New MOOG control arms = FUBAR castor

1035 Views 6 Replies 3 Participants Last post by itdood, Dec 1, 2005

itdood

Discussion Starter · Nov 26, 2005

Hi Folks,

I just had to replace both front lower control arms on a 95 TSi (the straight control arm).

Afterwards, my wheels won't center up like they used to. Centering force is less, and as I turn the wheel more, centering force will decrease. When I have the wheel full lock from a stop, there is no centering forace at all.

When I'm in reverse, centering force is actually stronger!!!

I haven't been to an alignment yet because I figure centering force is the result of castor, and castor isn't even adjustable.

I replaced the originals with MOOG parts. The only other od thing I can think of is that I had the right-pull TSB done when the car was new back in 95. That changed the comnpression arms to compensate for the right pull, giving the left more castor.

Thanks in advance if anyone has advice or expereince with this!

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cbilmer

· #2 · Nov 26, 2005

I have a passenger side moog arm and never had a problem. Even without getting an alignment.... (which i probably need).

Is it possible you got a bad one? Did you match it up with the stock to look for differences?

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itdood

Discussion Starter · #3 · Nov 27, 2005

cbilmer said:
I have a passenger side moog arm and never had a problem. Even without getting an alignment.... (which i probably need).

Is it possible you got a bad one? Did you match it up with the stock to look for differences?

we compared with the originals, everything seemed to line up. My brother-in-law owns a shop and we did the work on one of his lifts. I did both arms (both were loose - right side was really bad), which are different part #s. They weren't labled left or right, so we called the parts store to make sure.

At first I thought maybe I had them on backwards, so I switched them last night, same results. I noticed there wasn't the best fit on the strut fork when I did that but it wasn't bad enough to prevenet me from getting them on there. I guess that's why they are different part numbers. They look execatly alike. One cost $1.50 more than the other

So I'm going to swith them back tomorrow, fun fun fun!!

Nothing is ever easy with this car

I'll post back if I find out anything.

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jtmcinder

· #4 · Nov 28, 2005

itdood said:
The only other od thing I can think of is that I had the right-pull TSB done when the car was new back in 95. That changed the comnpression arms to compensate for the right pull, giving the left more castor.

Actually, the TSB for early 2Gs is to delete caster from the left. Those of us who race later 2Gs undo this change because we want as much caster as possible and it's nicer when the two sides match.

- Jtoby

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itdood

Discussion Starter · #5 · Nov 28, 2005

jtmcinder said:
Actually, the TSB for early 2Gs is to delete caster from the left. Those of us who race later 2Gs undo this change because we want as much caster as possible and it's nicer when the two sides match.

- Jtoby

Got it, thanks for clarifying!

I just pulled an alignment I had done back in 2001,

LF is 3.1^
RF is 5.0^

I didn't realize that castor actually is +, so it makes sense that by deleting some you would increase the centering force on that side (get rid of right pull)? I always thought castor was negative to begin with, that what I thought centered the wheels, like on a shopping cart.

It would be bice if we could use camber/castor plates, but from what I can tell, that's impossible on a 2g because of the upper wishbone?

How are you adjusting it?

Thanks for your help!

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jtmcinder

· #6 · Nov 28, 2005

Positive caster causes push, so they deleted left caster to reduce the push from the left towards the right. Afterwards, the car tracked straighter on roads with high centers.

You undo the TSB mod (and, thereby, equalize caster) by flipping the bushing on the inboard end of the left compression arm. That will get you about 4.5* on both sides.

- Jtoby

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itdood

Discussion Starter · #7 · Dec 1, 2005

Update

Hi Folks,

Finally got an alignment and castor is fine, I jumped to a conclusion.
It's now:

LF is 3.2^
RF is 4.9^

See my post above for what I had back in 2001, it really didn't change at all.

Toe was messed up. The car went from a little bit negative toe to high postive toe and that really messed up the feel of the car. I wouldn't have thought changing the lower control arm would mess that up because they are supposed to be exactly the same. Live and learn.

I usually have about -0.02^ or so.

I went from that to

LF = +0.57^
RF = +0.85^

That made the car pull slightly to the right, made the steering feel sloppy because the centering forces were not as strong. The car would wander at slower speeds. When I would turn the wheel to full lock when stopped, then start moving, the wheel would lock harder instead of trying to center. Really made me think it was castor but as usual, my view on the world was wrong and I had to learn the hard way.

The toe now is

LF = +0.09^
RF = +0.02^

So now there's a very slight tendency to lead left. The steering is centering much better but not as much as I'm used to. I like a stronger centering force. When I turn full lock and start moving, the wheel will center now.

I bought the one year alignment program from NTB. I think I'll just wait for the new control arms to break in and make sure everything is still tight then bring it back in and ask them to get the toe closer to 0, if not able, make it a bit negative.

Thanks for the help folks!!!!

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