It's happening...

Generally speaking with a 2-2.5" lift a diff drop isn't really needed, nor is a carrier bearing drop. A sway bar drop I would do. I will do. That includes replacing the UCA. If you can get it to align and stay aligned at 2.5" then I wouldn't worry to much about UCA.

@bradwhitenikki I've read this same thing you just posted a few times. Can't remember exactly who authored it. But I've always wondered where the thousands to spend on geometry really stems from. Expecially with anything under 3".

 

The same principles apply for a 2.5" perhaps to a lesser extent.

 

Like what? UCA, diff, sway, carrier bearing drop. What else? That's not going to cost thousands of dollars unless you throw in tires and wheels as part of the cost....

 

Lesser extent meaning not doing half of what the post says except alignment..

Plenty of people running lifts without dif drops, with stock UCA, and everything else.

I'm sure the OP is aware of what he needs to do.

 

Hi. I authored it. Under 3 inches would likely not need thousands of dollars, though, all of the same considerations exist. Many people are not educated on suspension and driveline geometry and get sucked into nothing more than an appearance mod that ultimately makes their truck worse. I am looking out for the OP. I am trying to help the op get the information he needs. Never once have I seen a mainstream suspension company market a properly addressed lift kit. Sure they are out there, but people don't look too hard. They look for quick satisfaction at the lowest cost. I throw perspective into the mix.

 

I see where you are coming from. Good looking out.

 

Well said and thank you. I know it is important, as well, to try to match the u-joint angles on the 2 piece shaft as well, or one could have fighting u-joint velocities, resulting in strange, dynamic vibrations. Normally, like you've stated, a slight adjustment to the bracket height suffices. I am personally a fan of CV joints....

 

Yeah not all that is necessary. Especially if you're running anything below a 2.75" lift, you should be good without UCAs and diff drop. I have the 888 coils that got me about 3" and the only thing I needed was UCAs. No diff drop needed and no vibrations.

 

Do LCA's need to be replaced with a 3-inch lift? I looking at a 3-inch lift when I do.

 

Nope. Not necessary.

 

Sweet! That'll save me some $$ for sure

 

Heard the same, my matte gunmetal should be in stock in a week. According to Vin.

 

Your roll center will be a little high if you don't alter the control arm pickup points. The result is a potential jacking effect when cornering and very different roll centers from front to back.

 

A proper lift, which most people won't do, corrects the control arm arcs, roll center, camber gain, caster, and bump steer after a ride height adjustment. That is just the front... This is the right, but expensive way to do do it. This costs thousands as fabrication is not cheap. As I said most will never go this route as many don't even have a clue what the hell I am talking about anyway. most people, if they lean on the right shops, can make reasonable compromises such as control arm kits, diff adjustments, and alignments.

 

I did this on my 2012 ACLB 4X4 V6 MT. I hope it answers some of your questions.

https://www.tacomaworld.com/threads...d-884s-on-front-the-good-bad-and-ugly.381469/

 

Wow man, you are on a mission.
Before I read your explanation as to why you decided to post up in here, "I am looking out for the OP", I thought for sure you were just trying to flex your brain muscles.

So I got a couple of questions for you...
Is this your first Tacoma?
Your bring up "roll center" a few times in responses which confuses me. Typically when this topic comes up its usually on a forum where most are concerned with the handling characteristics on road. This is not to say there is no concern with the way our trucks handle, most of us try to dial in the alignment to prevent excessive tire wear, but as far as locating the center post lift front and rear why should I care? I'm not track racing my lifted truck any time soon.

Also you talk about control arm arch, you lost me there. Arch?? OR Angles following a lift. The rest is basically alignment lingo, most of which can be corrected (depending on lift height) by adjusting the lowers and or with the combination of after market UCAs specifically designed to help correct things like camber and caster.

 

Haha. Fair enough on all accounts. I am a bit of a suspension snob, but I am an educator as well.

The arcs of the control arms project centripetal force vectors (starting at the tire's contact patch) back at the truck as the vehicle is turning. The points of convergence of these vectors is the roll center. Ideally these vectors would be just below the center of gravity of the truck. Here is a visual for you: It is like when you run around a corner: you angle your legs and feet so that your center of gravity lines up with your roll center ( the forces that push back at some point on your body); causing a great cornering geometry for the body to not lean too much or tip over. We, humans, are very good at matching our roll centers with our centers of gravity.

The problem with vehicles (and Toyota did a great job with the stock suspension by the way) is that the roll center moves all over the place as the suspension cycles causing all kinds of strange dynamics that most people never know about. When your raise or lower a vehicle, you throw out all of the engineering, and very expensive simulation that went into optimizing the roll center dynamics.

I can get deep into this, but a picture is worth a 1000 works. I think this video may be helpful as a basic primer.

https://www.youtube.com/watch?v=kpjUPuk2cqE

 

I'm familiar with role center (not an expert), just never heard someone say "control arm arch".
I have to admit, I like to geek out on this stuff too so I can appreciate you bringing this to light, but I certainly wouldn't consider myself a suspension snob; there's always tons more for me to learn. As for this thread, I get bringing this up to a degree, but honestly and as I already mentioned, we are talking trucks here. Most on here want to achieve a lift for the purpose of clearance for off-roading. Some, as you already mentioned, are literally just doing the lift for looks, which I think is perfectly acceptable. IMO this is really no different than going out and buying a fancy sports car and using it for commuting back and forth to work. The car looks cool, handles great and is fast, but its by no means practical, comfortable and nor are some even all that safe.
Anyhow this stuff is cool to learn, but it shouldn't be the make or break factor in lifting ones (maybe yours) truck.

I have to ask again, is this your first Tacoma?
More specifically have you personally lifted a truck before? As much as I have learned through school/courses, actually getting my hands dirty has been most beneficial and rewarding for me. I find that what you learn from book, classroom, instructor lead course, doesn't always provide you with the answer in a real world setting. I also find that its almost impossible to end up with that perfect end result regardless of available funds, education or experience.

Look these trucks weren't perfect to begin with, after a lift you are certainly further from prefect, but I enjoy the project and the end result regardless. So if there's a catastrophic failure because of a modification I made or perhaps because of my own ignorance, I'll deal with it, but honestly I just don't see this happening after a 2.5" lift. Do you?

Now that this thread has been completely derailed ... no more out of me

 

Hi. To answer your question, this is my first Tacoma... not my first truck. I have designed, and built, suspension systems for off-road vehicles, road race vehicles, and drag racing (street to pro street classes) vehicles. My most famous design was used on a Jack Roush / Robert Yates drag racing car. I learned the practical stuff (hands on), then the theoreticals, then the practical... etc ... I pretty much know most of this stuff intuitively.

As far as your other inquiry, it is control arm "arcs", and arc intersections, than need to be considered. Roll center is an infinitely changing value. The control arm arcs dynamically dictate the ever moving roll center, and adjusting bolt pickup points to ride heights is very helpful to optimizing the gamut of roll center points.

 

Great class. Now onto lifting our Tacomas!



Just kidding Brad, well sort of. The engineering aspect is great stuff but for most of us all we want to know if it works or not.