VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc Why do I keep breaking rear Axles?

1947 Stylemaster. 235 3spd column shift. Stock Rearend/Torque Tube. This is the second Rear Axle I've broken in 4,000 miles. What is going on? Are they known for this, or do I possibly have something that is out of tolerance?

They are not known for breaking. Sounds like you may have a bent housing.

Although I haven't pulled it apart yet, I recall the sound and the feel of the previous time it broke, and it is spot on. I am hoping it is the other side, which may suggest old fatigued parts, instead of a chronic problem. I was lucky this time. It broke in my alley, about 20 feet from my garage.

If it is the same side,better check for a bent housing on that side. Maybe the car was in a wreck and hit on that side.

When I tore out the interior this summer, I found that it was struck on the Passenger side. They arc welded in a new door post and the panel in front of the rear fender. A friend who builds Old Chevy Trucks said that the whole torque tube assembly from a 3/4 truck of the same vintage would fit right in, and have stronger axles, but he wasn't able to provide me with any concrete information.

There is no way a 3/4 ton truck drive linne would work. First the torque tube is a completely different set-up. The differential is MUCH larger and you would be stuck with 4.55 gearing. Also would require larger tuck wheels.
A 1/2 ton is much smalle and still very different.
The 1937 and up were not known for breaking axle shafts. There is some other kind of problem.

Thanks Gene. That is what I suspected. I don't particularly drive the car hard. It rarely sees the high side of 40, as my tires are 60 years old. When I tear into in today, I will first verify that it is indeed an axle, and after that, I don't know what to do. How do I check to see if the axle tubes are true? I can easily test for out of round tolerances, but as far as the rear end being straight I'm stumped.

Otherwise, I haven't had a lick of trouble with it in almost 2 years. Which is why I haven't been on in awhile. No News is good news.I Refinished the interior this past summer with hardwood and leather. Not factory spec, but I used only materials that were available at the time the vehicle was built. I drove from Waterloo Wisconsin to Rockford Illinois last year. Got 27mpg. https://www.facebook.com/photo.php?...8.100000326707852&type=3&theater

[img:center]https://www.facebook.com/photo.php?...8.100000326707852&type=1&theater[/img]


I just tore it down, and it is the passenger side of the vehicle this time. Both axles have broken near the differential. Is this telling me something?

Close examination of the afflicted area reveals that there are cracks that look pretty old. Discoloration and rounded edges are the dead giveaway. If it were fresh cracks/damage I suspect the edges would be sharp and clean.

Is the rear end real loose? Lots of backlash? Worn spider gears?

What year vehicle are you talking about?

Inside the axle housings and differential case, it is particularly clean. I've never noticed any slop or noise from the rear end. (No Whines, No Grinds) There weren't any gnaw marks on the teeth of the gears. I am beginning to suspect that I own a vehicle that was driven by a teenager or a woman years ago. Both of the axles were evidently cracked for a long time. It was probably some kids first car back in the late 60's or early 70's and they needed to burn the tires off. And the only way that's possible with a car like this is to roll backwards and slam the clutch out...

Back Roads- It's a '47 Stylemaster.

FWIW, my first car was a '41 MD TS at 16. Traded for a '47 SD club coupe a year later. Both were driven unmercifully. If breaking axles was a problem, believe me, I would have broken several. 'Never broke the first one. I don't think the little 216's had enough touque to break an axle (although I tried).

Well, for what it's worth, all my friend think that these axles broke because my 235 makes too much torque for the drivetrain hahaha

Sorry for your trouble, but I think its good to rule out bigger problems. If your other axle broke, and this one had old stress cracks...I'd say you're okay.

If you need another axle , they're out there and not too far from you. Good luck getting it back up & running and cool facebook page and photo that you shared a while ago. Keep that '47 rolling! Its a clean machine.

I've found one from a Gent in Oregon State. Chev's of the 40's recommended them. Hundred Bucks. I'm happy. Thank you for the Compliment Daryl.

Originally Posted by stylemaster47

Well, for what it's worth, all my friend think that these axles broke because my 235 makes too much torque for the drivetrain hahaha

I've put thousands of miles on my '37 with a 1962 235cid engine in it and have never had a problem. I don't "baby" it, either.

I am glad somebody else doesn't baby theirs. I don't flog it either, but it is a car, and it is meant to be driven.