Testing caster

gary j zingle

New member
Jun 5, 1999
326
0
0
"It really amazes me how you guys can jump on an idea like this and
possibly
come to the wrong conclusion. Arch you lowered your coaches back end and
said drove better and when you raised it, it drove "squirrely". You came =
to
this conclusion without ever knowing if the castor and camber of the fron=
t
was set correctly or not, and whether the ride height was set correctly.
YOU
can conclude what you did ONLY is everything in the suspension was set
correctly to begin with."

While I would agree that perfect alignment before testing would be
best, the test is still valid.

In effect when Arch lowered the back of the coach he increased the
amount of caster. While the test was conducted in advance of
completion of the alignment the same test can be conducted
by anyone who believes their coach is properly aligned.

Caster can be accidentally adjusted through bad ride height.
Intentially adjusting ride height with the air to test changes
in caster is valid.

When I discussed caster with Jim Bounds he advised that more caster
is good. Helps to keep the coach going straight. I believe the number
was "even as much as 5 degrees".

When my alignment was done I could only get 1 1/2 degrees of caster
on the one side and 2 degrees on the other. Personally I would like to
get more.

I don't think anyone will get much more than the 2 degrees unless
camber is wrong or the offset bushings are used.

The only down side to lots of caster is that it makes it more difficult t=
o
initiate a turn.

Turning is no problem. I have power steering and don't run my coach
on a slalom coarse.

Wind and ruts, going straight and getting the suspension correctly
adjusted given the lack of dedicated caster adjustment is the issue.

Hopefully this provides some insight as to the intent of the test.

Regards

Gary Zingle
1973 GMC 26 foot
 
Stupid Question # ??? If lowering the rear end improves steering why
not set rear height control 1 " or so lower. I saw a gmc on Oregon
coast last summer that almost looked like a lowrider. In fact he came
over to my campsite and asked why I had mine raised up so high. Of
course he did'nt know much about GMCs as he was Oregon regional sales rep
for another brand of motorhome. He was lavish in praise of gmc quality
when compared to brand he sold. He called his plywood boxes. By the
way, completed installation of new steering gearbox yesterday. Have'nt
gave it real test with toad attached yet but did drive it a couple of
miles and must say steering is much improved. Now have to turn steering
wheel 1/2 turn to left to center with out doing anything to adversly
affect improvement.
Bill

> In effect when Arch lowered the back of the coach he increased the
> amount of caster. While the test was conducted in advance of
> completion of the alignment the same test can be conducted
> by anyone who believes their coach is properly aligned.
>
> Caster can be accidentally adjusted through bad ride height.
> Intentially adjusting ride height with the air to test changes
> in caster is valid.
>
> When I discussed caster with Jim Bounds he advised that more caster
> is good. Helps to keep the coach going straight.
 
Bill,
Glad to hear you got your grunting out of the way. My wheeel did the
samething when I did my steering box. I had the blue splines off a notch. I
simply dropped the pinch bolt out on the top (of the steering CV joint
spline) and pulled the blue splined joint apart and moved it over a notch.
Was right back to normal then. HTH. Also I'd advise flushing the system
again and add the filter like I mentioned on Gene's site, especially if the
old fluid was like motor oil coming out... (cheap insurance, guy).

Nate '75GB (splined... not threaded, thanks) Omaha

>

Date: Thu, 11 May 2000 07:57:25 -0700
From: bill e satterfield
Subject: Re: GMC: Testing caster

By the way, completed installation of new steering gearbox yesterday.
Have'nt
gave it real test with toad attached yet but did drive it a couple of
miles and must say steering is much improved. Now have to turn steering
wheel 1/2 turn to left to center with out doing anything to adversly
affect improvement.
Bill
 
Nate , Thanks for the tip. Saved lots of "grunting" Did it just like
you said and it worked the way it was supposed to. Steering is 100%
better. New steering gear accounted for most of that.
Bill

> Bill,
> Glad to hear you got your grunting out of the way. My wheeel did
> the
> samething when I did my steering box. I had the blue splines off a
> notch. I
> simply dropped the pinch bolt out on the top (of the steering CV
> joint
> spline) and pulled the blue splined joint apart and moved it over a
> notch.
> Was right back to normal then. HTH. Also I'd advise flushing the
> system
> again and add the filter like I mentioned on Gene's site, especially
> if the
> old fluid was like motor oil coming out... (cheap insurance, guy).
>
> Nate '75GB (splined... not threaded, thanks) Omaha
>
> >
>
> Date: Thu, 11 May 2000 07:57:25 -0700
> From: bill e satterfield
> Subject: Re: GMC: Testing caster
>
> By the way, completed installation of new steering gearbox
> yesterday.
> Have'nt
> gave it real test with toad attached yet but did drive it a couple
> of
> miles and must say steering is much improved. Now have to turn
> steering
> wheel 1/2 turn to left to center with out doing anything to
> adversly
> affect improvement.
> Bill
>