My 02 ZL SS came with a .405 diameter 75* square spring (1604-818/819). I upgraded to a stiffer spring, which I believe was a .460 diameter round spring. They didn't seem to last too long. I sat on my sled today before taking the skid out, and it sank until it hit the coupler blocks. I think I remember reading on here that the square springs tend to hold up longer than the round ones. Is that correct? In my 2002 manual, my stock spring is the heaviest "square" one they show. Everything else is round.

Any reccommendations for a spring? I go about 250, and because I bottommed the skid out constantly even with the bigger springs, I'm upgrading to a ZR CC front skid shock and likely, a 190-200lb front skid shock. I'm a bit unsure what rear springs to use with this combo. The ZR CC uses a .452 diameter 90* round spring (1604-442/443 = 0704-938/939). I saw Freezerburnt suggest a 1604-388/389 (0704-944/945) which is a .452 75*. Won't the .452 90* from the ZRCC give me more preload since it will be twisted farther from its "at rest" angle?

1604-388/389s

75deg .452wire + no rubbing on the idler

great for my 260lbs carcass

I thought the CC's spring blocks may have been mounted further forward on the rails which allows more leverage because of the further distance from the point of origin. Thus a stronger spring (more preload) would be required to support an equal amount of weight. No different than adding an extension to a socket wrench handle to loosen a rusted bolt. Not sure if there is any truth to this but it's something to think about.

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I was going to post if the rear springs weaken like the front ones do becuase it doesn't hold up the back of my sled like it used to so now i'm thinking about replaceing the rear springs.

Go with freezerburnt,I weigh 270 before the suit and those work.

I knew that would be confusing lol

What I noticed was on the standard ZR the long part of the spring is shorter than on some of the upgraded models.

If you have a longer spring it would be the same has adding a pipe onto you socket wrench to loosen a rusted bolt. You are using less force at the end of the handle to produce the same amount of effort to removed the rusted bolt.

On a CC model with the longer spring (mounted further forward) You've just reduced the amount of lift that sled can support, hence the reason for adding an extra 15 degrees of turn on the coil end of the spring, to compensate for the leverage factor.

I made a picture too.

Click to view attachment

Kev, on all the ZR's that I have taken apart with the TSL rear skid the spring support has been the same location, basically the same axle bolt that holds the front of the rear shock.

The 75* spring should give you slightly more pre-load as I understand it. I don't think you will find the springs freezerburnt suggested too stiff. I use the equivelant (0704-944) and I am only 200 lbs. The extra preload should stop the sagging that some experienced with the 90* springs that came on some of the stock ZR's.

Good luck!

The springs that freezerburnt and myself have on our sleds should work good for 250lbs,I have mine cranked up to the high preload and they work great,that should give you enough adjustment.

You don't have your sled sitting on dollies, do you?

I was just looking at Browns, comparing the 2002 ZR to the 2002 ZR CC. The CC spring block is mounted closer to the rear of the skid which is the opposite of what I had previously thought. There goes my theory.

yes, I do, but the suspension is at its maximum height when it's sitting there. Next year I should build a couple stands for them though.

Good catch, you are right, all the ones I have had over the years were always on the same axle bolt as the rear front shock mount.