Alignment specs

Hey guys I have a 2nd gen Tacoma with a 3” coilover and JBA upper control arms. I read a thread that said +3 caster or something along that. What do you alignment gurus recommend?

 

Yep, the last few alignments I’ve always asked for:

0° Toe
0° Camber
3°+ Caster

I’m sure there are better reasons to go with maybe a slight negative camber and maybe a toe in or out, but the other Tacomaworld experts will have to chime in on that one.

As for caster I have always heard the same. When I ran 305s I asked for 3° and it ran well. With my current 315s I asked for closer to 4° caster and I absolutely love the way my truck drives on and off road. Personal experience is the more caster the better and I believe that is also the running trend on Tacomaworld.


(Ignore my before measurements as I had just replaced the LCAs and maxed out the caster)

 

I’m only running 275/70/17

 

I believe it’s all the same.

If it eases your mind, my 305/70R16s were less than 2% taller than your 275/70R17s, mine were just extra wide. If I were to do the alignment again (with those old tires) with the knowledge I have now I would have asked for more caster.

 

I have the 3” Toytec coilovers and jba uca’s has my alignment guy set caster at 4degrees no issues no rubbing. Running 285/70/17

 

for two tires that close calculators are not much of a tool. You could find a big difference between tire brands for the same size tire and then you can also make a difference with air pressure . Look up the specific tire and read the manufacturer's specs if its that critical to ya.

 

I don’t know how you do it... 3 days after alignment with plus 3 caster and any slight dip or unlevel pavement pulls the truck. Trucks seem to pull towards any bump.

 

Is this a recent development or something that occurred awhile back and your frustration is being expressed. If recent do you have the alignment sheet you can post?

 

I replaced lowers and welded TOtal chaos cam gussets on Thursday got the alignment Friday and it’s been dirveable just a little frustrating, everyone seems to recommend +3 caster but it’s been not good. Dont have alignment sheet, it’s in the truck but toe/camber were almost 0 and no diffirence side to side more then .2 and it was +3.2 caster driver and +3 passenger

 

Hmmm. You know its not uncommon to find that the LCA cam bolts were not adequately tightened. If so the cams will not fix the position and allow the wheels to control direction on every change of road surface. Maybe check those and very tight is not good enough. There torque spec is 100 ft.lb.

Another thing. The cam bolts are to be tightened only when the truck is at rest on its wheels.

Finally. The LCA bushings are not solid rubber but have an open web. They like to crack between the web with time and use and will cause the lower arms to similarly loose directional control but the rubber bushings at first inspection look fine. This may only be discover this with the arms off or very close examination.

 

I know they are torqued to 100 and brand new lowers/bushings

 

Isn't this typical with this much lift? Bump steer

 

Does the truck see offroad use?
I ordered that exact tire size and am curious if it will rub when flexing.

 

Since you mention it, I was actually thinking that may be a possibility but I was unsure.

To add to that theory, previously on my 305’s I had close to 3” of lift with roughly 3° caster (as well as seized lowers but that’s a different story) and I had a medium amount of bump steer but high pull due to road crown and road angles.

At the time I switched to 315’s I had roughly 2.5” of lift, new LCA stock replacements, and asked for closer to 4° caster and now my truck drives wonderfully with virtually no bump steer and it tracks straight.

I mostly thought it was my seized lowers being unable to stay in alignment but now I’m thinking otherwise.

 

Caster only affects how "willing" the steering wants to return to center on its own. Doesn't have major affect on how well it tracks over uneven surface.

With zero toe, it will want to follow every crease or dip in the road. Which is fine by me as tires should last longer. If wanting highway speed stability where it will hold straight with your knee or 'something else', then you should put in some slight toe out(correction-tow in) Thx later posts.

Camber is useless on trucks and should be zero or slightly negative. More negative camber is only a benefit when cornering at speeds 20-25 mph over the speed where the Tacoma has already rolled over.

And in ImMrCrash's specs sheet, I would have ask them to loosen the rear diff and try to straighten it. Just the play in the bolts can get rid of most of that rear thrust angle. Bang one side forward, the other side back and tighten bolts. Although not many techs are willing to do that. And mechanics hate doing alignments anyway so its luck of the draw. Especially if its a vehicle that requires shims to adjust caster/camber. You're most like getting toe only on those vehicles unless something is so far off it could be used in Vin diesel movie.

 

So I should go up to 4 instead of back to 2 caster? I want the best “highway ride”, I don’t do any serious off-roading other than driving through the farm fields and dirt/mud roads.

 

Rear might already be maxed out in that way. I was rear ended badly years ago and the repair shop did a shoddy job that caused all sorts of sketchy issues that I’ve since mostly fixed but it’s still not without its issues.

On the bright side I got 47k miles out of my last set of M/T tires and sold them with 5/32 left so I guess I did something right.

I personally would go for more caster if your uppers and lowers can do it and at this point I would even try what @scotkw recommended with the toe. I knew there were advantages to modifying toe but don’t know enough about it to offer a recommendation.

 

Caster does add a more stable feeling when you are driving especially at high speed. Think of bicycle forks they are on an angle similar to our upper and lower ball joints , thats why you can ride with no hands and the bike has a tendency to go straight , no different with our trucks with caster. How do you think the bike would ride if the forks were almost straight up and down same as our trucks with little caster . As for Toe in or out . Rear wheel drive vehicles normally have a slight toe in like maybe 1/16-3/32" on our trucks some go up to 1/8" . I have read many times front wheel drive cars get toed out and rear wheel street vehicles get toed in . the natural effects of driving them make the tires actually run pretty true to straight ahead when driven . Their are a couple threads on doing your own alignment . Read a few even if you don't intend on doing it you will get a bit of an education so you can pick out whats good and bad info you've received and the effects of each part of an alignment.

how-to-do-an-alignment-at-home.252256 this is also very educational as far as making our trucks drive good alignment-caster-clearance-and-driving-report-with-light-racing-ucas.158795

 

Actually, with rear wheel drive vehicles, you want a slight bit of toe in to give you stability on the road. Toe out will make it somewhat darty.