Vintage Dunlop Camber/Castor/Kingpin Gauge how to use?

[Al Weyman]

I have had this old thing since the 70's and it was'nt new then but I never had any instructions with it and I desparately need to reset the alignment on one of my cars.

The camber part is obvious but the castor/kingpin is not so obvious. It has a grid in the box that you mark out chalk marks on the floor and turn the wheel outwards to the first line and I assume zero the gauge on the bubble then back inwards to the other line. When I do this with the guage in one position it gives a reading of 13, when I change it 90 degrees and reposition it it shows 2 degrees. Now would one of these be the kingpin setting (the first and when the scale is at right angles to the wheel i.e running front to back of the car) and the other one the castor (when the gauge is in line with the wheel spindle as per magnet gauges I have seen).

Anyone with long memories out there and know how to use this bit of kit which incidently is in tip top condition so should deliver the goods if I knew how to use it or better still have some printed instructions I would be happy to hear from you.

[Al Weyman]

Oh BTW I think its a K9 model but I will check later.

[Chris Y]

Originally Posted by Al Weyman

Oh BTW I think its a K9 model but I will check later.

?

[haggispeed]

I think Chris' K9 is the laser version
Al - it does sound very similar to the one I was given years ago (also without instructions) Mine is model CG3, never did figure out what that wire tempate / grid was for so have learnt something new
The thing I've never really been able to figure out is why the Camber scale and Castor scale are different ? since I thought the way to measure castor was to measure the camber at 20deg in then 20 out and subtract one from the other?

[Al Weyman]

I knew as soon as I posted that some wag would come back with that :-). Its why I remembered it actually.

I think looking at other guages you turn it 20 degrees aka the template (I only guessed this originally as there was crayon marks on it) zero the gauge then turn it the other way to take the reading. I have slacked my castor right off and the readings I am getting with the gauge in one position is 13 and in the other 2.

[GORDON STREETER]

Al I've got the camber part but not the rest of the kit. You can still get that part from Dunlop its now called CG4/5. The 4 being the main camber bit that hasn't realy changed for years, but I don't know as to whether the castor attachment (the 5 part) has.
Maybe the instructions for the later one will give a few pointers.
I personally use a Churchill camber/castor/tracking gauge that I found at a house clearance sale. It was brand new and nobody seemed to know what it was, I just happened to be driving by and as it was the end of the day I was given it as it was going to be chucked in the skip !!!
http://www.swge.co.uk/dunlop_wheel_a...mber_gauge.asp

[bdwoody]

is that what that is gordon i thought it was a fancy staple gun......!.'-]

[GORDON STREETER]

Sealey make a virtual copy of the Dunlop one, perhaps the instructions are similar.

[Al Weyman]

No its nothng like that Gordon as i said this thing is old. I will take a couple of pictures and post them up later so you can see what I mean.

[Al Weyman]

Doing a bit more research it appears castor is measured by the amount of camber change from lock to lock so i would guess my assumption how this thing works is correct i.e zero it on outward lock turn it to inward lock and re set the bubble to get the measurement. I would say 2 degrees with where it is set at currently looks about correct.

[Al Weyman]

Just checked it is the CG3 model. Dunno where I got K9 from!

[haggispeed]

The Dunlop CG3 is nothing like the CG4 at all. I'll take pics too next week and post. Would be good to reslove this Castor Camber scales thing finally

[Al Weyman]

Right I have set up the camber and castor and I think my assumption is correct unless anyone can enlighten me further as I have ended up with 2.25 degrees castor and 2.25 degrees camber which due to the restrictions on the suspension and keeping within the regs is about as much castor I can get and seems about right. I also get about 1 degree of camber gain at 20 degrees lock.


I recon this picture here shows the gauge set up for castor measurements.



I would say the next image is for measuring the King Pin Inclination.



Last picture shows the parts you slide the main body into to get camber measurments and is pretty self explanitory.

[GORDON STREETER]

Originally Posted by Al Weyman

Doing a bit more research it appears castor is measured by the amount of camber change from lock to lock so i would guess my assumption how this thing works is correct i.e zero it on outward lock turn it to inward lock and re set the bubble to get the measurement. I would say 2 degrees with where it is set at currently looks about correct.

That's how the Churchill one works . I'll sort you out a copy of the instructions next week .

[GORDON STREETER]

Haggispeed you're quite right its absolutely nothing like it !

[Al Weyman]

Thanx Gordon.

[haggispeed]

Yep - that's exactly the same as the one I have. So the thing that confuses me (believing that castor is measured as the change in camber angle from 20deg in to 20deg out) is why the two scales are different. You can just about see in Al's pic that the top scale says "Castor and King Pin" and has a scale of zero on the right and 20deg on the left. The scale below is very much smaller to show camber in and out. So which scale do you use when measuring the camber change to achieve the castor measurment ?
I'm impressed you got the clamp to fit the hub nut Al - mine always moves !
I think the best way to measure King Pin, if you need to is find a way of getting it directly onto the upright.

[Al Weyman]

As I see it forget the camber scale as that is only relevant when fitted to the upright bit in picture 3 and used as a conventional camber gauge. In picture one I would say thats the position for getting a castor measurement 20 degrees right and set the bubble level and take a reading 20 degrees the other way and rest the bubble level and take a 2nd reading, subtract one from the other for the castor. When set the other way as in picture 2 do the same thing but I recon this measures the kingpin inclination. In actual fact for the castor measurement I think you could use the gauge in camber mode and achieve the same results because as you can see I gained 1 degree and a tad camber gain at 20 degrees and lose 1 and a bit at minus 20 degrees therefore caster 2.25 degrees or there abouts as arrived at by the other method.