The 67-72 drivers front spring hanger strap and shackle stop thread

[57taskforce]

There has been some discussion on another thread here, I’d like to document and learn more about when the strap and stop became Oe equipment on the frame vs. a recall addition. I believe they became standard equipment in 72. The reason I say this is because the recall front hanger strap is different than the straps I’ve seen on a few 72’s. Also a part number was posted for the strap and stops. I did some research and it lists as 70-71. I’ll post some pictures up from that thread, credit to too much stuff for his picture contributions which I will re post here.

First I will post pictures of my trucks, a 69 K10 short bed, and a 72 K20. Note the spot welded strap on the 72 which does not have the lower mounting areas that the other trucks pictured have, and no strap on the K10.

I will add the rest of the pictures in a little bit.

[57taskforce]

Now here are some pictures that Too Much Stuff shared of his trucks. Note that they all have the same style of “cage” type front strap that seems to be welded to the hanger via a bead rather than the spot welds on my ‘72. Also note the part number on the box, as said above I searched that number and found several NOS examples all listed for 70-71.

[57taskforce]

And finally here’s a few too much stuff posted of the strap kit which I presume is for the recall. I found a few for sale online. I think I might add one to my K10.

Note the difference in shape and design of the front strap compared to the one on my truck. To me these have to be related to the recall because I doubt GM would sell this weld on part of a frame. As I said, I looked up the pry number and it lists for 70-71. This also confirms in my mind that only 72’s came with the spot welded strap from factory (why would GM sell a bracket kit for a frame that should have already had them from the factory?) I suppose that it is possible that maybe there could have been plant variances but I’m skeptical.

All this long winded stuff aside, post up some pictures of your spring straps and let’s see what’s out there, I would love to see some pre ‘72 trucks that maybe have the spot welded strap.

[GSP7]

What be the purpose of that strap/ stop ?

What happened that required it?

something to do with the steering forces ?

Trucks hitting Huge attack boulders on the drive side spring perch?

[57taskforce]

They were there in case the spring eye bolts were to break. They helped keep the spring in place to maintain steering ability until the truck could get stopped(I’m sure sometimes much longer) also I’ve seen some say that the rear bracket helps to keep the spring from coming thru the floor in the event of a bad crash.

[BLAZERMAN]

Originally Posted by GSP7

What be the purpose of that strap/ stop ?

What happened that required it?

something to do with the steering forces ?

Trucks hitting Huge attack boulders on the drive side spring perch?

The strap and spring stop were part of a recall starting in 1969 due to main leaf springs breaking at the spring eye. It was only necessary on the driver's side due to the draglink being on that side....if a spring were to break the sudden drop would automatically veer you off the road or into oncoming traffic I bought a 1970 K-20 once at an auction and drove it 100 miles home. I even drove it to work and back for a week before finding out my driver's side main leaf was broke right at the eye. The spring was captured at the front by the strap and couldn't come back far enough to come out due to the spring stop. It had done it's job and the truck didn't handle odd or even sag on that side. Starting in 73 they went back to the "military wrap" spring in which the secondary leaf also makes a full wrap at the front leaf eye.

[Dieselwrencher]

Originally Posted by BLAZERMAN

The strap and spring stop were part of a recall starting in 1969 due to main leaf springs breaking at the spring eye. It was only necessary on the driver's side due to the draglink being on that side....if a spring were to break the sudden drop would automatically veer you off the road or into oncoming traffic I bought a 1970 K-20 once at an auction and drove it 100 miles home. I even drove it to work and back for a week before finding out my driver's side main leaf was broke right at the eye. The spring was captured at the front by the strap and couldn't come back far enough to come out due to the spring stop. It had done it's job and the truck didn't handle odd or even sag on that side. Starting in 73 they went back to the "military wrap" spring in which the secondary leaf also makes a full wrap at the front leaf eye.

Rob hit it right on the head for the reasoning. 72 was the only year that had them. All the rest were added in the recall and it's pretty rare to see them. I've had and found quite a few 67-71 K trucks and only ever seen 1 added strap recall truck. I knew a guy that had a 71 that had the gm parts for his grandfather's truck that were never put on it. If you put a new style lift spring on the truck you get the military wrap type spring and don't need this strap but it is definitely something cool about these trucks history.

Here is a bad pic of a 72 K20 I got last year. It has the strap on the LH front hanger. I'll get better pics later. The 2nd pic is one on my Longhorn from years back.

[CUSTOM/10]

Years ago I had this happen to me on a hunting trip in Northern Maine. It was a 72 so it had the strap and stop on it. On a really rough dirt road I heard a bang, got out and looked around but saw nothing. It wasn't until I got home (400 mi) that I found the mane leaf had broken at the eye bolt. So this thing really does work.

Gary

[57taskforce]

Awesome input guys! I knew the stock springs just had the single wrap but it never occurred to me that was the point of failure. Makes complete sense. I love documenting true history on these trucks.

[Dieselwrencher]

I decided to check my other K20 to see if it had these. I always thought it was a 71. It has 68-71 doors on it and the PO said it was a 71 so I just went with it. Yesterday I was looking to see if it had the safety strap and stop and it did. I was kind of excited because being it was a 71, it would be one of few that came with it. But no, the VIN clearly shows it is a 72.

[pjmoreland]

Do you happen to have a higher quality photo of the shackle stop installation instructions where the installation gap dimension is legible?

[pjmoreland]

I found a slightly better image. Looks like it's 1/8"

[Richard]

Wanted to note the 1/8" gap would be for stock type flat/ slightly negative arch springs. The springs get shorter as suspension cycles. When running positive arch lift springs that gap would need to be larger (or stop removed) as springs get longer when compressed. Damage may result with spring constantly hitting stop. Then again, most aftermarket lift springs do not move much

[pjmoreland]

Originally Posted by Richard

Wanted to note the 1/8" gap would be for stock type flat/ slightly negative arch springs. The springs get shorter as suspension cycles. When running positive arch lift springs that gap would need to be larger (or stop removed) as springs get longer when compressed. Damage may result with spring constantly hitting stop. Then again, most aftermarket lift springs do not move much

Thank you. My truck has stock springs, I believe, as they are very close to flat with no drivetrain installed. I will need to recheck the adjustment after I install the drivetrain. The frame and stop were beat up from prior improper adjustment.