Setting Alignment and Ride Height - Dual Rate Coilover

[4XForOffroad]

I recently had my coilovers rebuilt by @DialedShockPrep a couple months ago and I am putting the truck on its own weight for the first time with it being a completed running driving vehicle. They’re 10” coilovers and I have 500 over 600 lb springs. The truck isn’t caged - it’s a dual purpose truck I’d like to drive to the desert, explore, and get back home with. After reading his 50% up/down travel for non-race trucks, I know I need to shoot for 5” of up and down travel on the shock shaft.

What I’m not sure about is preload on main vs. tender spring and reaching that ride height. I know he says something like 1-1.5” of preload on a spring is “good” (I remember screen shotting something like that but I can’t find it on my phone to fact check myself). But how do I pick the ratio of preload between coils to achieve the proper ride height? FWIW it’s a 4x4 A arm truck and it’s got 6” of up travel out of 16”total in the rear so I am addressing that with an HD leaf pack I have waiting around for it.

I’m ok with a smidge less than 50% up travel as I don’t mind a bit lower rode height overall but if that’s a bad idea, I don’t mind going with the 50% up.

 

[2012SVTSC]

So do you have a cross over nut on the coil over or just dual spring in a stack with no cross over?

If you dont have a cross over a 500 and 600 spring stacked is really a spring rate of about 275lbs/in.

Got a picture of your setup?

 

[DialedShockPrep]

I recently had my coilovers rebuilt by @DialedShockPrep a couple months ago and I am putting the truck on its own weight for the first time with it being a completed running driving vehicle. They’re 10” coilovers and I have 500 over 600 lb springs. The truck isn’t caged - it’s a dual purpose truck I’d like to drive to the desert, explore, and get back home with. After reading his 50% up/down travel for non-race trucks, I know I need to shoot for 5” of up and down travel on the shock shaft.

What I’m not sure about is preload on main vs. tender spring and reaching that ride height. I know he says something like 1-1.5” of preload on a spring is “good” (I remember screen shotting something like that but I can’t find it on my phone to fact check myself). But how do I pick the ratio of preload between coils to achieve the proper ride height? FWIW it’s a 4x4 A arm truck and it’s got 6” of up travel out of 16”total in the rear so I am addressing that with an HD leaf pack I have waiting around for it.

I’m ok with a smidge less than 50% up travel as I don’t mind a bit lower rode height overall but if that’s a bad idea, I don’t mind going with the 50% up.

On main and tender setups, you’ll set ride height with the crossover rings, and then droop the truck out and add 1” preload to the main preload collar. You can add more preload with the main collar, you just want to ensure that it won’t coil bind aka the slider stop rings lock out the slider before the upper coil binds up.
50-55% shaft at ride height is ideal for Prerunner play trucks, race applications i aim for 55-60% showing at ride height. This is also in reference to the bypass shafts since they are the shocks that are position sensitive, not just speed sensitive.
I have set up a ranger with 5” of shaft showing on the front of a beam truck, and it worked quite well, but would have been much better with more shaft showing at ride height.
It’s all a loose rule of thumb with these equations and there is definitely more to it than just sticking to those numbers but it will get you in the ballpark of having a good working truck for sure.

 

[4XForOffroad]

So do you have a cross over nut on the coil over or just dual spring in a stack with no cross over?

If you dont have a cross over a 500 and 600 spring stacked is really a spring rate of about 275lbs/in.

Got a picture of your setup?

My buddy set up the coilovers to where they were set in the picture. It’s sitting tall without an engine at the time. My bad I should have said there was a cross over nut.

On main and tender setups, you’ll set ride height with the crossover rings, and then droop the truck out and add 1” preload to the main preload collar. You can add more preload with the main collar, you just want to ensure that it won’t coil bind aka the slider stop rings lock out the slider before the upper coil binds up.
50-55% shaft at ride height is ideal for Prerunner play trucks, race applications i aim for 55-60% showing at ride height. This is also in reference to the bypass shafts since they are the shocks that are position sensitive, not just speed sensitive.
I have set up a ranger with 5” of shaft showing on the front of a beam truck, and it worked quite well, but would have been much better with more shaft showing at ride height.
It’s all a loose rule of thumb with these equations and there is definitely more to it than just sticking to those numbers but it will get you in the ballpark of having a good working truck for sure.

Is there a good tool you use for tightening the cross over nut? I think we used a thin pry bar or a big screwdriver and a mallet last time and it worked ok, but if there’s something good I’d like to try that as well.

Do I droop out the truck to spin the cross over nut while making adjustments for ride height?

You installed those yellow foam bump stops too but I assume the 5” is still measured directly from the rod end to the shock body?

I’m sure I’ll need to make a few adjustments / trips around the neighborhood getting ride height and alignment working out right. Pretty much everything on this truck has been put together all at once for the first time in 5+ years so it’ll be slow moving progress once I get it smogged and venture out little by little. Thank you for all that info. All the videos I found on YouTube were about selecting springs for dual coil setups instead of setting them for ride height although they were pretty informative other than missing that one thing.

 

[4XForOffroad]

I want to set my ride height and alignment before final assembly of hubs and axles so I can mess with the coilovers more easily. I had some delrin pucks made on SCS to block off the back of the spindles so I can drive a bit in 2wd as needed.

Before I even set it down on its own weight I’m trying to do an alignment off of the frame and front crossmember as references for my angles. I do this with my daily and my wife’s 4runner and they track straight with no abnormal tire wear. But this one’s giving me a little harder of a time since it’s not on its own weight or flat ground.

Originally I tried to set ride height using shock shaft alone, but I noticed the lowers were not the same angle to the frame so I switched to that as I figured that would give me equal ride height. The shocks are almost the same - 1/8” off from one side to the other so they’re still close to 5” up and down. Considering the spring seat is 3/8, I actually set ride height with 3/8” more up travel to get a full 5”.




To eliminate torque steer in 4x4, I’m trying to get caster and camber to match, but without being able to really set my toe, I spent last Saturday really chasing my tail as I couldn’t really verify the toe one either side and it was affecting my numbers quite a lot.

I’m thinking of making toe plates out of 3/16x1.75” angle iron and bolting them to the snout blocks using some washers to space them out from the caliper mounts and tie rod mount. Something like this but less professional lol.



The only thing I’m not sure about is when I read with an IFS vehicle, you need to have the centerline of the vehicle to set toe this way to make sure the wheels are actually pointed in line parallel with the frame. I don’t know but I was thinking of tying some twine between the LCA pivots and using that along with some twine going across to holes in my angle iron making sure everything is square to the centerline. The toe doesn’t have to be perfect, but I don’t want it so far off that I have to pull my coilovers and be adjusting caster and camber with my uppers if I don’t have to once I get everything to ride height with the coilovers. Does everything I mentioned make sense?