caster problem

[rubbinsracin]

So we went to change the spindle before the first race this year because we had found a crack in the snout and we replaced it with one identical to the one that was on it and we went to set the caster and no matter what we did we couldn't get to 4* caster on the right front. Could only get to 2.5* no matter what we did. What will having less caster do to the handeling?

[AmickRacing]

Wouldn't hurt to check the ball joints also. Sometimes they can take a good pounding and not bend, but other times they can tweak after a little bump.

Castor isn't quite as important as camber, but it's still a part of what makes the front end work better. Make sure you still have castor split (more caster on the RF than the LF), you'll probably be able to get by for a week or 2 if you have to, but continue to look for the issue. Might be a bent strut tube/lower also.

Btw, the way I test ball joints that aren't obviously bent is chuck a drill up on them. Usually takes a pretty good sized chuck to get on the lower ball joint, or a lathe. Turn it slow, you'll know right away if it's bent or not. Works better on the low friction ball joints, if they are the standard ball joint, you better hang on tight.

[Renegade Cust Susp]

I have also seen spindles that are not reemed at the proper taper for the ball joint or spindles that are tweaked have a hard time getting proper numbers.

[jedclampit]

Top balljoint is behind the lower when viewed from above correct?
One piece lowers? New spindle?

[Dirtrunner35]

Yes upper ball joint behind lower for positive caster, like a bicycle fork.

[racer241]

had the same problem last night with two different cars actually, are they mastersbilt? our masters are always right on the edge of making the caster we want. had to slot the upper a arms and slide them back to get our numbers. was a pain but it did work

[Matt49]

We also run a MasterSbilt Smackdown and we've had the same problem on the RF since running the one-piece lowers. We can't get enough caster in the RF.
That adjuster at the front of the lower does nothing but put everything in a bind. I'm no engineer but a triangle with one angle that won't move (the angle at the ball joint on the one piece lower) is a RIGID structure and all you are doing by adjusting that "turnbuckle" deal is putting everything in a bind.
We've started using slotted uppers with the slugs in them to get the caster where we want it.

[35racing]

Good to hear Im not alone, Same issues on my Smackdown car. we also used the one piece lowers and wondered how they could possibly work with nothing to give upon adjusting them. Found out the hard way when you clip something with the LF tire hard enough it will pull the bolt right through the front cross member where the strut tubes bolt. I would imagine due to the major preload that strut tube has in it....

We also have went to slotting the upper A arms which is probably an ok deal but may as well just go back to the two piece lowers and make life easy.

[huckleberry_hound]

What is the proper way to check castor??

[rubbinsracin]

probably another method, but we just use the all in one caster/camber gauge from longacre. bolts to the hub, turn, level, turn level then you get your reading.

[huckleberry_hound]

Can u explain that further,,,,do u zero the gauge then turn like 20 dgrees one way and so forth ?

[rubbinsracin]

instead of me trying to explain it like a blithering idiot, here are the exact instructions we use for our model of gauge.

http://www.longacreracing.com/instru...xt/78250PI.pdf

[AmickRacing]

Not saying it's right, but here's how I do it.

Make sure the toe is set close.
Check camber
Turn back 20 deg (when doing right side, turn to the right 1st; left side, turn left 1st)
Zero the gauge, I use the old school bubble style fwiw
turn 20 deg the opposite way and read the caster.

If you change camber or caster, double check the other after you make the changes.

[sj valley dave]

Amick, that is exactly how we do it, but according to GRT, you should set caster before camber as caster can affect camber.....other than that, that is how we do it...turn it until the angles corners on the gauge are parallel to the body re set to zero then turn back the other way till the angle is parallel again..

[Leftterns]

Agree with the procedure. You like + 4 degrees on the right?

[sj valley dave]

We like to run a big split +5* on the Rf and +1- 1 1/2* on left front...

[Leftterns]

Doesn't it depend on the track banking and how hard you feel like working against the positive RS caster if moving the wheel to the right?

The car pulls in the direction of positive camber and negative caster.

Not much help if you can only squeeze +2.5 RS degrees though.

[drtrkr244]

One of the new trends is to run the same caster on both sides since you are turning the wheel in both directions.

I was told this by one of the top drivers in the country.

I am trying this now on one of my customers cars and I dont see any negatives to not run it.

[DirtyDriverII]

I have also watched people have issues if they do not have some sort of turnplates or at least a good non stick surface (false readings). Still a better idea to use the slotted uppers; use the lower strut to set the lead in the car.

[HEAVY DUTY]

So we went to change the spindle before the first race this year because we had found a crack in the snout and we replaced it with one identical to the one that was on it and we went to set the caster and no matter what we did we couldn't get to 4* caster on the right front. Could only get to 2.5* no matter what we did. What will having less caster do to the handeling?

Did you change the a arms or balljoints.The spindle itself couldnt have changed the caster. The caster is a straight line thru the balljoint centers.If the spindle was a different height it could change caster by moving the balljoints closer together or farther apart.A spindle with a different inclination can change camber a bunch but not caster. I believe I would be looking at a frames.