New 5100s

This is not correct nor how 5100s work. There is a video somewhere from Bilstein showing how they work and they don't preload. I'm at the top notch and spring length is the same as stock. This is with stock springs. Using different springs could be different.

 

Stock springs? I'm on the top notch and the ride is very similar to stock but a bit better manners. Less nose dive and corners a bit better.

 

That is what Bilstein so I tent to think there on point. That's what I have been saying!

 

Preload is how compressed the spring is on the coilover before the weight of thee vehicle compresses it. Whether you move the lower perch up to compress the spring before installation on the vehicle or put a spacer between the top of the spring and the "hat" of the coilover you have increased preload.

 

Ride is extremely subjective but I drive tons of Tacomas at work and have done quite a few 5100s. Max is awful and I tend to touch the roof with my head on trucks with maxed clips.

 

Nothing is compressing the spring but vehicle weight.

Since the weight of the vehicle does not change, the amount the spring is compressed at rest does not change as a result of where the bottom of the spring starts.

 

Not specifically about the 5100s, but this shows how preload changes the height but does not compress the spring.

https://accutuneoffroad.com/articles/coilover-spring-rates-for-toyota-tacoma-4runner/

"Some people associate preload (loosely related to threads showing above spring nut) with a harsh ride because they are “cranking down” the spring. Increasing preload only raises ride height, it does not compress the spring more, and it does not make the ride rougher. The only time too much preload causes a rough ride is if you lift it too high and don’t have any down travel, or if the spring runs out of travel before the suspension bottoms out."​

 

Take the coilover out of the truck, put it on the workbench, and take the center nut off of the hat. After the spring flies off and hopefully doesn't injure you, you'll realize that the spring was absolutely compressed before the weight of the vehicle was put on it.

 

If the top hat is in a fixed location and you move the lower perch closer to it you have compressed the spring more because there is less space between the two.

 

Try a little thought experiment. Imagine the truck with 5100s on the lowest setting. The truck sits at a given height and the weight is resting on the spring to give it that height. Now imagine moving the bottom perch to the top one. If doing this only compressed the spring, the ride height wouldn't change. In reality, moving the perch up moves the whole truck up and the spring retains the same compression as before.

Look closely at the Accutune explanation. The spring at ride height isn't changing length. Instead, the the top mount attached to the frame moves up and thus lifts the truck.

 

I have taken them apart, a few times. The preload does not change by clip setting.

Because physics.

 

Now I understand what you were saying. I

Are we not talking about the same thing? If the shock is on the bench and you move the perch up a notch you're saying you have not increased preload?

 

Here’s my alignment numbers

 

Thoughts on upgrading the coils to OME? For better ride quality?

 

Hell yes, especially if you are carrying weight

 

How can you say this when you need to use a spring compressor to assemble the coilover in the first place?

 

I don't think it will get you better "ride quality" unless you've added weight. Coil springs support the vehicle at a certain height. Shocks do the dampening. If you not happy with the ride then you need a different shock.... this is assuming that your not bottoming out at the top or bottom of the suspension travel. If your hitting the bumpers for some reason then you need durobumps or similar to soften the end of the stroke. I'll be first to admit that I'm not a professional and my advise is worth what you paid for it.

 

Why the heck is the caster negative. Someone let the lube kid do your alignment.

 

I have always wondered - can the caster be adjusted w/ stock UCAs?

 

No, and adjustable UCA oddly exist to allow proper alignment using the LCAs.

Chevy's are UCA align, and they suuuuuuuck in rust belt areas.