Camber bolts, how do they work? Are they effective?

[Vova]

I recently found something on the net that could replace your original bolts with EZ-cam bolts to give you more camber-adjustability.



Now these bolts have a cam in the middle and this cam is supposed to bring the knuckle/hub more in- or outwards. How is it going to do that? I tried searching everything and could not get an anwser.

(see pic below for a similiar design as on our cars)
Our knuckle has a hole where the bolt goes into. The bolt than goes thru the strut-collar (whatever its name) to connect these two. Now the only way to get a angle on the sturt is if the bolt would offset the distance from the collar. How can it do that as the hole inside the knuckle doesn't touch the strut? The only way, is if the bolt head 2 cams right behind the head and at the end to act against the collar. Than the bolt would need to be smaller in diameter and also have a way to fill the the whole opening as the strut hole stays the same.

I don't get it , all I can read on the net is that they just easy replace your original bolts...how do they work?

[Vova]

Second, if this system would work by just replacing the bolt and by turning the cam it offsets distance which creates pos. or neg. camber...would it hold that camber effectivly? Would it not rotate when hitting a kerbstone on track or a small bump in the road?

Anyone used these? Expiriences?

Same question, just better formulated than mine I think:

http://bimmer.roadfly.com/bmw/forums...8879450-1.html

[Vova]

I think I got it. The Camber bolt is undersized, lets say the original is a 15mm, than the cam bolt is 13mm and the lobe adds another 2mm.

So when the lobe/cam is pointing to the top, verticly you fill the 15mm hole in the knuckle. However you can move the knucle horizontally nside or outside because there is 2mm of space.

Still its not all clear to me. If the lobe was pointing to the side, you would have no movement horizontally but you would have movement up and down. So if you were to adjust it would be between pointing straight at the top or pointing straight to the side.

Lets say its pointing straight to the side, now I have NO adjustment horizontally, however I can move the knuckle up and down 2mm as there is space of 1mm each side. How is that good??!! The only thing holding the nut place is the clamping force of the nut. If I was to hit a small bump the pneumatic effect would instantly shift the wheel, thus knuckle up. If I was to brake, the whole load is now pushing the bolt down and the only thing resisting is again the clamping force of the nut...no way its going to hold that!!

So if I understood this right (please feel free to correct me) these camber bolts are crap, especially for track or fast road driving..any driving I evne think. Only good for show cars that don't move!

Than again, this is the theoretical analysis, I wonder if practise prooves that they do work. However I have no trust in a undersized bolt with all the forces acting onthe small camlobe which isn't made of high grade titanium for the 20/30quid it costs!!

[Stiffler]

ive run a set of these for years, i put them in the top hole and set them to maximum (towards the wheel)

i think they can get upto 1.7 degrees camber so if you have lowered MORE than about 35mm they may not be enough to correct your camber.

mine have been fine for ages, and i check them the other week when i put some new pads in

there is no play in mine.

[Vova]

Ok, sound that practise may be different. Have you checked what the camber change is since you set it?

[Stiffler]

nope

i had slight scrubbing of the tyres on the inside edge so just fitted these on maximum and the tyres ware even now

mine is just a road car lowered 35mm

[skyshack]

The tab on the washer is a vital part of how it works, it locates the bolt in the hole in the strut.

You could possibly use rear camber bolts and weld some plates [ on the strut for the cam washers and head. See page FA-7 of manual.

[Vova]

So its just the little tiny pin sticking out of the washer that is holding the knuckle offset of the sturt? ALLL force is on that little pin?! How can that hold?

[Kev_L]

ive been running these for a few years now, my only concern is they do seem to be knocked out of alignment fairly easily by pot holes etc

[skyshack]

So its just the little tiny pin sticking out of the washer that is holding the knuckle offset of the sturt? ALL force is on that little pin?! How can that hold?

I've heard of people shearing the pin off, make sure the strut is free on knuckle before moving it. It's all clamped up by the bolt so friction between strut and knuckle is what holds it when driving.

Stock bolts just clamp and don't locate the strut to knuckle. You can get about 0.5° camber variation just from the slack fit of them.

It's how ALL bolts work unless "fitted", which means hole is reamed to exact size for bolt.

[Vova]

So the the strut-collar flanges clamp the knuckle inbetween them? Is that how it works? How can this clamping-friction resist so much force from the pneumatic movement of the knuckle when going over bumps?

So what you say is that the stock bolt is actually undersized for the knuckle already? Because when I took out mine there was no 'play' or 'slack' in them, I even had to tap them out to get them out but that could of been the rust...

[Vova]

Holy Moly, you are right, I went to a car engineer who told me the same! I also developed a good idea, I'm going to do it and if it works here I will post it!

[John Bennett]

So what you say is that the stock bolt is actually undersized for the knuckle already? Because when I took out mine there was no 'play' or 'slack' in them, I even had to tap them out to get them out but that could of been the rust...

I've not looked closely, but I bet it'll be the shock absorber holes that are oversized for the bolt, rather than the knuckle holes.

[Colwell]

I've had a set of whiteline ones on my car for 3 years no problems.

[Jon_H]

Just to give you some idea...

An Unbrako 12.9 grade M10 caphead has a max tightening torque of 77 Nm (assuming an unplated one). This, according to the catalogue, gives a clamping force of 45 700 N.

The coefficient of friction between two steel surfaces is probably about 0.1, maybe a bit more. I think the knuckle/strut is in double shear, so there are two pairs of surfaces being clamped.

Total friction force is therefore 45700 × 0.1 × 2 = ~9000 N, or about 0.9 tonnes, minimum, from one M10 bolt.

[Vova]

So I got this idea to increase camber without the use of camber bolts, what is your opinion and why?

If I file the strut's upper hole, where the upper bolt goes thru holding the knuckle, making it a cleft/slot, you can tilt the knuckle towards the in or outside, effectively adding/removing negative camber. This way (unlike with camber bolts) you maintain the added safety from the big bolt (= more clamping force) and you maintain the safety from the lower bolt that fits snug (well almost / manuf. tolerances) and counters up/down - left-right forces with its hole body.

I have talked about this Idea with a expirienced mechanic and engineer and with a chassis-restore mechanic and the last one actually told me they sometimes slot and than after aligning, they weld washers to the strut to "trick" the strut back into alignment. He also told me Volkswagen had slots like my idea in the past and so did some other cars but because of new manufacturing methods, designers believed tolerances were so little, no adjustment is needed anymore.

So slotting about 5mm to the right like in gay-pink between the horizontal lines keeping height the same is my idea.



What do you guys think?

[shane]

Good chance it'll move over time due to the constant pounding from the wheel/suspension. The cams work because they fix it in position, not relying on the clamping force of the bolts. I've ran camberbolts and they don't move. I've also ran something similar to what you have done and it moved. Uprated suspension puts to greater force on the Hub. Also don't believe every bodge a mechanic comes out with, he may not have seen the results later down the line.

[shane]

Also think of the forces put on it from hard cornering

[935Baby]

They works i have them. As i remeber, the trick is washer with nose...thats key part of it

I have bolts from USA, thats what i have.

http://www.courtesyparts.com/Merchan...uct_Code=81250

I have them on for quite long time in it holds camber well, and we have very shit roads here. Camber on front wheels even didnt change after my "ditch trip" Have to note that i am not racing with them on track so they dont see so heavy load, but i think it will be fine on track too.

Most funny part of adjusting camber on front wheels is that nissan states in service manual that you can adjust camber. But if you take stock bolts out you find out that they are not eccentric

[skyshack]

What do you guys think?

OK - only slot towards strut (someone had a strut bolt wear a slot outwards!). Adjustment is a bit hit and miss, you run risk of losing the position every time you slacken it off, so have to measure. Camber bolt washer has other big tab, so easy to see where it is set and move it in right direction. When in right place and torqued up put a single thick paint mark (bright and easy to see - yellow, red or white) on bolt head, washer and strut. If paint surface breaks something has moved. Then remember to look at it from time to time.