I hope someone on the list can give me some information / advice on a
steering problem my 77 Transmode has bugged me with for the last few
thousand miles. This will take some time to explain and I hope you'll
bear with me to the end.
I have never been happy with "looseness" in the steering on my coach
which now has 88,000 miles . Over the last 10,000 miles in 3 year's
time I've replaced a number of the orginal stock parts to "tighten up"
and remove annoying clunks and other noise from the steering and front
end area. Those parts include: lower ball joints (uppers are fine),
front shocks ( w/Bilsteins) , steering dampener shock absober, knuckles
and front wheel bearings, lower steering column bearing, steering
coupling shaft with CV joint, two (that's right TWO!) relay levers.
The ball joints at the tie rods, idler arm, drag link and pitman arm all
appear to have no or very little play. There is slight play in the
steering gear box when I hold the disconnedted drag link still and move
the steering wheel back and forth slightly. But, I don't know what's
normal for the steering gearbox. Any advice on what's "normal" will help
me decide if I should repalace it .
This brings me back to the relay lever. The orgingal part was shot with
lots play in all planes of motion when it was replaced at 80,000 miles.
I had installed one of the rebuilt units which comes with 3 new
bushings and new intermediate rod to relay lever ball joint. There was
a very noticeable improvement in streering tracking and wander control
with this repair. However, eventhough the lever was torqued to specs
(250 to 300 ft.-lbs.) and was kept well greased, the bushings wore out
within 3000 miles and the lever knocked with each road bump. My
mechanic guessed it was a defective rebuild (bad metallurgy?)and
replaced it with another rebuilt unit. That fixed the problem again but
now with about 2500 miles on this lastest lever the same wear and play
has developed again. (Honest, guys, I don't use my GMC as an off the
road dune buggy --just everyday Interstate driving.)
Anyway, what I've noticed is that when I disconnected the ball joints
from both ends of the relay lever with it still bolted in to the cross
member at 250 ft.-lbs.+ torque, and while grabbing the lever by hand at
both ends, I can rock it back and forth in the verticle plane. (This
movement is not the same as the slight few thousandths of an inch
movement up and down along the bushings axis which I think should be
expected as the rubber seals at the top and bottom of the lever bushings
compress.) This rocking motion translates to play in the steering
linkage with random side to side movement of the front wheels. This
movement is very noticeable at the steering wheel and is not accectable.
When I removed the relay lever from the coach, I could feel a noticeable
clearance between the innner steel bushing and outer brass bushings
pressed into the lever. The X-7525 manual doesn't state what the
clearance should be, but it appears excessive to me.
So, I would appreciate very much hearing from any one who knows how much
movement in the relay lever bushings I should expect with a new unit
made to the factory specs. I very much would like to know what those
specs. are before I buy another "rebuilt" lever. Not only is this
frustrating, its getting expensive too.
Thanks everyone for listening.
Phil Stewart
steering problem my 77 Transmode has bugged me with for the last few
thousand miles. This will take some time to explain and I hope you'll
bear with me to the end.
I have never been happy with "looseness" in the steering on my coach
which now has 88,000 miles . Over the last 10,000 miles in 3 year's
time I've replaced a number of the orginal stock parts to "tighten up"
and remove annoying clunks and other noise from the steering and front
end area. Those parts include: lower ball joints (uppers are fine),
front shocks ( w/Bilsteins) , steering dampener shock absober, knuckles
and front wheel bearings, lower steering column bearing, steering
coupling shaft with CV joint, two (that's right TWO!) relay levers.
The ball joints at the tie rods, idler arm, drag link and pitman arm all
appear to have no or very little play. There is slight play in the
steering gear box when I hold the disconnedted drag link still and move
the steering wheel back and forth slightly. But, I don't know what's
normal for the steering gearbox. Any advice on what's "normal" will help
me decide if I should repalace it .
This brings me back to the relay lever. The orgingal part was shot with
lots play in all planes of motion when it was replaced at 80,000 miles.
I had installed one of the rebuilt units which comes with 3 new
bushings and new intermediate rod to relay lever ball joint. There was
a very noticeable improvement in streering tracking and wander control
with this repair. However, eventhough the lever was torqued to specs
(250 to 300 ft.-lbs.) and was kept well greased, the bushings wore out
within 3000 miles and the lever knocked with each road bump. My
mechanic guessed it was a defective rebuild (bad metallurgy?)and
replaced it with another rebuilt unit. That fixed the problem again but
now with about 2500 miles on this lastest lever the same wear and play
has developed again. (Honest, guys, I don't use my GMC as an off the
road dune buggy --just everyday Interstate driving.)
Anyway, what I've noticed is that when I disconnected the ball joints
from both ends of the relay lever with it still bolted in to the cross
member at 250 ft.-lbs.+ torque, and while grabbing the lever by hand at
both ends, I can rock it back and forth in the verticle plane. (This
movement is not the same as the slight few thousandths of an inch
movement up and down along the bushings axis which I think should be
expected as the rubber seals at the top and bottom of the lever bushings
compress.) This rocking motion translates to play in the steering
linkage with random side to side movement of the front wheels. This
movement is very noticeable at the steering wheel and is not accectable.
When I removed the relay lever from the coach, I could feel a noticeable
clearance between the innner steel bushing and outer brass bushings
pressed into the lever. The X-7525 manual doesn't state what the
clearance should be, but it appears excessive to me.
So, I would appreciate very much hearing from any one who knows how much
movement in the relay lever bushings I should expect with a new unit
made to the factory specs. I very much would like to know what those
specs. are before I buy another "rebuilt" lever. Not only is this
frustrating, its getting expensive too.
Thanks everyone for listening.
Phil Stewart
