patented

[jimwrench]

 Patented by whom for what ?
right and left hand thread.
washer like piece in end of nut has 5/16 thread that is only about three threads deep.
PM and patd are only markings.

[EVILDR235]

That is a spring shackle for a old car or truck back then you greased them. They were replaced by rubber mounted spring shackles.



EvilDr235

[rusty]

Why would it need left hand threads?

[jimwrench]

 Don't know.  its not like any spring shackle I've seen. If you put grease in the end it would grease the threads but not the leafs. I'm guessing automotive but not convinced on automotive what.

[EVILDR235]

Go to a search engine and type in Dodge spring shakles 1940s and you will see several pictures of them. I was in the auto wrecking trade for over 35 years and removed and replaced many of them.

Evildr235

[wrenchguy]

its not flat where it would come in contact with the spring........  fits into a saddle then the spring????????

[jimwrench]

 I went I saw I am convinced. Now what do I do with one of them. take it to auction and see if anyone is working on 1940's Dodge.

[EVILDR235]

That is  a shakle,not a u-bolt. One side goes in the bracket on the frame and the other in eye hole of the spring. Several different car makers used this system. Not the best setup.

XXXXXX

[Chillylulu]

Shackle on top, u-bolt on rear driveshaft. See the beautiful old Buick below:





I hope this helps to clear up the difference. 


Chilly

[eddie hudson]

Why would it need left hand threads?

It has something to do with keeping the whole thing tight. One side of the car had right handed thread on both upper and lower while the other had left and right.

[Billman49]

Never seen an open ended version in the UK - they are usually found with a plate either side of the spring and hanger....



as per this repair kit for a 4x4, and this from the same web page...