Centering the steering box

boybach

boybach

Well-known member
Dec 9, 2020
1,033
195
63
I've read through many threads in the archive on this subject as well as downloading instructions as to how to accomplish the task ..however, I still
don't understand WHAT I'm supposed to be doing as well as WHAT I'm lining up to be centered and WHERE I look to find what it is I'm supposed to be
looking at :cry: :roll:

Could someone please explain to me the process, keeping in mind I have no idea what the steering box actually does never having seen one before this
month - I've only ever dealt with hydraulic steering racks on my other vehicles and never had to muck about with them.

Help!

Larry
--
Larry - Victoria BC -

1977 Palm Beach VIN TZE167V101295 - 39,000 miles, PO said everything working but forgot the word NOT. New wiper blades, New SS exhaust system ..
 
In short, someone has messed with the tie rod adjusters over time. The box is then not pointing straight (exactly center) when going straight ahead.
(This also puts the entire steering linkage off center creating other issues). The box on center is when the flat on the input shaft is parallel to
the machined flat gasket surface where the cover is bolted on (and you are equal turns away from left or right). Once toe is reset to get box on
center you can then check that the steering wheel matches scribes on the upper shaft. Finally you correct the miss assembled intermediate shaft
permutations so that the shaft drops in top and bottom to the center of their keys.
--
John Lebetski
Woodstock, IL
77 Eleganza II
 
Larry,

Go read what I wrote to MikeB, in the thread "Steering Slop" 15 April. I would write it again, but the thread is still easy to find.

If you have questions, come on back here....

This is a very common issue with TZEs because man alignment shops are unaware of the special steering engine and so, when they need to set the tow,
they adjust one side only and then pull the steering wheel and put it back on a straight ahead. Ever after the coach is a bitch to keep in the lane.

Matt
--
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
 
OK!
I'm afraid my steering component vocabulary is rather limited ATM; no doubt I will become familiar with the terms as time goes on, but for now I have
no clear picture in my mind of where, what and how.

What I do have, is my coach with the grille removed, the blue shaft marked and removed ready for boot refit. So I'm looking down at the steering box,
the wheels are straight ahead and the steering wheel is locked and appears straight. What do I look at and do I look from above or below, at the left
or right side? All I want to do at this time is see if it's centered.

Thanks

Larry
--
Larry - Victoria BC -

1977 Palm Beach VIN TZE167V101295 - 39,000 miles, PO said everything working but forgot the word NOT. New wiper blades, New SS exhaust system ..
 
Thanks Bill, that's what I needed. I can see what everyone is talking about now :)

Larry
--
Larry - Victoria BC -

1977 Palm Beach VIN TZE167V101295 - 39,000 miles, PO said everything working but forgot the word NOT. New wiper blades, New SS exhaust system ..
 
I don't know where the photos are, but someone, 'way back, showed clamping
a steel bar to the flat on the input shaft to make it easier to visually
align to the assembly flat, as shown in Rob's photo.
Ken H.

On Mon, Apr 19, 2021 at 2:57 PM Bill Van Vlack
wrote:

> Here's some photos thanks to Rob Mueller.....
>
>
> http://www.gmcmhphotos.com/photos/aa-miscellaneous-photos/p56547-steering-box-input-shaft-alignment.html
>
>
> --
> Bill Van Vlack
> '76 Royale; Guemes Island, Washington; Twin bed, full (DS) side bath,
> Brazilian Redwood counter and settee tops,455, 6KW generator; new owner a/o
> mid
> November 2015.
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>
 
Now if some one had told me in the beginning that I had to remove the U-joint to see the flat, I'd be way ahead. :)

Larry
--
Larry - Victoria BC -

1977 Palm Beach VIN TZE167V101295 - 39,000 miles, PO said everything working but forgot the word NOT. New wiper blades, New SS exhaust system ..
 
Most alignment shops start out by turning the steering wheel to achieve the
correct toe in/out. Then, they adjust the tie rod ends on the other side of
the of the vehicle to correct the toe in/out. This results in moving the
center of the steering box. They then remove the steering wheel and point
it straight ahead. This works, sort of, on rear wheel drive vehicles, but
not on a GMC with front wheel drive. Makes them wander. To really do it
right, an adjustable drag link is very helpful. More complex than space
here permits for explanation in detail. Go on Jerry Work's web site, "The
dovetail joint", he has a very detailed alignment procedure there.
Jim Hupy
Salem, Oregon

> > Thanks Bill, that's what I needed. I can see what everyone is talking
> about now :)
> >
> > Larry
>
> The best set of pics is the ones that Bill VV pointed out. Pics by Alex F.
>
> http://www.gmcmhphotos.com/photos/steering-box/p54238-steering-box-adjustment.html
>
> Use the right arrow on pics to advance.
> --
> Larry
> 78 Royale w/500 Caddy
> Menomonie, WI.
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>
 
> Most alignment shops start out by turning the steering wheel to achieve the
> correct toe in/out. Then, they adjust the tie rod ends on the other side of
> the of the vehicle to correct the toe in/out. This results in moving the
> center of the steering box. They then remove the steering wheel and point
> it straight ahead. This works, sort of, on rear wheel drive vehicles, but
> not on a GMC with front wheel drive. Makes them wander. To really do it
> right, an adjustable drag link is very helpful. More complex than space
> here permits for explanation in detail. Go on Jerry Work's web site, "The
> dovetail joint", he has a very detailed alignment procedure there.
> Jim Hupy
> Salem, Oregon

Thanks for that, James. Jerry Work's method looks good and his explanation of caster and camber etc is pretty great.

Larry
--
Larry - Victoria BC -

1977 Palm Beach VIN TZE167V101295 - 39,000 miles, PO said everything working but forgot the word NOT. New wiper blades, New SS exhaust system ..
 
> Now if some one had told me in the beginning that I had to remove the U-joint to see the flat, I'd be way ahead. :)
>
> Larry

Larry,

An interesting point, but on my coach I don't have to. It is visible above (or maybe below) the carden joint casting.

Matt

--
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
 
The adjustable drag link adds complexity in that it’s another place to be wrong. It is for very fine nuisance adjustment correction only. Adding
and misusing adjustable drag link you can then have box on on center, wheel at 12 and have the steering linkage off to one side, meaning relay and
idler not straight. You will be able to turn further one way than other and amount of turn in toe will be asymmetrical.
--
John Lebetski
Woodstock, IL
77 Eleganza II
 
Ok, well I had a good look at the Mueller steering inspection guide and from his description/picture of the spline bolt position on the U-joint I
believe my steering box could be 60 or so degrees off center. I intend to correct this if I can.

As I understand it, the pitman arm and the drag link have to be separated so I can center the box - I'm guessing I need a pickle fork to do that?

Larry

--
Larry - Victoria BC -

1977 Palm Beach VIN TZE167V101295 - 39,000 miles, PO said everything working but forgot the word NOT. New wiper blades, New SS exhaust system ..
 
The pitman arm has a keyway so it only goes on one way. If you don't have an adjustable drag-link, then you need to adjust the tie rod end couplers on
each side to bring the steering box on center.
--
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
 
> The pitman arm has a keyway so it only goes on one way. If you don't have an adjustable drag-link, then you need to adjust the tie rod end
> couplers on each side to bring the steering box on center.

I do have an adjustable drag-link, but could anybody please confirm my plan to center the steering box?

I have the lower steering shaft marked, greased, re-booted and disconnected but the blue shaft sleeve U-joint is still attached to the input spline on
the steering box. I am about to remove the sleeve to expose the steering box input spline.

The way I understand it, I need to center the spline as per Mr. Mueller's guide, using a 3/4" 12 point socket, and in order to turn the spline to
center, the pitman arm has to be disconnected from the drag-link. How do I disconnect it? I can see it has a castellated nut and split-pin - do I need
to use a ball joint separator (pickle fork) to do that or will it simply release?

After the adjustment, is it straightforward to re-connect the pitman arm? I imagine it will be in a very different position than when it was released
- are you suggesting I change the length of the drag-link to accommodate the new setting? That does make sense, but JohnL455 said it would be a no-no
to make a large change, so I'm guessing the better plan is to adjust both tie rods the same amount to move the drag link into the new position?

Taking a day off today to get the plan thoroughly worked out before I dive into the job.

All input, gotchas, and advice sincerely appreciated - I've owned the coach exactly one month TODAY!

Thanks in advance

Larry

--
Larry - Victoria BC -

1977 Palm Beach VIN TZE167V101295 - 39,000 miles, PO said everything working but forgot the word NOT. New wiper blades, New SS exhaust system ..
 
Here is Ken Henderson's verbal write-up.. and note at the end he says the pitman arm does not need to come off... it only goes on one way!

http://www.gmcmhphotos.com/photos/data/6588/steering.pdf

Having done mine and checked it several times, this is how I would doing it again from scratch.

If your coach drives straight and no funny wear on the tires, then you can assume you have the front wheels aligned right, or close anyway. Take your
coach out for a quick test drive and determine the steering wheel position when the coach is going straight down the road. When you come back home,
drive the last 10 feet with the steering wheel in the position you had noted on your test drive. You now have your front wheels pointing straight
ahead (just maybe not the steering wheel!)

Open the engine cover and look down at the position of the relay arm and idler arm. They should be pointing straight back, parallel with the main
ladder frame. If not, then the link between the tie-rods out to wheels is off of its center point of movement. Use the tie-rod adjustment sleeves to
get the relay arm and idler arm in the center of their swing (straight back, parallel with the chassis frame). Turn the sleeves a little bit on each
side, alternating side to side and in the opposite direction so you do not move the front wheel position. You only want to shift the connecting rod to
the center of its movement by setting the relay arm and idler arm point straight back.

Now you have your wheels pointing straight ahead and the relay arm in the center of its movement swing.

Next you need to get your steering box at the high point. Pull the intermediate shaft universal joint off the input shaft to the steering box. Use
your adjustable drag-link to line up the flat on the input shaft to be parallel to the cover plate on steering box as shown in Alex's photos here:
Turning the drag-line adjustment will make the steering box input shaft move.

http://www.gmcmhphotos.com/photos/steering-box/p54239-photo-2.html

At this point you have your wheels straight ahead and your steering box set on high-point. Now you need to get your steering wheel set so it is at 12
o'clock. You need to align the u joint to the input shaft next. Read Ken's instructions from his PDF above (I think the drill is actually 15/32") If
you are lucky your steering wheel will be at 12 o'clock. Otherwise you will need to follow Alex's and Ken's instructions to reclock the intermediate
steering shaft assembly. The steering wheel should be at 12 o'clock position when the steering box is at high-point. Your should not need to change
these adjustments from the steering wheel to the steering box again.

When you have done all that, take it for a test run. If you find the steering wheel is a bit off 12 o'clock when going straight, you can use the drag
link to fine adjust it so the box is at high point when you are driving down the road.

Photos and more instructions here:

http://www.gmcmhphotos.com/photos/g6588-steering-box.html

--
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
 
Nice info Bruce.

Sully
Bellevue wa.

> Here is Ken Henderson's verbal write-up.. and note at the end he says the
> pitman arm does not need to come off... it only goes on one way!
>
> http://www.gmcmhphotos.com/photos/data/6588/steering.pdf
>
> Having done mine and checked it several times, this is how I would doing
> it again from scratch.
>
> If your coach drives straight and no funny wear on the tires, then you can
> assume you have the front wheels aligned right, or close anyway. Take your
> coach out for a quick test drive and determine the steering wheel position
> when the coach is going straight down the road. When you come back home,
> drive the last 10 feet with the steering wheel in the position you had
> noted on your test drive. You now have your front wheels pointing straight
> ahead (just maybe not the steering wheel!)
>
> Open the engine cover and look down at the position of the relay arm and
> idler arm. They should be pointing straight back, parallel with the main
> ladder frame. If not, then the link between the tie-rods out to wheels is
> off of its center point of movement. Use the tie-rod adjustment sleeves to
> get the relay arm and idler arm in the center of their swing (straight
> back, parallel with the chassis frame). Turn the sleeves a little bit on
> each
> side, alternating side to side and in the opposite direction so you do not
> move the front wheel position. You only want to shift the connecting rod to
> the center of its movement by setting the relay arm and idler arm point
> straight back.
>
> Now you have your wheels pointing straight ahead and the relay arm in the
> center of its movement swing.
>
> Next you need to get your steering box at the high point. Pull the
> intermediate shaft universal joint off the input shaft to the steering box.
> Use
> your adjustable drag-link to line up the flat on the input shaft to be
> parallel to the cover plate on steering box as shown in Alex's photos here:
> Turning the drag-line adjustment will make the steering box input shaft
> move.
>
> http://www.gmcmhphotos.com/photos/steering-box/p54239-photo-2.html
>
> At this point you have your wheels straight ahead and your steering box
> set on high-point. Now you need to get your steering wheel set so it is at
> 12
> o'clock. You need to align the u joint to the input shaft next. Read
> Ken's instructions from his PDF above (I think the drill is actually
> 15/32") If
> you are lucky your steering wheel will be at 12 o'clock. Otherwise you
> will need to follow Alex's and Ken's instructions to reclock the
> intermediate
> steering shaft assembly. The steering wheel should be at 12 o'clock
> position when the steering box is at high-point. Your should not need to
> change
> these adjustments from the steering wheel to the steering box again.
>
> When you have done all that, take it for a test run. If you find the
> steering wheel is a bit off 12 o'clock when going straight, you can use the
> drag
> link to fine adjust it so the box is at high point when you are driving
> down the road.
>
> Photos and more instructions here:
>
> http://www.gmcmhphotos.com/photos/g6588-steering-box.html
>
>
> --
> Bruce Hislop
> ON Canada
> 77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
> My Staff says I never listen to them, or something like that
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>
 
Thanks Bruce, will digest your post in full later on! Much appreciated

Thanks

Larry
--
Larry - Victoria BC -

1977 Palm Beach VIN TZE167V101295 - 39,000 miles, PO said everything working but forgot the word NOT. New wiper blades, New SS exhaust system ..
 
Great write-up, Bruce..

A suggestion... I found that my steering wheel marks were not lined up; they were one spline off. I'd suggest that after the first ride, remove the
steering wheel, check the marks, and re-install with them lined up.
--
Bill Van Vlack
'76 Royale; Guemes Island, Washington; Twin bed, full (DS) side bath, Brazilian Redwood counter and settee tops,455, 6KW generator; new owner a/o mid
November 2015.
 
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