The handbbok for my Disco gives a toe-out tolerance measurement from 1.2 to
2.44mm. I am quite happy working in degrees and minutes, but have no idea where I should be taking the above measurement from. Could some kind person explain it to me, or direct me to a web page that does.Thanks, John
Measurement is the difference between the track measured at the front and back of the front wheel on the tyre tread. The easiest way to do it is to jack up the front, spin each wheel holding a fine piece of chalk against the tread to give a line to measure from, then measure at the front and back of the wheels (preferably after putting weight back on the wheels) - easier if you make up a rod or pole with two point sticking out from it, one adjustable. JD
Thank you.
What you are trying to measure is illustrated here:
I just use the closest points on the insides of the tyres at axle height to avoid problems with damaged rims.
A simple extending rod is all that is needed (or fixed length and something to measure short extensions therefrom) - you may need to have the ends 'bent up' to get round roll bars etc..
Don't get hung up by what you're doing - all that you are measuring is the difference in the defined length at the back and front of the wheels. Make your bar to fit to the rear of the wheels, move to the front and check the gap. The difference (your 1.2 to 2.4 mm) is wide enough to be gauged visually.
On or around Fri, 22 Sep 2006 07:32:19 +1000, JD enlightened us thusly:
in practical terms, it's most often measured on the wheel rims. Generally find parallel works well on LRs, but I don't know if that's still true on recent ones (disco III etc).
which reminds me, must tweak Edward's tracking a tad - it feels a bit toed out. that and adjust the brakes.
Thanks to all, have now made a gauge out of wood and a wire coathanger, just waiting for the rain to stop now.
John
Which Disco? My 300 Tdi is supposed to be parallel. The 200 Tdi was said to be 1-2mm toe out. TonyB
|| I just use the closest points on the insides of the tyres at axle || height to avoid problems with damaged rims.
Funny that, I always use the insides of the rims (assuming undamaged) to avoid problems with variations in the tyre wall! In practice, the difference (radial distance from the hub) is insignificant - what is more important is to use the same fixed point in all four locations you measure (left/right, front/rear of wheel).
Don't forget to roll the vehicle forwards a few feet before you measure so that play in the balljoints etc is taken up, and make sure the wheels are pointing dead ahead - if they are to left or right, Mr Ackermann will make sure your measurements are in vain.
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