Advice on front suspension

[96Qowner]

I just did an alignment check and my front end is a mess - WAY out of spec. Here are the numbers:

Left camber is -2.0, spec is -0.7Right camber is -1.3, spec is -0.7Left caster is 5.4, spec is 6.5Right caster is 5.4, spec is 6.5Left toe is 0.51, spec is 0.04Right toe is 0.49, spec is 0.04

I can shim the upper control arms for some of the camber, according to info in this thread:

zerothread?id=163690

But it looks like that will only correct by 0.8 degrees, and I need 1.3 degree correction on the left side. Jeff says shim kits with longer bolts are available for the 300zx and will fit the Q45.

And I still have excessive caster and toe problems. The alignment tech identified a bad "upper ball joint" on the left side - I assume he meant THE ball joint, since the Q only has one.

Advice? Can I assume worn parts are causing the misaligment? Should I replace the tie rod ends for the toe, for instance? Should I consider adjustable SPL parts? I recently replaced the struts and mounts, and sway bar end bushings.

The rear end is in good shape, except for the right toe, which reads 0.21, when it should be 0.09, left toe is 0.11.
Modified by 96Qowner at 2:57 PM 8/21/2007

[qship96]

I would take it to a 2nd shop to confirm those numbers first!

[96Qowner]

Heheh, no, this is a good shop with the latest Hunter equipment. The alignment tech was the company trainer. You can see the bad front camber with the naked eye. I'm running slightly short tires - Michelin Pilot 225/60/15s.

[cccpman]

upper links! Have you heard any squeaking or anything while hitting bumps coming from the suspension, if so its logical that it could be the upper links. I had VERY similar numbers when I had bad upper links

It might be worth a check, you cant really SEE whats wrong with them but you will hear it sooner or later. Depending on how you drive and how many miles you have on the car would also help determine if this could be the problem

Thats all I can think of because its the problem I had, sorry I cant be more help

[96Qowner]

The left upper link could be bad - it has over 50K miles on it, but my tech looked everything over when I had the struts replaced, and he didn't flag it. No noise or any other symptoms. The right one was noisy when I got the car at 147K and I replaced it then. I suppose, if I'm going to go to the trouble to shim them, I might consider SPL adjustables, instead.

I hope Wes chimes in - he's done a lot of suspension work.

You say you had similar numbers, cccpman? Which numbers - camber, caster, toe? Caster doesn't bother me a great deal - they're equal. But the toe is not a good thing. It's always had a sort of twitchy front end. It got better when I put Jeff's FSTB and new tension rod bushings on it, and the recent work helped, too. As Dennis and Brian are fond of reminding everyone - if you've never driven a G50 with perfect suspension, you don't have a baseline. If my camber and toe are off that much, it's no wonder it's twitchy. The tension rod bushings were really bad when I got to them. I wonder it they bent something.

[elwesso]

G50 front suspension is an art. Unless you have all adjustable stuff OR all brand new OEM stuff its never going to be right.... especially at 200k.

Replace your upper links, that should get your camber back to OK-ish ranges. The toe is easily adjustable with the tie rods, so dont worry about that, unless of course you're maxed out (EXTREMELY doubtful)... You can shim to perfection.

Be sure that you preload your strut brace before getting the alignment. meaning, jack the car up so the front wheels are off the ground, bolt the brace on securely, then lower the car....

Like you mentioned, caster isnt a real big issue, so long as its the same or CLOSE on each side. I run a lot of caster, much more than the spec which influences my camber gain. I'm still not entirely sure the quantitative effect caster has on camber gain but I intend to find out...

Really in all honesty, the specs dont look terrible. NEVER EVER EVER REPLACE ONLY ONE SIDE OF A VITAL SUSPENSION COMPONENT, unless of course its adjustable. If you dont kepe things EVEN your alignment will never be right.

If you're ever considering lowering the car, getting adjustable uppers may not be a bad idea. Theyre about $100 more/pair, but the bearings are replaceable for cheap.

[maxnix]

The left upper link could be bad - it has over 50K miles on it, but my tech looked everything over when I had the struts replaced, and he didn't flag it.

At 50K, it is worn unless you have been driving straight lines on a billiard table. Tech should have caught it. FSM has specifications. Even just age can degrade the rubber. Better check it all.

No more SPL adjustable links until......?

[96Qowner]

Thanks, guys - upper links, good, I can do that. Heck the right side has over 50K now too, I realize.

Ok, next issue. I have a rotational squeak on the right front wheel, which I assume is coming from the bearing. It's been with me for almost 20K miles. I've had my tech check it repeatedly and he couldn't detect any play in it - the alignment tech said the same. I've read NICO threads on the subject and they recommend replacing the entire knuckle instead of trying to press in another bearing.

I assume now would be a good time to do that, too? And should I think about doing both sides? What about the ball joint? Just replace it with a 300zx joint or get a used knuckle for that side? Um, Just exactly what is the knuckle? I'd be going through car-part.com for a used one.

[Q45tech]

Waiting too long beyond every 30k to replace upper links just means the third link bends along with the shock tower. The bushings in the lower traverse arm wear also.

We see lots of bad camber from old wrecks [even a curb hit] that were only PARTIALLY REPAIRED.

My bet is the third link and maybe king pin assembly are bent out of spec.

Shimming after a new upper link proves something is bent!

As brand new ride requires all new parts! EVERTHING!

[96Qowner]

Thanks, Dennis, I've been thinking lower side, too. So, what's the best way to attack the problem? Do the upper links and see what the new alignment shows? Sure, I could just replace everything, heheh, but money can always be used for other things, besides the Q.

Actually, if I do the third links and the uppers and the ball joint(s), I won't have much left to replace, will I? I suppose you mean new kingpin assemblies. I have a feeling those are kinda spendy.

[Edit] Arg! - new lower control arms are spendy - $270 a pop.
Modified by 96Qowner at 12:03 PM 8/22/2007

[elwesso]

You can get poly lower control arm bushings.....

[96Qowner]

You can get poly lower control arm bushings.....

Won't help if mine are bent ...

It looks like a knuckle is a "spindle" on car-part.com. Under $50, used. PopPop probably has 'em, too. What's another name for kingpin? Same thing or different? A used one could be a bad idea, though. After all, if I'm replacing them because mine are bent, there's no assurance the used ones aren't bent, right?

I guess I could just do the upper links first and see what the numbers look like, but it'd be nice to overlap labor with the balljoint and bearing issue. Balljoint looks easy, but if I'm gonna replace that right bearing, I might as well do it when the suspension is apart.

[Q45tech]

Used third links will all be bent out of spec, we've tried this a few times and only a new one will acheive oem nominal camber. Especially when you consider the costs of a few alignments to test results.

Half axxed used part repairs on suspension never get back to brand new.

[96Qowner]

Sorry, but I need a vocabulary lesson. Third link is ... lower control arm? Kingpin is spindle/knuckle?

[96Qowner]

Sorry, but I need a vocabulary lesson. Third link is ... lower control arm? Kingpin is spindle/knuckle?

Darn, and it looked such an easy question to answer ...

[elwesso]

the 3rd link is the "upright". The top of it bolts to the upper link, the bottom of it houses the kingpin which attaches to the knuckle.

[96Qowner]

Thanks, Wes.

Joe's online illustrations and the FSM illustrations don't match up. On Joe's site, the third link is labeled "steering knuckle", which it clearly isn't. Hard to price and order parts when they're called different things.

Looks like the kingpin is separate from the knuckle and easily replaced, yes? Do we suppose that's what the alignment tech was referring to when he called it the "upper ball joint"?

[elwesso]

when you buy a new 3rd link it comes with a new kingpin already installed... usually that is the way to go, sort of a 2-fer especially in your situation.

[96Qowner]

Yep, it looks like upper links and third links will do it for me. Roughly $400 in parts. Here's an old thread covering the same subject. Apparently Joe calls the third link assembly a "complete knuckle extension":

zerothread?id=195069

Still don't know where my wheel squeak is coming from. This morning, it whistled for awhile at highway speeds. When I'd engage the brakes it would stop abruptly - start again immediately after releasing the brakes. It would stop briefly when I'd rock the wheel left and right. Then it just quit. The squeak has been there for a long time - the whistling just started happening in the last few thousand miles, and has only happened a few times.

Thanks for everyone's advice.