I will give it a try. Just talking about tow in. I don't have the specks
for the 505 anymore so I will use the 405 as a example. The 405 speck from
Haynes is 1mm plus or minus .5 mm that means that the distance from edge
of left front rim to edge of right front rim farthermost forward should be
.040 in smaller then the same measurement at the part of the rim
farthermost back (when looking at the left front wheel 3 o'clock should be
in .04 from 9 o'clock.)
Our range is from .5 to 1.5 mm or about .02 to .06. or very roughly about
1/32 to 1/16 in. There are other places we can measure tow in. One handy
place is at the fat part of the tire. Another place is at the tread, or
outside of the tire.
On my 405 the outside of the rim is 15 in, the fat part of the tire is 19
in and the outside dia of the tire is 23 in.
by scaling the specks we get
rim 15 in .40
fat part 19 .056
outside of tire 23 .062
Hanes has a good section on how to get the car ready to measure. To sum
up. bounce the car and Then roll it 4 ft. to relax the suspension. then
measure, then adjust, then bounce and roll again. then measure again. (The
alignment machines put the wheel on a small turntable/slide so it can move
around without moving the car.)
Now how do you measure. It is hard to measure to the rim because it is
recessed. You can build a jig to do this. (I built one from a section of
conduit, scrap wood, and some screws.) It needs to have one arm and pointer
on each end to touch the rim and the arm needs to be able to be pulled back
(to move from front to back of the rim) and return to the same spot. (some
sort of sliding and then locking collar. I found this a pain in the neck
to use.
The easy way is with the string. But you must have the same size and brand
tires on all wheels and the car must have the same track front and rear.
The 505 doesn't but you can make a couple of shims out of wood to
compensate. Front 59.1 Rear 57.3 make two shims .9 in thick (about 7/8)
Tie the string to something behind the car. (I used the trailer hitch.)
Wrap the string around the back of the rear tire 1/2 way up. pull it up
past the front tire and tie it to something heavy setting on the floor but
1/2 way up the tire (a tool box) insert the shim between the fat part of
the rear tire and the string and then move the front anchor and the
steering wheel until the string just touches the front and back of the
tire. Then do the same on the other side (but don't move the wheel) Move
the string until it just touches the fat part at the back of the front
tire. There should be a gap between the front part of the tire and the
string. that gap is your tow in. If you can touch the string to the front
and there is a gap at the back part of the front tire you have tow out.
The best way is to jack up each front wheel. drive a nail through a block
of wood and sharpen the point. hold the wood on the floor and rotate the
tire scribing a fine line in the tire.
Put the car down, bounce it, roll it, and then measure to the scribed line
ahead and behind the front wheel subtract the back from the front and that
is your tow in. (remember the ratios)
This method is very accurate and is as good as any professional job, but
lots of jacking, pushing, laying on the floor etc.
Yup. lots of work, but you know that the guy
1. Used the specks for YOUR car.
2. Set it as Tow in not tow out.
3. If it was way out, adjusted both tie rods, not just one.
4. Tightened the jam nuts.
5. Drove the car a half mile and checked it again.
+---------------------------------------------------+
"Lo, this only have I found, that God hath made man
upright;but they have sought out many inventions."
Ecclesiastes 7:29
Frank DeWitt | mailto:frank@lbpinc.com
Mechanical Design | Phone: 716 624 3052
LBP INC. | Fax 716 624 1038
2365 Cox Rd. |
Bloomfield NY 14469 |Web http://www.lbpinc.com