History Chrysler's LH Thread Wheel Studs

Anyone on here know the history and why they used LH threaded Wheel Studs on the LH side of he vehicle. Has anyone changed these to RH thread without problems? Thanks, I just need a history lesson.

 

They are easily changed. They were LH so they wouldn't loosen up driving forward.

 

I thought that was the case, but no other mfg had this, so I will change to RH thread for convenience

 

several other makes used them...studebaker for instance also common on trucks

 

1951 pontiac also has lefties on left!

 

IIRC, Studebaker had this also, and Hudson also, I think. I do know you could take the hubs off, knock out the studs and any parts store that was worth a shit had a Dorman cabinet with new lug bolts and nuts in RH thd. of the correct dimension to change it over.
Dave

 

I wanna know why the 56 plymouth has studs and nuts up front, and bolts in back. Each wheel has different hardware holding it on

 

61 Tempest as well,,and the car had a Sm Ford bolt pattern to boot ,,lol

 

My '57 Plymouth has just bolts holding the wheels.
Not for long though...

 

Most manufacturers except Ford used the L/R threads at some time. The engineering principles are sound, it's just a pain to deal with in the real world.

Squirrel, I've never heard that before! I've never heard of a Mopar that had mismatched lugs/bolts from the factory. I know my '57 Plymouth had bolts originally and that there are some cases of Plymouths using these through 1959. My '57 Chrysler has lug nuts and I believe Chrysler stopped using lug bolts completely after 1956.

They were doing some weird chit, that's for sure...

 

Not sure on that one, sickgirl's 55' Dodge Coronet has studs and nuts all around. Axle/rear end swap maybe?

 

I've had several Mopars with both studs and bolts.
Just about every tandem and semi with Budd wheels has left hand thread on the left side. Have you ever lost a wheel? It's almost always the left rear one that comes off. Never seen an old Mopar lose a wheel, lots of Fords and Chevy's,though.

 

Willys and Kaiser Jeeps had LH threads...my '50 Chrysler has bolts holding the wheels on

 

I had two 56 plymouths, they both had bolts in back and nuts up front. Ever try to find a left hand wheel bolt?

 

I have a 1937 Plymouth pick up and bolts front and rear .
I had a 67 Chrysler T&C wagon with disc brakes and both L&R thread .
Had a 69 Dodge Super Bee with the same L&R hand threads .
None of the lugs ever came loose either !

RetroJim

 

I believe that the LH threads had to do with the machinery used in the assembly plants.
For those folks who are familiar with old industrial plants using 'lineshafts', you will understand the principle of equipment being turned, mechanically, in one direction. No impact guns in 1909...

I do not believe there is an engineering principle related to lug nuts, as we know them, loosening while driving or the problem would still be with us and likely be amplified by the speeds that we drive compared to the 'old' days.


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i remember snapping off 3 lugs on my 36' plymouth before i was shown the correct way to remove a wheel.

 

Got them on my Chrysler, couldn't really see a reason for it.

Always made me laugh that some same year GM cars had it and some didn't,
If you bought a Chevrolet, then all your wheels can fly of and you'll die, but if you paid for a Buick we'll look after you with these speacial left hand threads..

 

Never heard the one about the machinery at the plant being the reason. Good story, it just ain't true! I think the factories would have updated by now at places like Navistar, Kenworth, and like that, by now!
I've seen and had to fix cars and trucks that lost the left rear wheel, too many times to count. '47 Ford, '59 Ford, '63 Merc, Ford pickups, were all our vehicles, and a few neighbours brought theirs over to get fixed. '70 Chev 3-ton, '62 Pontiac, many more. All left side, all but the Pontiac were rear wheels. Coincidence? I think not!

 

Perhaps (just thinking out loud here) because wheel technology wasn't upto snuff yet and wheels at the time were too 'flexible' for the engineers to think the lugnuts would work themselves loose during use?

 

Gotgas is correct.It's a sound engineering principle in order to reduce the risk of the L/H wheelnuts coming loose in forward motion.Probably over-engineering as far as cars are concerned.Used by many high end manufacturers including Rolls Royce.
Don't know about now but,used to be used on many heavy and specialist vehicles.

 

My 56 Cadillac hearse has lh studs as well. Don't know if it was all caddys of that time or just commercial chassis ones.

 

I suggest the left-hand, left side "phenomenon" is due to early cars having spindle-mount wheels/rims with a single spindle nut, and the tradition carried over to the multi-lug hubs/wheels. Even today, when running true knock-offs, the left-hand thread goes on the driver's side. (Just ask anybody with a blinged-out ride and 20" rims.)
The reason we hear so much about it with Chrysler products is that they carried it on up to '70 or '71.

Roger

 

I don't see what difference it makes as long as ya know it. I wouldn't go though the work to change it, just me I guess.

 

I agree with you. If the proper tension is achieved in the stud thru the torque applied the nut should not loosen.

 

The engineering term for the "need" to have LH wheel studs is called precession. It is also the reason that bicycle pedals are threaded L and R.

I've driven lots of cars with all kinds of lug nuts, and never lost a wheel. Just lucky, I guess.

 

Buick, Studebaker just to name a couple that I know for a fact used lefties and righties. With the Buicks its a little harder because that used studs and threaded flanges instead of lugs and nutz.

 

if anyone needs the bolts i got mine from roberts motor parts they have rh and lh, mopars ,backwards threds, upside down keys,gotta love um.

 

How would you change these over to rh thread?

 

does anyone no where to get left hand thread studs and nuts?