Question about front eye bolt and nut for leaf springs

[aaron72]

I just received my new leaf springs from ESPO, and I also purchased their hardware kit which comes with the shackles and bushings, U bolts and the front eye bolts and nuts.

As I was going through the hardware kit, I always test out the bolts and nuts to make sure they work correctly and I came up on something withe the front eye bolts that I'm not sure if it is normal or if there is a problem.

As I was threading the eye bolt into the nut, the nut stops about 2 to 3 threads short of the end of the bolt being flush with the opposite side of the nut.

When looking at the opening of the nut, to my naked eye it seems to be a bit out of round and at certain parts of the threads they appear to be a bit squared off instead of rounded.

My question is, is this a special type of nut designed this way to resist vibration and loosening, or are these defective nuts?

I've tried to take pictures of what I'm seeing to be able to provide the best vision, but it's easier to see in person, but let me know what you think.

Looking in the parts catalog, I see it just shows a bolt and nut, no locking washer of any sort.

When doing a google search for the Mopar part number for the nut, I get a few hits and they show Marsden nuts with are designed as self locking.

I crawled underneath the car in the driveway, but it was hard for me to see as the car is undercoated and the nut is in between the front mount and the frame. I felt the nut, but I didn;t seem to feel any notches like the Marsden nut would have, but I'm not sure if I'd be able to feel them if they are supposed to be very narrow.

Just looking for some assistance to know if:
1. these nuts are correct and will be hard to fasten and that's the way they should be to reduce the likely hood of them loosening during use
2. these nuts are defective and I need to go get better nuts
a. do I need to get a specific type of nut for this front eye bolt

Any insight would be greatly appreciated. I'm reaching out to ESPO as well and will report back any findings.

 

[Big_John]

That's a lock nut and used so the nut doesn't loosen. In a perfect world, it would only be used once.

 

[CBODY67]

Yes, a "prevailing torque" "lock nut". Made by deforming a normal nut in 2-3 places around its circumference. Used by OEMs in many places, since the 1980s and such. Where I encountered it was in the OEM replacement nuts on exhaust manifold-to-exhaust pipe studs on Chevy engines at work.

This type of nut obviously is more reliable than a separate lock washer that can be lost or not installed by the end user. DO put a flat washer between the nut and the spring part it is associated with.

Enjoy!
CBODY67

 

[aaron72]

Thank you, guys. It was a bit of hardware I was unfamiliar with.

Laura from ESPO confirmed that it is a Stover lock nut that uses distortion of the top threads to create the friction to reduce loosening exactly as CBODY67 described.

 

[mgm1986]

Thanks for sharing! I have new springs and hardware from ESPO waiting to be installed at the end of the season.

 

[RemCharger]

If your originals are in good shape like they often are.. I'd re use them.

 

[Gerald Morris]

I just received my new leaf springs from ESPO, and I also purchased their hardware kit which comes with the shackles and bushings, U bolts and the front eye bolts and nuts.

As I was going through the hardware kit, I always test out the bolts and nuts to make sure they work correctly and I came up on something withe the front eye bolts that I'm not sure if it is normal or if there is a problem.

As I was threading the eye bolt into the nut, the nut stops about 2 to 3 threads short of the end of the bolt being flush with the opposite side of the nut.

When looking at the opening of the nut, to my naked eye it seems to be a bit out of round and at certain parts of the threads they appear to be a bit squared off instead of rounded.

My question is, is this a special type of nut designed this way to resist vibration and loosening, or are these defective nuts?

I've tried to take pictures of what I'm seeing to be able to provide the best vision, but it's easier to see in person, but let me know what you think.

Looking in the parts catalog, I see it just shows a bolt and nut, no locking washer of any sort.

When doing a google search for the Mopar part number for the nut, I get a few hits and they show Marsden nuts with are designed as self locking.

I crawled underneath the car in the driveway, but it was hard for me to see as the car is undercoated and the nut is in between the front mount and the frame. I felt the nut, but I didn;t seem to feel any notches like the Marsden nut would have, but I'm not sure if I'd be able to feel them if they are supposed to be very narrow.

Just looking for some assistance to know if:
1. these nuts are correct and will be hard to fasten and that's the way they should be to reduce the likely hood of them loosening during use
2. these nuts are defective and I need to go get better nuts
a. do I need to get a specific type of nut for this front eye bolt

Any insight would be greatly appreciated. I'm reaching out to ESPO as well and will report back any findings.

It's EXACTLY RIGHT for the job they meant it for. You're far better off using this sort of nut than to have some Yahoo armed with a stick welder that would ruin the bolt and nut by dabbing some slag onto both to hold it in place. Thank ESPO for their consideration. I replaced the pair they sent me with my kit when I moved their springs from our '66 to our '68.