SPC LR UCA setting with 5100 @ 1.75"

[4OYOTER]

I did a lot of research before deciding on 5100s at 1.75" (OEM springs) with cornfed 1" spacer in rear. The main reason I did this over 2.5" with Daystar 1.5" spacer in rear was because I didn't want to need UCAs to get a good alignment. Well things sure haven't went as expected. I had my Toyota dealer do the alignment (first mistake?). I requested to please try to get as much caster as possible while still keeping camber in spec. They came back after 2+ hours says that +1.6 was the most caster possible and it was maxed out.

I later talked with the service manager who agreed to have his shop foreman take a look. I met with the foreman who immediately checked the lower eccentrics and said only one of them was maxed out, "so something is going on here". After another 2+ hours (on a different day) I inquire how things are going and the manager I was working with tells me to come out to the shop. My 4Runner is on the alignment rack with the foreman underneath. He clearly seems frustrated and asks if my wheels are aftermarket. I inform him they are OEM factory wheels from an FJ cruiser. (17" FJ steelies) He then goes on a spiel about how my wheels have a different offset and my tires are bigger (P285/70R17 Falken AT3W) so he can't go off of factory alignment specs and he is "starting all over on a custom alignment to get it to drive straight down the road". Then the spiel about how they are not an off-road shop and I can't expect them to get my alignment in spec on my off-road vehicle.

I smile and nod and say ok thank you, please just try to do the best you can. After a total of 5 hours that day, its finally done with caster barely in spec at +2.5. Unfortunately, I'm not really noticing a big difference at highway speeds. Steering still seems to feel a little loose and I find myself having to slightly counter steer often. (Wandering).

I'm guessing the next course of action is a set of new UCAs. At this point since my lower eccentrics are presumably now maxed out, should I set the LR UCAs at neutral D setting +2 caster, then have a knowledgeable alignment shop use lower eccentrics to fine tune? The reason I ask is because I am trying to avoid a BMC, but have no problems moving my front fender liners more forward. At this point I just had to move my fender liners slightly forward and remove the mud flap "hump". Would gaining 2 degrees of caster through LR UCAs actually move my wheel rearward? Maybe I would be better doing the E setting of just +1 caster?

Thanks for any help or guidance! Here is my most recent alignment report.

 

[wfo9]

You are in luck.....(since I live in the same area)

Go to Firestone at Arbor Walk, ask for John (the older guy who does offroad alignments). He is very familiar with the LR UCAs and will fix you up. I have no personal experience with him, but several friends who highly recommend him and that location. I would go by and schedule an appointment specifically with him.

Most people don't know how to adjust the LR UCAs... It's rare to find someone that does.

With your small lift you can probably start in the B +1.75 position.

 

[mrblah]

You shouldn't need UCA's for such a small lift, although it wouldn't hurt to get them.

With alignment, unless you have a specific problem you are trying to fix (like body mount rubbing), I'd settle as close to OEM specs as you can. There is no magic fix/number.

Positive caster will move the tires forward, and is a fix if you are having rubbing issues on the body mount. OEM UCA's don't have a lot of adjustability with caster. If you don't have rubbing on the body mount, then there is no reason to mess with caster.

Also, the farther you go from oem spec, the more squirrely the car will feel. When I messed with caster, it felt squirrely at first, but you get use to it.

As the previous poster suggested, take your car to a tire shop/alignment specialist, if you want specs like +4 caster. Also, if you are planning to do offroading or upgrading your suspension even further, I'd buy a lifetime alignment deal, because it will pay for itself in the long run.

5 hours sounds about right if you are looking for specific specs.

 

[wfo9]

You shouldn't need UCA's for such a small lift, although it wouldn't hurt to get them.

With alignment, unless you have a specific problem you are trying to fix (like body mount rubbing), I'd settle as close to OEM specs as you can. There is no magic fix/number.

Positive caster will move the tires forward, and is a fix if you are having rubbing issues on the body mount. OEM UCA's don't have a lot of adjustability with caster. If you don't have rubbing on the body mount, then there is no reason to mess with caster.

Also, the farther you go from oem spec, the more squirrely the car will feel. When I messed with caster, it felt squirrely at first, but you get use to it.

As the previous poster suggested, take your car to a tire shop/alignment specialist, if you want specs like +4 caster. Also, if you are planning to do offroading or upgrading your suspension even further, I'd buy a lifetime alignment deal, because it will pay for itself in the long run.

5 hours sounds about right if you are looking for specific specs.

He needs more caster... did you get the part about him saying it felt like it wandered.

It has been proven over and over again that the factory alignmenet specs are not enough for a lifted 5th gen. More caster is needed. He is hardly even in the factory spec at 2.5. +1 or 2 would make world of difference.

I've been around these trucks for a few years now. I have known many people, including myself who ran stock UCAs lifted. Funny thing though.. every single one of them (including myself) eventually went to aftermarket UCAs. That is not a coincidence. Granted, the amount of lift does make a difference. The bigger part is that all the trucks are different. No two trucks will align or drive the same. Even if you had all the exact same tires, wheels, suspension....That is why it is adjustable...

There is clear trend though... most will eventually get UCAs if they lift the truck.

I don't really care about the number... the machines all measure a little different. I just care about how it drives and the tire clearance. When you have both numbers and driving characteristics matching... a change is needed IMHO.

 

[mrblah]

I don't really care about the number... the machines all measure a little different. I just care about how it drives and the tire clearance. When you have both numbers and driving characteristics matching... a change is needed IMHO.

that's actually what I'm also trying to say. IF the car drives good, and there is no body rub, then everything is okay. If the car feels squirrely, give it some time, either the driver gets use to it, or he doesn't.


I wasn't arguing whether or not UCA's are beneficial or not, just whether he needs it in his particular case. Its not going to make his car feel less squirrely.

From my personal experience, messing with caster to clear my body mount, made my truck feel more squirrely in some driving situations, and I had to get use to it. My conclusion is the farther you go from OEM spec (even within its range), will affect how the car drives/feels. Again, YMMV.

Not trying to argue with you, just giving the OP more food for thought. Ever since I lifted my truck, stuck big ol tires on my truck, I've become best friends with my tire alignment guy........just letting the OP know my experiences.

 

[wfo9]

I wasn't arguing whether or not UCA's are beneficial or not, just whether he needs it in his particular case. Its not going to make his car feel less squirrely.

Not trying to argue either, but I think you are throwing out misleading info like above. More caster will make it feel better in a straight line with less tenancy to wander. It's just physics....

There is a point where too much caster causes another problem.. But when lifted you need close to max factory spec or a little more. Simple as that. There is a balance between too much and not enough.. but lifted and just barley factory... is not enough. This is not anything new at all. It's been proven many times over and is not some myth.

Granted it will never drive as good as many cars.. or maybe even not as good as a stock 5th gen.. But it can be very good.

 

[Simpleman74]

Im running 2.5"/2" and factory control arms with no issues

 

[wfo9]

Im running 2.5"/2" and factory control arms with no issues

Yep, that happens too. I was fine with factory control arms. Changed tires (same size, different profile) and the truck drove like crap. Had to get UCAs at that point. Then it drove perfect again.

Every truck and combo is different. For the OPs, all indicators seem to point to the fact that he should get UCAs. Now he could keep spending money on alignments and hope that he finds the magic settings. It's a choice. I think time is worth more than that...