For my Model A coupe, I'd like to use a 36 Ford Banjo rear, and a 1955, stock, 322 Buick Nailhead. Question #1: Will the Nailhead destroy the rearend, I plan on using 750-16 tires. Question #2: How can I "beef" up the the rearend. Question #3: Where are the weak spots/point on the 36 Banjo, and how do I address the issue. Help a novice Nailhead/Banjo guy. Thanks, Chris
THe weak links would be the axle keys and the non supported pinion gear. You can help the keys buy lapping the hubs to the axle shafts and using hardened keys. This was a trick the Chrismans used in the Hemi powered sedan. Next, the pinion gear will want to climb the ring gear, I think in 1939 or 1940 Ford went to a supported pinion. This helps reduce that concern. Use of thin bias plied tires and not too much clutch engagement can help save the rear. If you never dump the clutch, you should never break the rear with a stock 322.My pops roadster runs a stock 32 rear and box with a solid cam 3x2 265. You can't shift for your life but so far I have not puked the rear on launch either. I am all too sure it WILL happen someday though.
I am sure the smith bros in Idaho could stuff some late model axles into the banjo rear end. Then something else will be the weakest link. Speaking of link, here is the link to the hot rod works in Idaho http://www.hotrodworks.com/index.asp Axle Conversion Kit for Early Ford Brakes Part No: 1103K Price: $850.00 This Kit includes all of the parts and instructions necessary to convert your banjo rear end to modern style axles. Machine work is required and is detailed in the instructions. The kit includes: Axle Gears Bearing adapters and hardware Axle seals Axles with bearings and wheel studs. chuck
Remove the axle key Put some fine lapping compound on the tapered part of the axle. Put the hub on lightly and rotate back and forth Remove the hub and clean off the compound Reinstall the key
My understanding is that you would lap the hubs onto/into the axle stub much like lapping in valves for a good fit. You would remove the key from the axle, use a valve lapping compound, and grind the hub into the axle stub, spinning it until you get a uniform contact area. This will help distribute the load through the axle stub, not just on the key and key way. The Idea is to create as much surface contact as possible. I can't imagine how much time this would take, seems like you could go through an awful lot of beer before the project would be done. I run a Big Olds/Pont rear in my 55 Buick, I don't have a banjo rear. But when I pull pops roadster rear out to change the worn key out, I am going to try this. I might also have a second key way cut into each axle and hub, but the lapping is gonna happen for sure-that is something I can do in the garage, I can't cut key ways at home. (not accurately atleast).
Surprizingly the Nailhead has alot of torque. Ive had a 264, 322, and a 401 and they all have way too much torque. I guess if you are really careful you wont snap the keys or snap an axle, but Id concider a different rear if I were you. Just like very one told me with my banjo...leave the burnouts to the 9"ers
Those engines were designed to move very heavy and large vehicles, hence the cubic ***loads of torque. And as a result, yeah, they'll break puny things. Unpunify your stuff and be mindful of what you're doing when you engage the clutch and you should be OK.
So, let me get this right, the weak spots are, at the outer areas, where the keys are. What about the gears and the cast housing???
If you are not an animal it should hold up. Heck you can break anything if you try hard enough. chuck
FWIW, which probably isn't much, i'm running a '49 ford rear in a model a, with a 52 ford truck trans. (it's like the 39 ford, 3spd toploader, but open driveline). Anyhow, as anyone with one of those knows, they aren't exactly the strongest ******'s. I'm runnin' a 322, 3 deuces, etc. I only had one incident with the ******, a broken tooth off first gear, and i beat the balls off of it at the local dragstrip. If you are determined to use the banjo rear, i would bet you could if you don't beat the piss out of it, regularly anyhow what trans are you running just out of curiosity? if you're running the banjo rear with the closed driveline, you'll probably run a '39 style toploader. That is a "weak point" itself, as stated with the broken tooth. There is quite a bit of slack between gears in first. when you mash it at a stand still, the gear teeth are often not touching and tend to break. if you're moving slightly, meaning the teeth are touching, you're a little safer if you want to lay some rubber. they are pretty simple to rebuild too if you end up breaking teeth, or if the synchro's lock up. if it's a street car and you get on it once in a while, you'll be ok. if you take it to the strip on occasion, you'll probably be ok, if you're going to race it/drive it hard regularly, you probably will break something.
If you get the keys to hold up, the next likely place will be the pinion gear trying to walk up the ring gear. If this happens, you will wipe out the banjo casting where the pinion gear bearing is. Then the gears will chatter and likely break/chip etc... The unit as a whole is weak, if you beef up one area, you will find the next weakest link. As many have said already, it depends on how you drive it. My buddy had a 303 Olds, now has a 324 Olds and has not broken anything, but he drives it a little less agressive than I would. Two projects down the line for me will be a Model A. Not sure of the body yet but the frame and driveline parts are piling up in the garage. I will run a healthy 322 Buick, LaSalle box and likely an early-mid fifties Olds rear. I have the small Olds rear, big Olds rear and 56-up Chevy rear to pick from in the garage, but I think I will use the small Olds. Although the Chevy rear nearly bolts up to 46-48 Ford rear wishbones. Just need to move the holes about 1/8" inch if I recall correctly-it has been a while now since last time.
Wow, I wonder how long my '36 banjo will last with a 330 desoto/727 combo in my "T"modified with 650-16s? My old jeep's amc 20 rear used keyed axles. A pretty commen trick was to tighten the nut as much as possible, then mig the nut down. I'd go for a heavier rear, but I'm a ****er for "wide five"
The V-8 banjo rears have a supported pinion shaft. The "A" banjo's did not have the pilot bearing/supported pinion. Most of the flex in a high torque application comes from the ring gear. It is kind of thin and wants to flex away from the pinion gear when under really high loads. Some racers have welded in an adjustable bronze bushing that will ride against the ring gear on the opposite side of where it meets the pinion. As others have said, if you upgrade the axles, or at least get a proper fit with the hub on the axles and install safety clips, you can have many miles of happy motoring. They are really pretty durable. Ken
if you decide not to use an olds rear, i don't know how common they are, but like i said i used a 49/50 ford rear. The gears were 4.10, 3.90 something, 3.73, and the much sought after 3.54s. If i recall, 49-54 ford third members swap, 52-54? mercs, and i forget what lincolns. The 4.10/3.90 rears were in 3spd manuals w/overdrive cars, and the 3.73 and 3.54 were in the "fordomatic" or "mercomatic" trans. cars. I'm running a 3.73 gear, and it will rip the track up, and you can cruise at 70-75 mph at about 3,000 rpm comfortably. the other positive note is that the width is damn near perfect for the A body. Again, not bullet proof, but cheap, relatively common, and brake parts are pretty cheap.
well, went "ebaying" and found this one for 50 bucks. It's a '56 olds and it appears to have been in a Model A already. Downside (maybe?) is that the gearing is around 3.25. Good cruising gear! number: 160189103391
Ken, thanks for setting me straight. I thought the ring gears were unsupported until about 1939. As I said, I don't run one in either of my cars, so I am no expert. But the safety clips/flanges are a must and dirt cheap I think. I think the cheapy clamp style is about $20-30 or so. Where are the guys mounting the bushing off of? the banjo it self? Sounds like an interesting set up. I'd like to hear more details if you have any.
You drill a hole in the left side axle housing on the front side where the pinion gear meshes with the ring gear. Weld on a threaded bung so the threads are perpendicular to the ring gear. Fab a threaded stud with a bronze pad on one end. Thread the stud in until the bronze pad slightly drags on the ring gear. Install a jam nut. If the ring gear tries to flex, it will ride up against the bronze pad and be supported by it. As it wears, adjust the pad in with the threaded stud and retighten the jam nut. I don't think its necessary for the street, but I've seen it in drag race applications.
Cool idea/setup. I have seen quite a few old drag rears, cut down for slingshots etc... but never noticed any 'bolt/rod' sticking out of the axle tube. SLick little tech piece though. Must add a ton of rigidity to it. Thanks for the info.
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