Should I upgrade Leaf Springs?

[Jblackwell205]

Hey guys, I have a 1997 GMC Sierra K1500. I’ve had the truck since new. Has 376k miles and still runs like a top. Question I have is I’m about install some new Bilstein 4600s (well overdue) will be my third set of shocks on this truck. My question is though. The rear leaf springs is OEM. Truck doesn’t appear to sag but at the same token I have no idea what the factory height was. I’ve inspected the leafs (not loose, no cracks). Alabama truck so nearly zero rust. My rear fender measurements are Driver Rear-34.5” and passenger rear is 35.25”. I plan to keep this truck awhile. Not a daily driver but would it be worth going and ahead and installing new 3+1 rear leaf springs? It has towed a lot and been loaded heavy over its life but not a daily anymore and only tows lighter weight occasionally nowadays.

 

[Lou32]

I had replaced the rear springs on my 1990 k1500 and wasn’t a bad move. Fairly inexpensive too. I’ve since added an add a leaf. Airbags might not be a bad idea, adjustable for height and or added carrying capacity. But personally I was pretty happy with the new springs. Got them on rock auto. If I remember right about $170 for the pair

 

[GoToGuy]

Replacing because you feel like it is okay. But is there really a problem? Do have a cracked leaf. Are the plastic friction sliders missing. Do the bushings in the leaf eyes need replacing? There is no time life service limit on leaf spring. Inspect regularly and replace repair.

 

[RichLo]

^ yep

And to add, I would trust OEM springs more than anything aftermarket.

The Plow truck in my avatar had and OEM spring pack with a bunch of aftermarket Add-A-Leafs in them when I busted the rear axle. When I dropped that axle out, almost all of the aftermarket leafs crumbled and the OEM ones were still just fine. I then replaced the aftermarket crap with cut-down OEM leafs from different vehicles I had on-hand.

It now has 11 leafs per side and still only an inch away from the bump stops because of all the weight in the bed.

 

[Schurkey]

1997 GMC Sierra K1500.

Truck doesn’t appear to sag but at the same token I have no idea what the factory height was.

Ride height is going to be listed in the service manual set. Download the service manual set for your vehicle from the links in the Sticky threads section of the Engine forum.

 

[someotherguy]

If it ain't sagging considerably (all these trucks "lean" a tiny bit) and you don't see any obvious defects like cracked leafs or blown out bushings, and you're happy with the existing ride quality and load carrying capability, don't mess with it.

Richard

 

[skylark]

If it ain't sagging considerably (all these trucks "lean" a tiny bit) and you don't see any obvious defects like cracked leafs or blown out bushings, and you're happy with the existing ride quality and load carrying capability, don't mess with it.

Richard

It's like a sore d!cl<, don't fucl< with it!

 

[JJF20]

OP. Springs, like anything else, wear out. They are a consumable. If they are the original springs they will have lost a lot of their weight carrying capacity, and not evenly either, one side usually sags more than the other.

These trucks do not (should not) lean, or need air bags to handle the weight - assuming you are not grossly over loading it and have the correct springs etc. Air bags won’t fix worn out springs.

There are several aftermarket options. ATS, General springs, etc. I’d recommend new shackles, hardware, ubolts (ubolts are a one time use only item) while you are at it. Make sure they come with new bushings already installed (any reputable supplier will already have that, it’s good to ensure though).

A lift is really nice for this job, and if you’re not up for it a shop can swap them out relatively quickly.

 

[Lou32]

Hey guys, I have a 1997 GMC Sierra K1500. I’ve had the truck since new. Has 376k miles and still runs like a top. Question I have is I’m about install some new Bilstein 4600s (well overdue) will be my third set of shocks on this truck. My question is though. The rear leaf springs is OEM. Truck doesn’t appear to sag but at the same token I have no idea what the factory height was. I’ve inspected the leafs (not loose, no cracks). Alabama truck so nearly zero rust. My rear fender measurements are Driver Rear-34.5” and passenger rear is 35.25”. I plan to keep this truck awhile. Not a daily driver but would it be worth going and ahead and installing new 3+1 rear leaf springs? It has towed a lot and been loaded heavy over its life but not a daily anymore and only tows lighter weight occasionally nowadays.

I agree with others posting here on their very valid points. Yeah I replaced my springs, but were VERY rusted, bushings dried out and cracked, pads shot,etc. and I certainly agree about OEM being good stuff. But in my case mine were worn out and aftermarket worked for my situation. But certainly if I had OEM springs in good condition I wouldn’t replace them.