M1028 replacement rear leaf springs ???

[Drock]

I thought I'd better start a new thread on this portion of my lift saga. After finally finishing a 2-1/2" lift on my M1028 using a skyjacker kit in the front, and ORD shackle flip & U-bolt flip in the rear. I noticed I have a broken rear leaf. After several phone calls to online sources I've come up with 2 possible candidates for a stock replacement for the M1028 but I'd like a CUCV experts opinion on this before I order. Here's the 2 part numbers I came up with (22-617, 9+1 leaves, 3955LBS spring) & (22-617HD, 9+1 leaves, 4650LBS spring) Both are 56" springs. Are either of these the correct LBS spring as my stockers?

 

[truck1]

Try Boyce Equipment for a rear 1028 spring replacement. I went through the exact same scenario as you with a cracked leaf. Boyce set me up with a take off near NOS replacement. I think it was 100$ plus shipping. Tell them it's for a CUCV 1028 and they'll send you the right spring ready to install.

 

[Drock]

Well score!! I stopped at a local repair shop today and the owner happened to have a set on an axle he just pulled yesterday. I also scored a right side fuel tank. $80.00 for the springs, $75.00 for the tank with brackets.

 

[MarcusOReallyus]

Nice score, Drock!

How are you going to set up that extra tank? Switch in the cab?

 

[Drock]

Nice score, Drock!

How are you going to set up that extra tank? Switch in the cab?

Yeah that's the plan. I've just got to find/order the valve thing and switch. I've really needed to add a second tank for a while. I put 3000+ miles per month over the road on this truck and it will be nice to have the extra capacity.

 

[cucvrus]

Drock I don't want to be a negative person. But I have been down this road many times. The used springs have held the weight of the truck they came off off for 30+ years. They are not the best deal to put on a truck. When you figure the time and energy to put them on. They are not all that expensive to purchase new. I do not know your financial situation and will not ask. But I would think that the $450. spent on the new rear springs in the long run would be the way to go. I have been changing a lot of springs out in the last 2 years due to the springs reaching that age of total fatigue and the new springs have made a world of difference in the driving and ride of every CUCV I put them on. Of course do as you want. I am trying to help out. I like to use anything I can used but at this late time in the age of the springs. I do not use used springs or transmissions any more. They have surpassed the shelf life and are going to be needing attention sooner then not. Good Luck.

 

[Drock]

Drock I don't want to be a negative person. But I have been down this road many times. The used springs have held the weight of the truck they came off off for 30+ years. They are not the best deal to put on a truck. When you figure the time and energy to put them on. They are not all that expensive to purchase new. I do not know your financial situation and will not ask. But I would think that the $450. spent on the new rear springs in the long run would be the way to go. I have been changing a lot of springs out in the last 2 years due to the springs reaching that age of total fatigue and the new springs have made a world of difference in the driving and ride of every CUCV I put them on. Of course do as you want. I am trying to help out. I like to use anything I can used but at this late time in the age of the springs. I do not use used springs or transmissions any more. They have surpassed the shelf life and are going to be needing attention sooner then not. Good Luck.

Duly noted, but I'm confident this set is in much better shape then my originals (once I wash the red Georgia clay off them), plus now I have a spare.

 

[afc2324]

I thought I'd better start a new thread on this portion of my lift saga. After finally finishing a 2-1/2" lift on my M1028 using a skyjacker kit in the front, and ORD shackle flip & U-bolt flip in the rear. I noticed I have a broken rear leaf. After several phone calls to online sources I've come up with 2 possible candidates for a stock replacement for the M1028 but I'd like a CUCV experts opinion on this before I order. Here's the 2 part numbers I came up with (22-617, 9+1 leaves, 3955LBS spring) & (22-617HD, 9+1 leaves, 4650LBS spring) Both are 56" springs. Are either of these the correct LBS spring as my stockers?

"Here's the 2 part numbers I came up with (22-617, 9+1 leaves, 3955LBS spring) & (22-617HD, 9+1 leaves, 4650LBS spring) Both are 56" springs. Are either of these the correct LBS spring as my stockers?"

Im going through the same thing now but I havent been able to find the answer to this question. Which rear springs are correct as an oem replacement? The 3955 or 4650?

 

[RattleSnack]

"Here's the 2 part numbers I came up with (22-617, 9+1 leaves, 3955LBS spring) & (22-617HD, 9+1 leaves, 4650LBS spring) Both are 56" springs. Are either of these the correct LBS spring as my stockers?"

Im going through the same thing now but I havent been able to find the answer to this question. Which rear springs are correct as an oem replacement? The 3955 or 4650?

This one got me curious since I have an M1028 also.

I found this on RockAuto's website. The 3955lb springs have a 4-1/16" pack thickness...


...and the 4650lb springs have a 4-5/8" pack thickness.


After discovering this info, I ventured down to the garage (since my M1028 is in hibernation from the winter salt ) and measured my spring pack...


As you can see, mine has 9 leafs plus 1 overload. It measured right at 4-5/8".....so, it looks as if the 4650lb springs are the correct ones that originally came on the M1028's. Mine has 56k miles and is all original except for the 4" lift and 35" tires. So, I'm 99% sure these are the original springs. Don't mind the crud on the springs....that's just the Fluid Film I like to use.

Anyways, hopefully this helps you out.

 

[afc2324]

This one got me curious since I have an M1028 also.

I found this on RockAuto's website. The 3955lb springs have a 4-1/16" pack thickness...
View attachment 941443

...and the 4650lb springs have a 4-5/8" pack thickness.
View attachment 941444

After discovering this info, I ventured down to the garage (since my M1028 is in hibernation from the winter salt ) and measured my spring pack...
View attachment 941445

As you can see, mine has 9 leafs plus 1 overload. It measured right at 4-5/8".....so, it looks as if the 4650lb springs are the correct ones that originally came on the M1028's. Mine has 56k miles and is all original except for the 4" lift and 35" tires. So, I'm 99% sure these are the original springs. Don't mind the crud on the springs....that's just the Fluid Film I like to use.

Anyways, hopefully this helps you out.

Thank you for this! I guess whats throwing me off are the pics on Rockautos page dont show an overload spring and they have no customer service line where you can ask questions.
Is your front spring pack a three spring or a four spring?

 

[RattleSnack]

No problem!

Yeah, the pictures you see on RockAuto, Amazon, etc....are not always a pic of the actual part...(I hate when they do that!!) The 22-617HD's are a 9-leaf + 1 overload. If you look at my pic, you can see that there is a band right next to the tape measure that goes around the entire spring pack and overload....so it should come as one unit.

My front springs are Skyjacker CS-140's since I have a 4" lift on my M1028...so we can't go by that.


However, I also have an M1031 that is completely original. It has the 3-leaf pack in the front...

The part number for the 2-leaf front spring is 22-400. The 3-leaf spring part number is 22-402. Now they do make a 4-leaf front spring, which is part number 22-402HD, but I don't think a 4-leaf spring ever came factory from GM. The 4-leaf spring was probably something the aftermarket created for folks who needed a heavier spring for snow plows, winches, Cummins swaps...things like that.

So if you're looking for a completely stock set-up, you would want the 22-402's in the front and 22-617HD's in the back.