Arch here is what I did and why.
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Front
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- --
- -------
Adjust Caster and Camber (Upper Control Arm Bushings).
- - Full out on front camber adjustment then;
- - Rear camber adjustment until to spec as shown
in maintenance manual (don't have the numbers
with me but I think it was 1/2 degree on the passengers
and 3/4 degree on the drivers)
This provides the maximum caster available (per
discussion with Jim Bounds)
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- --
- ----------
Adjust Front Toe
- - 1/8" total toe out (1/16" per side)
If I recall correctly this is:
- - consistent with the manual
- - consistent with comments by Jim Bounds
I too was a little confused by "Toe Out" however
discussion with a number of front end specialists
(including my brother) confirmed it to be the norm
for front wheel drive. It becomes almost neutral when
pulling.
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- --
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Rear Alignment
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- --
- ------------
Rear Camber
I set both sides at 1/4 degree positive (top of wheel out)
Initially the manual called for 0 to 1/2 degree positive
Eventually GM updated the specifications to be 0 to 1 degree
positive
I suspect that GM found the original specification to be hard to
achieve (read expensive) especially with the allowable play
in the boggie arm bushings, however I believe the tighter spec
would probably be better if it can be achieved (I was able to).
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- --
- -------------
Rear Toe
I set mine at 1/8" total toe in (1/16" per side)
Initially the manual called for a range of +1/16" to -1/16" and the
diagram shows this to be total for both sides. This would
translate into 1/32" per side.
Eventually GM updated the specification to a range of +3/16" to
- - 3/16" (3/32" per side)
Again I believe that GM found this to be a difficult spec to achieve.
My boggie arm bushings are well within spec's. however I chose 1/16"
per side of because I believe that since the centerline of the tire is
outside the center line of the boggie arm bushings the tendancy would
be for the wheels to try to toe out slightly while rolling.
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- ---------------------
Rear Caster
Not applicable
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Thats what I did.
Of course before I started any of the above I replaced all the worn
parts front and rear and set the ride height.
Works for me although mine drove pretty good even when
everything was worn out.
The only thing I would change (if I could find them) would be to use
offset upper control arm bushings so that I could get more front
caster.
I believe this would help to resolve the only thing the steering on mine
is sensitive to........... ride height.
If I accidently leave the rear pumped up it has a tendancy to wander a
little.
HTH
Regards
Gary Zingle
1973 GMC 26 foot
- -------------------------------------------------------------------------=
- --
- --------
Front
- -------------------------------------------------------------------------=
- --
- -------
Adjust Caster and Camber (Upper Control Arm Bushings).
- - Full out on front camber adjustment then;
- - Rear camber adjustment until to spec as shown
in maintenance manual (don't have the numbers
with me but I think it was 1/2 degree on the passengers
and 3/4 degree on the drivers)
This provides the maximum caster available (per
discussion with Jim Bounds)
- -------------------------------------------------------------------------=
- --
- ----------
Adjust Front Toe
- - 1/8" total toe out (1/16" per side)
If I recall correctly this is:
- - consistent with the manual
- - consistent with comments by Jim Bounds
I too was a little confused by "Toe Out" however
discussion with a number of front end specialists
(including my brother) confirmed it to be the norm
for front wheel drive. It becomes almost neutral when
pulling.
- -------------------------------------------------------------------------=
- --
- ------------
Rear Alignment
- -------------------------------------------------------------------------=
- --
- ------------
Rear Camber
I set both sides at 1/4 degree positive (top of wheel out)
Initially the manual called for 0 to 1/2 degree positive
Eventually GM updated the specifications to be 0 to 1 degree
positive
I suspect that GM found the original specification to be hard to
achieve (read expensive) especially with the allowable play
in the boggie arm bushings, however I believe the tighter spec
would probably be better if it can be achieved (I was able to).
- -------------------------------------------------------------------------=
- --
- -------------
Rear Toe
I set mine at 1/8" total toe in (1/16" per side)
Initially the manual called for a range of +1/16" to -1/16" and the
diagram shows this to be total for both sides. This would
translate into 1/32" per side.
Eventually GM updated the specification to a range of +3/16" to
- - 3/16" (3/32" per side)
Again I believe that GM found this to be a difficult spec to achieve.
My boggie arm bushings are well within spec's. however I chose 1/16"
per side of because I believe that since the centerline of the tire is
outside the center line of the boggie arm bushings the tendancy would
be for the wheels to try to toe out slightly while rolling.
- -------------------------------------------------------------------------=
- --
- ---------------------
Rear Caster
Not applicable
- -------------------------------------------------------------------------=
- --
- ----------------------
Thats what I did.
Of course before I started any of the above I replaced all the worn
parts front and rear and set the ride height.
Works for me although mine drove pretty good even when
everything was worn out.
The only thing I would change (if I could find them) would be to use
offset upper control arm bushings so that I could get more front
caster.
I believe this would help to resolve the only thing the steering on mine
is sensitive to........... ride height.
If I accidently leave the rear pumped up it has a tendancy to wander a
little.
HTH
Regards
Gary Zingle
1973 GMC 26 foot
