Destroyed my 3.70 Equi-Loc

[JimNolan]

Well, I did it again. The Yukon axles came in. They are nice. I'll cut them in the next couple days. My buddy has a machine shop. I got a problem though. The axles have the wrong BRAKE OFFSET. I didn't know there was such a thing until I started looking at where the bearings were going to sit. Seems Ford made more than just the big bearing 9" axle or the small bearing axle with just different lengths. They made different offsets to accomodate different size brake shoes. They made 2", 2.125", 2.375, 2.5" and 2.66". And, each axle has a different offset ( distance from the outside flange to where bearing sits. Well, to make a long story short I called Yukon and they said go ahead and turn the collar down to what my specifications called for. They don't make a brake offset to fit every size brake shoe. The axles they sent me were 2.375" offset and I need 2.125" offset for 1 3/4" brake linings. They make different brake drums for different brake linings also.
   I can cut them but wondered about the intergrity of the axle by cutting on it. They told me to call the guy that ordered it and send them back if I didnt' like them. They said the warranty would still be 5 yrs on the axle but he declined to send me a Email to confirm what he'd said.
   Question is:  Have any of you guys had to cut an axle to obtain correct brake offset. Or, is this why you order custom axles to begin with. Jim

[hogwagon]

 As we already know all parts will be modified to fit so if you have a qualified shop that can do it I would go for it. We own a small Harley aftermarket shop and have a mill and lathe mostly for the bolt on parts we have to install. As for axles I have used Moser's but on a different car so can't honestly compare. I have been rough on them with no known problems and piece of mind over stock. I too have broken a few parts usually late at night not near the house or shop.

[Hoosier Hurricane]

Jim:

If you didn't have a buddy with a machine shop, you would have to spend enough to make the Yukon axles work that the price would have probably been about the same as Moser.  I ordered my Mosers for a '57 Ford with 31 splines and they fit like stockers.  2 days after I ordered them they were on my doorstep.

John

[JimNolan]

John,
   You're right as rain. Some people will never learn. I'm beginning to think I'm one of those people. When I contacted Just-Rear-Ends and Moser I asked for an estimate on the pig and axles. Both came back about the same @ $1695.00 counting shipping. The pig and axles from R-Mustangs came in at $1324.00 counting shipping, buying wheel lugs and bearings.
   I think what made me go with the set-up I'm getting is the $371.00 I saved getting what I did. But, there's a little voice in the back of my mind telling me I'm not as confident in this setup as I would be with Moser. If I'd have known I had to cut the bearing seat back another .187" I sure wouldn't have went with Yukon axles. But, I do have a good machinest with the equipment to do this. If I didn't have him, I'd send them back. He's got the hanger next to mine and we're helping each other all the time anyway. Jim
PS  For anyone thinking about getting axles to fit a 57 Ford with 1 3/4" inch brake shoes the distance from the face of the axle flange to the seat of the bearing (Brake Offset) is 2.187". The drivers side axle length from the face of the flange to the end of the axle is 26.000". The length of the passenger side axle is 30.375". That's if you have a 52.000" housing.
 

[JPotter57]

Same as John, I ordered Mosers for `57, with the short offset.  That offset is also why later OEM disk brakes wont work on the `57 rear without some work.  They bolt up but offset is wrong..I found that out the hard way too.

[JimNolan]

There's something I want to ask you guys while I've got you on the phone. Question:  300 hp in a 3900 lb car shouldn't break an axle should it. Wouldn't you think after 54 years the axle was weak to begin with. I'd have thought I'd have broken a universal joint first. Jim

[shopratwoody]

Probably age. When I raced, aftermarket axles were mandatory. And no, I don't think 300hp
should break it either. Must be the stick shift.

[JPotter57]

It would be more the torque that broke ir than hp.  It may only have 300 hp but it might have 400 or better lbs ft of torque, more than enough to kill a stock 28 spline axle with a manual trans.  I'd say that the lower 1st gear in that Tremec might have something to do with that also.  Toploader has a 2.78 1st gear, I think the Tremec has a 3.something...more mechanical leverage equals more stress.  Plus the age...

[F570RD]

Now is your chance to put bigger brakes on the car.70's full size wagon is what I used....One of the setups I had in the 80's was using 8"-28 out of a Cougar and machining the bearing shoulder back .250" and it worked fine.The original axles look like they were made in a black smiths shop.These worked well racing the car with 1.60 60ft times.When I went to bigger brakes I then went with Moser 31's.Those are gone and now am in a 35 spline world......ahhhh the evolution of our cars

[JimNolan]

I googled " how to calculate rear wheel torque" I was very surprised when I figured out the torque on the rear wheels if the tires don't spin. The formula is: RearWheelTorque = Engine torque (figure highest) times Transmission Ratio times Differential Ratio. My car's rear wheel torque came out to: 427 (@ 2800 rpm) times 2.87 times 3.70 = 4,534 ft lbs torque. Jim

57Ford,
  I already had bought new brakes before the axles came in. Also, I would have had to find new drums.

[Hoosier Hurricane]

Jim:

Interesting that you find the left axle is 26".  That's what I measured mine when I called Moser.  They called me back and asked if I had modified something, their records show the axle to be 26 1/4.  How's that for service?  I dont' think 1/4 inch would not be enough difference to matter in that application.

[JimNolan]

OH contrare great white legend from Indiana. 1/4" would make a big difference expecially on my differential. Where mine broke was right at the spline teeth. There's 1 3/4" of spline and that's what was left in the differential. I haven't measured the length of the differential seat but if my axle had been 26 1/4" long with 1 3/4" of that in splines, I'd have been trying to push 1/4" of unsplined axle into the differential. A 26 1/4" axle with 2" of spline on the end would work.
   This axle I got from Yukon says the axle can be used for lengths 25.5" - 32.87". I measured the shaft and found out that if I cut the length for a 25.5" axle, I'd have 1 3/4" of spline left to go into the differential. 1 3/4" must be the magic number for amount of spline you need. Jim 

[Zapato]

only axle I ever broke was in my high school daily driver 57 with a 66 GT 390, broke it twice. Finally figured had a slightly bent housing that put things in a bind. swapped in another and almost immediately broke a u-joint. the fun of building on a kids budget with junkyard parts. not to be overlooked in the formula was the simultaneous rush of testerone on a 16 year old boy every time he fired it up and its instant effect on his right foot.

Zap-

[JimNolan]

John,
   After spending the morning making sure I wasn't contradicting something you said and I end up wrong. My housing was 53" exactly from housing flange to housing flange. The bearing offset was 2.1975" for the axle using 1.750" brake shoes. This axle uses the RW207CCRA small inclosed bearing.
Drivers side axle:
   The spline itself is 1.437" long. Of which .093" is not inserted in the differential splined receptical. The differential splined receptical is 1.125" deep. The end of the axle has .219" protruding through the differential splined receptical. Thus, if you added another 1/4" to the length of the axle, it better be splined or you would be trying to insert .157" of unsplined axle into the differential receptical.
Passenger Side Axle: 
    This one was a little different. It had .375" of splined axle that wasn't inserted into the differential receptical. It's total length was 30.416" long with about the same length of splined area at the end of the axle as the drivers side had. I didn't measure it's receptical depth.
   I know this sounds like hogwash to some people but if I had had this information last week I'd have a set of custom axles sitting here from Moser already. And I would have known that one axle don't fit all ( I have found out more than I ever wanted to know about 57 Ford axles ).  Jim PS. The original 57 Ford axle had to withstand 2800 ft. lbs of torque with a 3.70 rear gear and manual transmission. I was putting 4500 ft lbs of torque on it. Something to think about when you slap a bigger engine in your car and keep the original rear end.

[Jeff Norwell]

 The original 57 Ford axle had to withstand 2800 ft. lbs of torque with a 3.70 rear gear and manual transmission. I was putting 4500 ft lbs of torque on it. Something to think about when you slap a bigger engine in your car and keep the original rear end.
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That is very good to know Jim.