a really dumb question

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cmac64dart

cmac64dart

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I finally have to ask the burning question I fabricated in my head this morning before I left for my day job. Why the heck do we have reverse thread lug nuts on 1 wheel on early a 7 1/4 open rear . Are all open rears like that? I'm sure there is a good reason. Please help me put this puppy to bed . thanks
 
The theory was that they might loosen up in the same direction as the wheel turns. With the left hand threads for tightening, they loosen up in the opposite direction of the wheel. Same issue with the left hand threads on the ring gear in the rear.
 
All early Chrysler cars had left hand lugs on the left side of the car, both front and rear. Not really sure what year they stopped using lefty's, but I think around 1972. After all these years, many, if not most have been changed to righty's.
PS: Mopar was not the only manufacture to do this.
 
physixx said:
The theory was that they might loosen up in the same direction as the wheel turns. With the left hand threads for tightening, they loosen up in the opposite direction of the wheel. Same issue with the left hand threads on the ring gear in the rear.
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And they found out their theory was wrong and quit doing it.:D
 
If you don't have them on the front somebody changed them.
 
Was the theory correct? do 8 3/4 open rears have the same reverse threads on one wheel?
 
toolmanmike said:
They did it for decades and they were the only ones. When nobody else's wheels fell off it was dropped.
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We had a Mopar meet locally and one of the guys that showed up in a Chevy said he had a Mopar at home but it wasn't drivable yet, but said "Here's my proof that I own a Mopar" as he handed me a left hand threaded stud.
Oh you are so in.:D
 
there is nothing wrong with the " LH theory." It just doesn't come into play because the loosening forces are small in comparison with a properly torqued RH fastener.
 
I'm a LH thread on the left side front and rear guy and proud of it!

I even made magnetic stickers to tell any wheel shops that the left side has left hand threads. LH lugs seem to be non existent for replacement.
 
I wonder how many studs were broken because the owner of the car had no idea? I guess the last resort was the impact driver and that took the nut and the stud.
 
By the way if anyone has any NOS front disk (1967 with manual Kelsey Hayes) or rear drum (1967 8 3/4, 10 x 1 3/4, or 7 1/4 10 x 1 3/4) LH lug studs they want to part with let me know.
 
A story from the old days.........Early seventies, after I got out of the Navy, a friend calls me one day, he junked out some cars. Said he had a wheel and front hub drum he could NOT get apart, "could he come out and borrow my impact?"

"Sure"

Now this guy lived about 15 miles from me, so he comes out, drops the wheel/ hub on the ground, and I said, "Mopar, uh?"

"How'd ya know"

"I can tell by lookin' at the wheel. WHICH SIDE IS IT OFF OF?"

And this funny look starts across his face, LMAO
 
I'm not going to lie I broke one before I remembered , good thing the old 7 1/4 wont be going back on the car
 
physixx said:
The theory was that they might loosen up in the same direction as the wheel turns. With the left hand threads for tightening, they loosen up in the opposite direction of the wheel. Same issue with the left hand threads on the ring gear in the rear.
Click to expand...
Yep inertia and centrifugal forces are intriguing really. I once worked on robotic assembly line machines where tiny little parts dumped from a box of 10000 into a dish like hopper would travel up a narrowing spiraling ramp until they reached their point of individual use. They "magically" lined up like little soldiers. So it was vibration that caused the travel. The spinning thumper underneath this spiral ramp had to rotate the opposite direction of the ramp. Otherwise they would never leave the dish. Go figure.
Anyway... The left hand threads on left side had much to do with the lug wrench and/or possible lack of proper torqueing the lug nuts. If they weren't tight they surely would back of.
 
Max1196 said:
Isn't there an "L" stamped into the ends of the left hand wheel studs?
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most of the time, that is true. Sometimes there is an "L" stamped on a flat or two of the lugnuts, too. If the lug nuts are open ended, you can look at the threads, and figure out if it's LH thread from the direction of the helix.
 
most big trucks run left handed lugs on left side till mid 90s and reason is thayd come lose!! the new hub pilot hubs use right hand threads and ive had them come lose couple times, there known for it!
 
dirty white boy said:
most big trucks run left handed lugs on left side till mid 90s and reason is thayd come lose!! the new hub pilot hubs use right hand threads and ive had them come lose couple times, there known for it!
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oh, it's a real thing. In physics it's called the "right hand rule." You curl the fingers of your right hand in the rotational direction of your wheel and your extended thumb points in the direction of the generated force. So for a vehicle moving forward the left side has a force pulling the wheel away from the car, and for the right side of the vehicle you have a generated force pressing the wheel towards the car.
 
There are NO dumb questions. What is dumb , is not asking when you don't know. What can happen however, is to receive some dumb answers. You are doing good so far on that.
Yote
 
The real History lesson is: When WW2 began the Military was given strict standards of vehicle assembly. All Military vehicles in 1941 forward were to have leftie, leftie, rightie rightie. There were specific reasons for it. When the War ended in 1945, GM and Ford discontinued the practice. Chrysler Corp did not. They believed in the advantages, and stuck with it. The only reason they quit in 1972 was to save money, It cost more to have two opposite patterns.
It should be mentioned that Chrysler had left handed threads before the War, and those in charge agreed it was a good idea. Also, all rear differentials regardless of size(7 1/4,8 1/4,8 3/4 etc) were equipped in the same way.



All my cars have the original studs as built, and I try to keep them that way.
 
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pretty cool stuff, I'm glad I asked . I always knew but never had it explained to me, never cared enough to ask when I was younger . Thanks again all.
 
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