Camber Adjustment Quandary

[nationofzeros]

Interesting morning today as I took my NSX-R to a nearby wheel alignment shop to bring all the suspension settings back to factory - R standard

Once I had convinced the lads not to use the standard NA1 settings they had pulled up, everything went smoothly apart from caster adjustment which defeated them (and me)

The adjustment procedure is as shown/ attached below; the idea is to rotate a graduated adjustment cam which has a hole in it, presumably to accept a special socket with a protruding location pin, which would allow location, rotation & setup with a socket wrench or similar

Lacking such a tool (if indeed we were on the right lines) we made no progress, hence the caster angles are still out

Does anyone have experience of caster adjustment & how to go about it properly ??

Incidentally the mechanics, who spend more time than is healthy underneath 2nd hand cars, were astounded by the delicacy of the suspension & the all round condition of the underside - well done Honda!

Chris

[Silver Surfer]

You need the expertise of the the Kazmeister!
He did mine to perfection where others failed and said it was impossible (without damaging)...;)

SS

[NSXGB]

I second what SS says. I'm in a similar situation to you, have been to WIM twice to sort out the caster difference on mine with no luck (one side is 5 deg and the other 7 deg). There are apparently no special tools required and there is nothing that can seize to hamper the adjustment.
I'm going to see Kaz and visit his alignment center to hopefully nail this once and for all. . . Once my house move is out of the way. . .
Kaz will also take the time to get the settings as close as possible, not to just within tolerance.
Will let you know how it goes.

[Nick Graves]

Looks like a typical Honda Camber (sic) adjuster. They always seize onto the internal shaft, because Honda is too tight to lube them with Copper grease at the factory. I've a seized OSR on the S2000. We get round it by torturing the rubber bush, but I cannot dial in as much camber as I'd really like.

Now that's all steel/cast iron. Yours is a steel caster adjuster in an ally casting. Just add water and you've got electrolytic corrosion.

What I'd try is drowning the bugger in Plus Gas almost daily for a couple of weeks before the next alignment. With luck, it may soak in and you can break the corrosion with a club hammer. Good luck - it can cost £3,000 in new lower wishbones on an S2000, if they are all seized!

[NSXGB]

From what I understand, the caster adjustment is made by rotating the whole compliance pivot assembly. It is freed up by loosening the allen bolt at the top and two bolts at the bottom. Sounds simple. . . . As said, there are no parts that can seize.

Nick, you are talking camber, Chris is referring to caster. . .

[Kaz-kzukNA1]

Hi, Chris.

In order to adjust the Front Caster, you need to loosen the two nuts as in your procedure document attached to your post.

One is sitting just at the adjuster cam plate and the other one at the forward section of the compliance pivot.
You'll need to insert allen/hex key to rotate the adjuster cam but sometimes, I noticed that the hex hole for the allen/hex key was damaged like in the photo.
6334
You can still rotate the cam by applying some force at the edge of the plate.

If you want to understand the actual caster movement, first loosen the lock nut at the forward section of the compliance pivot but don't remove it completely.
Then, loosen the lock nut at the adjuster cam and remove it completely. The adjuster cam plate can now be removed from its position and you will see the oval shape hole which was hidden by the adjuster cam. If you apply some force to the suspension now, you will see how it moves during the caster adjustment.

By the way, depending on the equipment you are using, please carry out above test procedure before you start any preparations for the alignment setup.

As soon as you remove the caster adjustment cam plate, it will move the original position of your car and thus, you will need to go all the way back to the start line. All of your alignment data upto this point will also change resulting in another hours to be spent under the car….

Hope this will help.

Regards,
Kaz

[nationofzeros]

Thanks everyone & thanks Kaz for your excellent explanation - perhaps another job for the session we were talking about, will come back on this & thanks for the e-mail !

Currently the NSX-R's caster settings are

+8 deg 50' / +9deg 30'

and they should be

-8 deg 14' (I can only hope that the + / - sign conventions are actually both - in reality!

The rest of the setup is close to nominal NA1 NSX-R, namely

Front camber

-0deg 45' / -0deg 45'

Front toe

-2mm / -2mm (out)

Rear camber

-2deg / -2deg

Rear toe

+3mm / +3mm (in)

In this setup, the car is very 'lively' at the front & very susceptible to bump steer on anything but smooth road (track?), & also pulls to the left on bump steer, if you see what I mean. I know that the NSX-R is set up more aggressively than the standard NSX but still wonder if my wayward caster settings are having an effect...

Also I am running TOYO T1 Proxes which on previous experiences are not the most communicative re small changes in direction, at least until they are really warmed up

???

Chris

[michaelw]

Just to add, I had one siezed and one that was loose but sticky, until I tried to losten it further, it "Picked up" and that siezed solid too! All I can say is don't try and unseize the adjuster by winding it backwards and forwards; I had tried to lubricate it too.

My brother-in-law made up a steel replacement to the adjuster with a hex nut machined into it but he did say that you have to be very careful as it may well break the aluminium housing if you give it too much welly and I couldn't agree more. Let me know if you want more info or to borrow it.


Michael.

[markc]

Currently the NSX-R's caster settings are

+8 deg 50' / +9deg 30'

and they should be

-8 deg 14' (I can only hope that the + / - sign conventions are actually both - in reality!

In this setup, the car is very 'lively' at the front & very susceptible to bump steer on anything but smooth road (track?), & also pulls to the left on bump steer, if you see what I mean. I know that the NSX-R is set up more aggressively than the standard NSX but still wonder if my wayward caster settings are having an effect...

Chris

Hi Chris,

I wonder about the caster readings taken from your car and indeed the ones specified by Honda. It could be that the + & - readings are being substituted/reversed by either Honda with their spec or the alignment shop?

Almost all cars have some amount of positive caster ie the steering angle being inclined backwards (oxymoron?), to promote stability and self centering. The more positive the caster, the stronger the self centering effect will be as will be the steering weight as you wind on lock.

The negative figures quoted to you by HUK are unusual and in theory do not support the relatively heavy steering, especially on lock, that all models (manual and EPS) exhibit. I suspect they mean +8 degrees not -8 degrees, in which case your settings aren't too far out.

Also your current setting has more (positive) caster than it should have, which should have the effect of making it more stable and heavy rather than less so... odd. If in fact you do somehow have negative caster, that would explain the problem but I doubt the adjustment cam allows this even at it's most extreme setting. More likely the variation in caster you have between left and right could be causing the nervousness you describe?

As has been suggested you really need to get the caster settings equalised then align the rest of the chassis and see if that sorts it out.

Let us know how things develop :)

Cheers

Mark

[Kaz-kzukNA1]

.....

Front toe

-2mm / -2mm (out)

.....
Hi, Chris.
Just a matter of interest, did you increase the toe out for the Front?
The factory setup is -2.0mm +/-1.0mm for Front TOTAL Toe.

Probably, you were talking about Front Total Toe so it should have been written as ' -1mm / -1mm ' but just wanted to check after reading your comment of


....... In this setup, the car is very 'lively' at the front & very susceptible to bump steer on anything but smooth road (track?).....

If you are really running Front Toe per side as -2.0mm, then it is quite a lot and explains part of the comments you made.

There is no good/bad setup without knowing the full chassis package and driving/street/circuit conditions so please take this as just a personal interest.


Regards,
Kaz

[nationofzeros]

Thanks all & Kaz you are absolutely right ; the car should be running total toe of out 2.0mm and currently it is running out 2.0mm / side, so no wonder it is a bit nervy! (Same setting on both normal NSX & NSX-R)

Having checked on caster, I am pretty sure as Mark says that the actuals are + values (as per the standard NSX settings) and that the - signs on Honda's info sheet on suspension settings are an error. My caster is therefore a bit on the high side and not equal, but not miles out...

So armed with all this info, back to the garage for me. Am I correct to say that the way to adjust caster is to free off the two nuts on the compliance pivot & then to 'manhandle' the compliance pivot assembly physically from side to side until the angle is correct, lock the compliance pivot bolts down & then reset the camber & toe ?

Thanks - I never knew suspension setup held such joys!

Chris

[Nick Graves]

From what I understand, the caster adjustment is made by rotating the whole compliance pivot assembly. It is freed up by loosening the allen bolt at the top and two bolts at the bottom. Sounds simple. . . . As said, there are no parts that can seize.

Nick, you are talking camber, Chris is referring to caster. . .

Suggest you find out what sic means & re-read!

From the subsequent post, it looks like Honda has thought of the electrolytic seizure & provided an allen key hole to help turn the adjuster eccentric.