
    from West TN

    I'm having my 8BA rebuilt to mostly stock here in Burbank, and I want to run a banjo rear end behind it. I know that finding the 41 and up open drive rears is ideal, but can an earlier rear end, say 32-40, handle that mild Flathead? I have a 72 Ford 3 speed Toploader that I converted to top shift using the Jeep shift tower, so it will have to be converted to open drive even if it didn't start life that way.

    I used a Ford 8" behind my SBC in my first A build, but for this 34 RPU, I want it to look traditional.
     
  2. theHIGHLANDER
    Joined: Jun 3, 2005
    Posts: 10,413

    theHIGHLANDER
    Member

    The axle keys are the weak link, but only if you plan to lean on it really hard or burn rubber. Some banjos ran 6 figure miles without fail, and ol Henry felt it was tough enough to haul those heavy Zephyrs around. Some may have more direct experiences to share but on hot rods I've always found that you can shear keys by playing too much or too often.
     
  3. AVater
    Joined: Dec 9, 2008
    Posts: 3,318

    AVater
    ALLIANCE MEMBER
    1. Connecticut HAMB'ers

    I've seen some old dragsters using them with shortened axles but me myself have had two broken axles behind an 8BA in different rears and not being abused. Tells me the center section is stronger than the axles but I guess"stuff" happens with 80 year old equipment.
     
  4. Flathead Dave
    Joined: Mar 21, 2014
    Posts: 4,008

    Flathead Dave
    ALLIANCE MEMBER
    from So. Cal.

    What are they charging you for the rebuild? Sorry, i know nothing about the banjo rear ends.

    Sent from my SM-G930T using H.A.M.B. mobile app
     
  5. flatford39
    Joined: Dec 3, 2006
    Posts: 2,799

    flatford39
    Member

    Henry seemed to think so.....Your not doing anything unusual from what Henry let drive off the assembly line.
     
  6. AVater
    Joined: Dec 9, 2008
    Posts: 3,318

    AVater
    ALLIANCE MEMBER
    1. Connecticut HAMB'ers

    To rebuild the rear, I provided the gaskets, seals and axles. The shop charged me an hour's labor to install the axle and provide proper load adjustment. Seemed reasonable to me at the time.
     
  7. That center nut on the axle end is never tightened down enough by those unfamiliar with these axles, 250+ ft/lbs keeps the friction between the tapered mating surfaces and prevents the drum from rocking back and forth on the key, causing eventual failure. Surfaces need to be clean, dry and no flash rust on them. Brake drum retainers are cheap insurance.
     
    AVater likes this.
  8. gimpyshotrods
    Joined: May 20, 2009
    Posts: 24,035

    gimpyshotrods
    ALLIANCE MEMBER

    Yeah, but you sometimes have to re-work those drum retainers, so they don't squeal like hell when I am riding on the crossmember.[emoji6]
     
    Jet96 likes this.
  9. AVater
    Joined: Dec 9, 2008
    Posts: 3,318

    AVater
    ALLIANCE MEMBER
    1. Connecticut HAMB'ers

    Pocket Nick, You're right re torquing those nuts. After you get it all together and run it a while you should retorque as well. Hopefully I have it right.
     
  10. This is far from the first thread on this subject, and I seem to remember from many years ago when this was discussed, the tightness of the taper and re-torquing is very important as Pocket Nick says.

    It was also suggested by a few guys that not only is the quality and tightness important, lapping in the tapers also helps make sure the mating surface is right.
     
    117harv, Texas Webb, AVater and 3 others like this.
  11. clem
    Joined: Dec 20, 2006
    Posts: 4,449

    clem
    Member

    Ive had an 8ba in my '32 - standard rear - for years, '39 3 speed, no problems, - but I'm not a hoon.
    Would depend on how you drive !
     
  12. mrspeedyt
    Joined: Sep 26, 2009
    Posts: 1,029

    mrspeedyt
    Member

    suppose you drive like grandma.
    (that ain't no fun).
     
  13. rusty rocket
    Joined: Oct 30, 2011
    Posts: 5,201

    rusty rocket
    Member

    Years ago I had Wilson welding make me a Speed Demon quick change from a 39 center section. When I contact Wilson welding about the project his first question was what are you going to put in front of this thing. My answer was a flat head, his response was ok we can talk now. So long story short you will be just fine running a banjo behind your Flatty.
     
  14. alchemy
    Joined: Sep 27, 2002
    Posts: 21,770

    alchemy
    Member

    Not sure if I interpreted your initial post correctly, but do you think the pickup rears with open drive are stronger? They are not. Other than some spline counts and some distance measurements, the banjo rears are pretty much the same design and strength from later 1932 through 1948.
     
  15. My best friend in high school in the 60s and best man in my wedding had a '40 Ford pickup with a 289 and real Indy WIDE rear tires (not DOT approve I assure you!) and he twisted axles nearly every weekend! Constantly replacing axles which is a total bear on those rears. Oh, and blowing up stock early Ford trannys too. If you want performance but keep the old look you could consider converting the rear to modern Ford 9" rear axles. Benefit is you gain a modern bolt pattern giving a wider choice of custom wheels. I did the conversion on my Mysterion clone and it wasn't too terrible.
     
  16. Barn Find
    Joined: Feb 2, 2013
    Posts: 2,312

    Barn Find
    Member
    from Missouri

    Henry designed the key to be easily replaceable when duty exceeded the capacity of the axle.

    I busted the keyway out of a Model A axle with a worn out banger. I was abusing it trying to get out of a mud hole and it was not likely put together with the fitted taper and clean and properly torqued nut.
     
  17. Well '32-40 Fords had a mild flathead in them stock. :rolleyes:
     
    TheTumbleweeds and Jet96 like this.
  18. Andy
    Joined: Nov 17, 2002
    Posts: 5,267

    Andy
    Member

    I have only seen 4.11 gears in the open banjo rears. The pass gears are different. I would get a pass center section and put a conversion kit on it. The higher the gear you put in it will be easier on the shafts. A 3.54-3.25 would let you cruse. Get a 35-48 center section.
     
  19. We busted an axle shaft on our 48 banjo. Running a stock flathead. Broke just inboard of the taper area.
    Broke a tooth on the ring gear too at another time.

    When we rebuilt it, took each axle shaft mounted vertical in the vise and, by hand, lapped each hub with compound. Got it all back together with proper shims and such. And ya got to really stand on that axle nut - pretty scary. We went for specs and our torque wrench didn't even go that high! Had to borrow one....

    So far so good, See pics below...
     
  20. Even a 9" Ford or a Spicer 60 will break if its too loose. Any rear you use has to be up to par if you expect it to perform up to par.
     
  21. steel rebel
    Joined: Jun 14, 2006
    Posts: 3,604

    steel rebel
    Member Emeritus

    Don't run a banjo unless you just "HAVE TO HAVE ONE". Many cheaper and better differentials out there now. If you are kicking around the idea make your decision the one using the newer better one and leave all those old parts for us that "JUST HAVE TO HAVE ONE"

    Gary

    DSCN0006.jpg
     
  22. poboyross
    Joined: Apr 29, 2009
    Posts: 2,142

    poboyross
    Member
    from West TN

    Yeah, I get that....but since I would be converting any banjo rear to an open drive, I was curious as to what extra stresses might be placed on an earlier banjo with the open drive mod behind my 8BA VS. an original open drive rear banjo from a truck. Until this post, I didn't know that they were all structurally the same.
     
  23. alchemy
    Joined: Sep 27, 2002
    Posts: 21,770

    alchemy
    Member

    The way you locate the rearend could play a huge part in the strength of the axle housing. If you use a split wishbone system you will likely cause cracks and leakage. I'd suggest a wishbone system with a single locating point like Henry did.
     
    Texas Webb likes this.
  24. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,681

    Bruce Lancaster
    Member Emeritus

    Look at a few early '60's magazines... dragsters ran banjos into the 8's. Mostly aluminum Quickchanges, likely weaker than stock banjo since aluminum. If you study the pics you will see that some were running Ford axles, some had the chassis engineering safety hubs, maybe some had the Merc/Lincoln axles. There were only two dragster rears then, and Halibrand drilled the dragster wheels for both: early Ford and Oldsmobile. If keys go, they are too loose.
    Onliest real difference between open and closed banjo is that the pinions have different splinage to hook up to shaft or to a U-joint. On repairs, if it comes to that, axle change is way easier than a full rebuild because all you have to do to maintain settings is to replace the side gaskets with the same thickness...which should almost always prove to be the standard .010 crushed maybe to 009. Small smallblock, no super tires, try not to do anything with the clutch that would really annoy your father.
    Ideal SBC build for this rear would be to replicate the general character of a hipo 283 Vette...fairly radical cam, plenty of carburetion, poor and ragged low end torque then plenty of steam as you rev it up. In other words, it will be a lot happier with a 300 HP 283 than a 300 HP 350.
     
    HemiDeuce and kidcampbell71 like this.

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.