Why pre-load spacers???

[B-Mitch]

Why are pre-load spacers selected over spacers that sit on the top? Why would you want to compress your springs to attain the lift, messing with the spring progression and rate? Wouldn't it be a better ride to use the spacers that don't compress the spring?

I'm sure there's a reason, because most of the leveling lifts I see use the preload spacers... I just don't understand.

Thanks for any info

 

[dts828]

Copied from another site:

Pre load spacers will stiffen your suspension a bit and limits the ability of the strut to fully compress. In severe cases it can cause coil bind.

Top spacers just lowers your strut by that amount. The issues is still that the strut now operates that much lower, so your bumpstops will not protect it as much as in the stock suspension. But it wont affect the "stiffness" of the ride. The advantage of the top spacer is that it allows your strut to droop lower than stock, thereby increasing flex slightly. However if you add too much, you can bind the A-Arm ball joints or they can hit the coil itself.

Sent from my GM1917 using Tapatalk

 

[B-Mitch]

Thanks dts!

 

[MJH19RAM]

Yes, the benefit is exactly as stated above. If you use a spacer that fits on top of the strut assembly (top-hat), the entire assembly is then longer and can therefore possibly overextend the designed angle of the upper control arm ball joint at full droop, according to the popular belief. This is the reason most top-hat style kits come with new control arms. The benefit of this style of lift is that the spring doesn’t have any added pre-load, so it won’t ride much stiffer.

With pre-load spacers, the overall length of the strut assembly is unchanged, but the increase in spring pre-load causes the truck not to have as much static sag. It just rides higher in the original “range of suspension. The benefit is that you theoretically can’t overextend the ball joint angles any further than stock at max droop. The angles are just a little steeper at normal ride height, which isn’t a big deal. The downside is that if you don’t get shocks that are valved for the pre-load, it will give the feel of a stiffer ride.

Some kits out there use both for added lift height, like the 3.5” kits from R/L or R/C. I had a 2004 F-150 FX4 once that I combined pre-load and top-hat spacers on to get 3-3.5” of lift on. It looked great but the ride was very stiff...

 

[B-Mitch]

Awesome info MJH... Thank you!