Proper Way to Measure a Leaf Spring

**Crawdaddy** · 09-16-2009, 03:03 PM

Hey all!

I am in need of new springs for my Suburban. However, they list 2 possible springs for my application. One spring is listed as 52" long and the other is listed as 56" long. Measuring the spring from eye to eye while on the truck I think yielded me right around 52", but measuring along the curve of the leaf pack yeilded me around 56". I did a little googling and found this link: http://www.eatonsprings.com/measuring.htm and it only served to confuse me more. I think my measurement along the curve of the leaf pack, in other words, bending a measuring tape so it's touching the leaf the entire way, is the right way to measure, but I'd like some reassurment before I go ordering springs that don't fit for one reason or another.

Thanks!

**bigburb** · 09-16-2009, 04:23 PM

Well, I just measured my rear springs, and from bolt to bolt it's 56". I'm inclined to believe that they are 56" because my stock rear springs aren't too far from flat

I measured my front springs, which were about 46" bolt to bolt. Of course, they have a lot more of an arch to them than the rear. I do think they're shorter than the original front springs, tho. I don't know if GM used different springs on the rear of the old 'burbs depending on whether it was 2 or 4wd, but it would make lif easier if they dind't lol. I was just trying to see if maybe the 52" springs were for the front, but I don't have my factory fronts anymore.

It's kinda strange that we got different measurements, but maybe they are different lengths

**tbplus10** · 09-16-2009, 08:09 PM

Different manufacturers will have different measuring methods, but most measure eye to eye. Before you buy your springs contact the manufacturer and make sure how they measure theirs.
Chevy uses a 52" eye to eye and a 56" eye to eye spring. I know 1988 to mid 90's 2x4 1/2 ton trucks use a 52" but I'm not sure if the measurement is the same for Suburbans of that era.

**bigburb** · 09-16-2009, 08:14 PM

If I remember correctly, the suburbans used longer rear leaf springs. I could be wrong though... If our "local" junkyard was a little closer I'd go out there and measure for ya. There's always a few completely unneeded things I could pick up there lol.

**Crawdaddy** · 09-16-2009, 08:34 PM

Mind you, I have not measured my spring packs recently, but I distinctly remember coming up with both possible spring lengths when I measured different ways. Guess I need to get out there and measure again. Also, my rear springs are darn near flat like yours bigburb. The one trick that COULD redeem my oddball measurements is that the website I mentioned says that the springs have to be off the vehicle to be accurate. I'll try to get out there and measure them again tommorow.