Trouble with alignment

[luxstang]

When I went to get the front aligned we ran into a weird problem.

Let's start at the beginning: 

I replaced both upper and lower control arms (both MOOG) along with the idler arm a few weeks ago and waited for the weather to allow me to drive to the alignment shop.

I know the original numbers for the alignment suck, so I spent a lot of time online and fount that people tend to agree on 1-2.5 degrees of positive caster. 

Turns out mine had negative caster, handling was ok. Of course now the alignment was a little out of whack, so I gave them the numbers at the shop.

Here's the Problem:

It is impossible to set positive caster as the lower control arm won't clear the frame. At 1 degree positive the lower control arm will be pushed so far back that it rubs against the frame.

My car must have either negative caster or 0 degree at most unless you want to run into serious trouble.

Anyone else have this issue?

 

[JD79]

Hi Mike, maybe the guys from opentracker racing can give you some advise!

http://opentrackerracing.com/technical/

I've bought the MOOG CK series lower control arms myself but I can't give you any advise on alignment issues yet since they still need to be installed....

 

[luxstang]

Thanks JD. Those are the exact numbers I had.

 

[rocket366]

Here's the Problem:

It is impossible to set positive caster as the lower control arm won't clear the frame. At 1 degree positive the lower control arm will be pushed so far back that it rubs against the frame.

My car must have either negative caster or 0 degree at most unless you want to run into serious trouble.

Anyone else have this issue?

Just to be clear positive caster is the LCA forward of plum or verticle in relation to the UCA. 

Front   /

The car will be unstable and the steering wheel will not return to center without + Caster.

Paul

 

[midlife]

You can also add shims to the UCA to adjust caster. That's the old-school method that the 65/66 Mustangs used.

 

[luxstang]

Just to be clear positive caster is the LCA forward of plum or verticle in relation to the UCA. 

Front   /

The car will be unstable and the steering wheel will not return to center without + Caster.

Paul

YESSS, that's what I thought! But the machine in their shop says the opposite. Positive for them is setting the lower control arm further back. 

Coukd there be a difference in between US descriptions and European ones? I gotta look that up. 

I asked the guy at the shop "Doesn't positive mean forward?" And he told me no and showed me that when he put it forward the machine showed more and more negative caster. 

So, given the fact I'm not that great a mechanic, I thought I had misunderstood the concept. He's a professional and has a very expensive gadget to prove him right.

 

[Bentworker]

Something is getting lost in translation. 

You want that lower control arm as far twards the nose of the car.  With power steering you could go all the way up to +4 or 5 degrees caster.

 

[droptop73]

I dialed in a ton of caster (5-6*) in mine without issue.

 

[73pony]

Just to be clear positive caster is the LCA forward of plum or verticle in relation to the UCA. 

Front   /

The car will be unstable and the steering wheel will not return to center without + Caster.

Paul

YESSS, that's what I thought! But the machine in their shop says the opposite. Positive for them is setting the lower control arm further back. 

Coukd there be a difference in between US descriptions and European ones? I gotta look that up. 

I asked the guy at the shop "Doesn't positive mean forward?" And he told me no and showed me that when he put it forward the machine showed more and more negative caster. 

So, given the fact I'm not that great a mechanic, I thought I had misunderstood the concept. He's a professional and has a very expensive gadget to prove him right.

The guys are correct. Also from my experience, just because he is "a professional" and has a fancy machine doesn't make him good. I know this would be a tough find in Luxemburg or prob most of Europe but finding someone familiar with older technology in regards to alignment would go a long way.

 

[luxstang]

Got a new appointment tomorrow.

Like I said I saw the machine say towards the rear is plus and towards the front is minus!!

I looked it up and positive is forward here too. So it's their machine.

I replaced the eccentric washers and screens that got twisted during the setup and well give it another try tomorrow.

 

[midlife]

You're not in Australia where things are upside down and backwards, are you?

To my Aussie friends: if you feel insulted, please understand that I really meant the Kiwis...

 

[TommyK]

You want at least +2.5 assuming power steering.

 

[rocket366]

I didn't trust anyone to drive let alone align my car so I bought a Longacre camber/caster gauge

and turn plates and did it myself.

I know that aftermarket control arms are far from perfect. On one side I barely got 0 camber with

the LCA adjuster maxed out. You think they could get the C to C length right IMO!

MOST important thing is camber and caster MUST be equal side to side or it will pull.

Good Luck

Paul

 

[luxstang]

Ok, next try.

 

[jpaz]

I Love that yellow vert Lux! (I have a picture of it on my garage wall). Don't give up on her, you'll figure it out.

 

[73pony]

+1 your car is fantastic.

Also, let me know what you end up with for final alignment numbers and how it handles. I will be replacing several front suspension components (UCA, LCA, Tie Rods, Idler, Pitman, rebuilt quick ratio steering box, springs, etc) coming up here if the weather ever warms up so I will obviously need an alignment and I have seen suggested numbers all over the place.

 

[Bentworker]

Ok, next try.

SOOOOOOO... How did it turn out?

 

[73pony]

Ok, next try.

SOOOOOOO... How did it turn out?

Considering it is 1:00 am in Luxembourg I think we will have to wait until morning to find out.  :whistling:

 

[midlife]

Slacker!