Well Friends,
There is good news and there is bad news. More like sick on the stomach news!! My son and I have been restoring his 72 swinger and finally got it on the road about a 2 weeks ago. Boy it looked great and it appeared to run real strong. Since we installed an 8 3/4 rear with posi, I took it out and pulled some real nice holeshots just to check out the posi !
(Ha!! Ha!!) All appeared to be fine until my son took his younger brother for a ride last Tuesday. He said he left a stop sign and turned left on to the main road, he punch the throttle and spun the tires a little in first gear, then left off and shifted normally into second. ( This was not a full throttle flat shift) When he did the left rear wheel left the car and rolled back under the new Quarter panel and trunk extension, along with the 2 month old paint job!! Talk about sickening. 10 months and lots of $$ setting on the road with no wheel. The good news is no one was hurt !! And I'm sure you can see the bad news!!
What happened was that all 5 wheel studs sheared off flush with the axle!! I personally have never seen or heard of such a thing happening? The lugs were all tight. I know, because I tightened them. And I personally drove the car 20 miles or so and my son drove it another 20-30 miles too. I'd just like to figure out what happened, and certainly prevent anyone else from having the same disaster.
The rear was sitting for over 15 years before I installed it.

The wheels were Aluminum slots with the correct lugnuts.

The lug studs were originals, as far as I know, and came completely through the aluminum wheel

These are the same wheels and lugs the car had run for 2 years.

Could the studs have gone bad setting in a garage??

Could cold weather caused it?? It was about 20-25 out.

He said the car had some wheel hop a few days earlier, and as soon
as it started it he backed off of it. Could this have caused it. I have
had some world class wheel hop in my car and I never had anything
like this happen before.

Of course I got all new wheel studs, but I'd still like to know what
happened in the first place.

I appreciate your help!

Sick in Pa.

Ouch!!, That hurts...
The only time I sheared-off axle studs was running small bolt behind a 440 - 4-speed and 11 inch slicks. That car made hundreds of low 12 sec. passes then during one lunch, wham, no wheel.

Once had a different small bolt 8 3/4 break the flange right off the end of the axle shaft, the wheel came off with the studs and lug nuts still bolted on tight. (see pic below)

I think you just had a odd-ball failure, replace all the studs and lugs and go back at it. (you may want to check the axle shaft and wheel to be sure either is not bent and wobbling.
DD

Wheel is slightly bent, so I'll need to get another one. 14X7 aluminum slot? Anyone have one on the east coast??

Thanks,
Rick

This has happened to a few other people on mailing lists I'm on (Mopars and 4x4s alike), and I've found that a BIG cause is too litle torque on the lugnuts. This lets the rim start to shift ever so slightly on the lugs, and as the force builds up, it puts massive stress on 'em until one (then the rest) shears off. The lugs on my truck I keep at 115 ft-lbs, and for a Mopar I'd keep 'em at about 95-100 ft-lbs.

Also keep in mind, if they were new lugnuts, they have to be re-torqued after 100 miles or so due to breaking them in against the wheels.

_________________
'74 Duster w/ HEI ignition, beat to snot suspension, A904, 8.25" 3.55 SG rear, still being tuned up and gets 17 MPG

Know how they always build a better idiot? That's me

Was this a pre-71 axle and did it loose the left wheel? If so maybe someone at one time tried to remove lugs in a counter-clockwise direction and over-stressed the studs. When looking at the broken surface area, does it show all fresh metal or is there a little rusty metal with the clean?

Cecil

The rear end is out of a 70 dart if my memory serves me correct? Yes it was the left side. However the lugs were all RH. thread when I got it, years ago. All the lugs except one show clean breaks. One had what looked like fresh surface rust on the stud. I think that came from after the incident though? I didn't get to see them for 2 days after the incident.
I had replaced everything on this rear; brakes, wheel cylinders, spring kits, brake lines ...etc. The only thing I did not replace was the wheel studs. That won't happen again!!

Thanks,
Rick

The a-body 8 3/4 has 7/16" studs which makes them a little weaker than the BBP studs. But I've run them in my low 13 sec 340 4spd Dart w/slicks with no problems.
I have two possible scenarios:
You said the studs had already been changed to RH studs. The RH studs may have been poorly made and/or incorrectly installed. They are supposed to be pressed in(with the correct arbors) the flange, and then swedged. Sometimes, people pull the studs thru with there own threads. I've done it myself. But if done carelessly, I can see how the threads could easily become over-stressed.
If you don't know the complete history of this rear end, perhaps somebody ran BBP adaptors on them at one time. I've seen lotsa problems from those things.
Another complicating factor may be the aluminum wheels. Do the al. wheels pilot on the axle flange register snugly?
Do the lugnuts really bottom against the taper evenly, or did it bottom on the thread or the brake drum first?
Did you tighten the nuts gradually in the criss-cross 'star' pattern?

_________________
'66 Cuda 225/4spd
'66 Dart GT convertible 225/auto
'64 Dart GT 340/4spd

The wheels are the old aluminum slots. The wheel does not fit the center registry snugly. It is larger than the flange on the axle. However I've had at least 3 sets of these over the years, including one I purchased new and none of the wheels fit the center registry snug.
The lugs do not bottom out on the studs or go clear through the wheel and hit the axle. With the lug and washer in the wheel it still has at least an 1/8" or more before it would be through the wheel completely. The lugs were only about 2 years old and were the lugs that had been run on the car before this rear end was installed.
All the lugs were run in evenly and tightened by hand (No impact) However I did not torque them.

I just replaced all ten studs and pulled them in with the threads on the studs?? This is what I have always done. Should I now be worried about these? They were pulled in just until they were seated fully in the axle. all the wheels were then torqued to 100#.

I've never seen an aluminum aftermarket wheel that did fit the register. That's what the shank on the lug nut is for, to center the wheel. If they did fit the register, they'd have to build wheels for specific models instead of just the different bolt patterns.

I have pulled studs in with the threads and had no problems, but when I have access to a press, I prefer to do it that way.

_________________
Official Cookie and Mater Tormentor.

I think if you didn't use a spacer that fits the stud fairly closely, like a 1/2" id, and both sides flat and parallel, the stud could be pulled in crooked, putting extra stress on one side of the stud, and concentrating the stress at the root of the thread and/or at the 'relief' at the end of the thread. Lower quality threads are cut with a sharp V tool. Premium quality threads are rolled in with rolling dies. They are much stronger. That is what you get with ARP studs.

_________________
'66 Cuda 225/4spd
'66 Dart GT convertible 225/auto
'64 Dart GT 340/4spd

Does ARP make wheel studs? Or where do you get premium wheel studs?

Thanks
Rick

I am pretty sure they do. Whether they are the right size for your application, I don't know.

_________________
'66 Cuda 225/4spd
'66 Dart GT convertible 225/auto
'64 Dart GT 340/4spd

Yep, ARP does make studs for Chrysler, but they may all be long. I just bought a set of long studs for my car and cut them to fit. Mine were 1/2" diam so I'm not absolutely sure you can get 7/16", but probably.

Lou

_________________
Home of Slant6-powered fun machines since 1988

I found my axle flange "paperweight" and added a pic above.
Now that was a weird failure.
DD

Well folks, there may be a chance that the insurance Co. will pay for the damaged to the car. While we didn't have collision on it yet, we did have Comprehensive on it. My agent said that it really wasn't an accident and since no one else hit the car, that it probably will be covered by the comp. coverage. he did say it would not cover the wheel studs!! Duh!!!
I'll keep you posted.
Rick