Novice DIY suspension install?

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Hey All, especially the mechanics among us..

I have a 2021 4Runner and the next mod I'm considering is a suspension upgrade. My goal is to do as much of my rig build myself as possible. This isn't so much to save money but for the fun and learning experience.

I'm reasonably handy and have a decent (if mostly theoretical) understanding of automotive concepts, but I have minimal hands-on experience actually wrenching on cars. Is attempting a DIY suspension install myself a sane thing to do, or do folks feel this is best left to the pros? As much as I'd like to learn, safety and reliability are much more important to me, and the consequences of a botched suspension install seem... unpleasant. My instinct is to have this particular mod done at a shop, but I'm open to encouragement to give it a go. Any tips or insights from others who've done this would of course be appreciated :)

Thanks!
Kris

 

[smritte]

First question is, what exactly are you replacing and with what?

Strut spacer to level the vehicle? Alignment after.
Full adjustable strut, longer control arms, knuckles......? Alignment after and a few more tools.
Are you using bushings and ball joints or heims and uniball?

Any of the above, done by a "pro" doesn't mean done correctly. My comment is based on myself doing this professionally over my lifetime. All if your suspension is just nuts and bolts, nothing too difficult. If your new strut comes disassembled, you need a spring compressor to assemble it. If your using bushings in your arms, the arms must sit at "ride height" when final torque is applied. Put a jack under the lower arm, raise until the vehicle body moves and torque the arms. If you don't, the bushings will twist when you put the car back on the ground and tear them. This is something most "Pro's" don't do or don't know about.

When everything is done, align it. If you research this, you find its not too hard to do in your driveway. Simple is just paying someone to do it. Some suspension kits need diffrent techniques to properly align. Again...most alignment shops can put it back to spec but some people are intimidated when they see a modified vehicle.

Don't forget, depending on what parts you install, its entirely possible the vehicle will require a diffrent inspection technique and performance parts tend to have a shorter lifespan even street driven. I use heims and Uni ball in my suspensions. They require regular inspections where as I can have bushings and ball joints that don't require too much until they see a bunch of miles.

Whether or not you do the install, learn what you have and learn how to inspect it. None of its too difficult.

 

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Thanks, these are exactly the considerations

I haven't picked a specific package yet, but I'm primarily looking to level and for a moderate lift (maybe 3" or so on the front; less on the rear).

Something like the Eibach 2.0 coilover kit here: Eibach Pro Coilover Lift Kit 5th Gen 4Runner (2010+)
I'm also considering the OME BP-51s which seem to be very well regarded, but perhaps overkill for my expected use.

I suppose I might be putting the cart before the horse somewhat :) It occurs to me that I probably have more to learn about the ins and outs of suspension systems, tradeoffs, etc.

I have a reasonable understanding of ride height, adjustability (bound vs rebound vs both), spring weight, travel and heat dissipation (external reservoirs), why they matter, and how to decide what I need.

I definitely have more to learn about reliability tradeoffs and failure modes.

I wasn't even aware that there was a decision to be made on things like ball joints vs heim vs uniball - before now I'd never even heard of a heim joint which sent me down a fun internet rabbit hole :) Based on some basic internet research, it seems like ball joints are sealed and thus easier to maintain, while heims/uniballs offer more articulation/range of motion at the expense of exposure to the elements. This is probably an over simplification..

I understand that after a certain point, the stock UCAs can no longer maintain proper geometry through the suspension's range of travel, but it's not clear to me what that point is or how to know when you've hit it.

I suppose that's just part of the iterative process of dialing in a setup :)

I'm just musing at this point, but your response have given me a lot to chew on, so thanks! If there are any other components or considerations that come to mind, I'd love to hear them..

Kris

 

[smritte]

it seems like ball joints are sealed and thus easier to maintain, while heims/uniballs offer more articulation/range of motion at the expense of exposure to the elements. This is probably an over simplification..

Nope, spot on. More travel, no binding/tearing, less longevity.

I understand that after a certain point, the stock UCAs can no longer maintain proper geometry through the suspension's range of travel, but it's not clear to me what that point is or how to know when you've hit it.

Your suspension is a short/long arm type. As long as the range of motion stays in the range its built for, you cant ask for better. The down side is, outside of that range, the upper arm tilts the tire in or out which can bind the ball joint and cause geometry issues. The upper control arm controls the knuckle position. The other issue here is the ball joints are designed to be somewhat centered straight up or down. If you lift it too much, the UCA is at an angle and the ball joint push's into the side of it's cup. This is where Uni ball comes in.

Eibach makes a good spring and strut. The upper arms are probably slightly longer to fix the geometry. I have used the total chaos parts and can say those are good quality (I saw the option in your link). I believe they use Uni ball but you would want to contact them to be sure. In a non stock set up, I would prefer that. You can wear ball joints fast with too much angle.