4106 GM right angle steering gear adjusting

Friday1 · February 03, 2021, 12:35:51 PM

In my 4106 manual it refers to the right angle steering box in the Driver Compartment as having an adjustment and a jam nut to lock it down. I can't get a clean picture with my remote camera. Has anyone ever adjusted that or had one apart? I'm thinking of dropping the front bumper and drilling a hole big enough to see in there and making a cover for the hole. It looks like the bumper will hide the hole. Thanks in advance.

richard5933 · February 03, 2021, 01:41:03 PM

Are you talking about the parts in the lower-left of the illustration in this page from the manual? If so, I've never heard of it needing to be adjusted.

You should have a hinged cover with a spring-loaded hold down you can open to gain access to the steering parts. Usually if there is wear it's in the universal joints or the slip joints.

As for adjustment, I've only heard of adjustments being made to the steering gear mounted by the front axle. If you do need extra access, perhaps you can pull the fog light on the driver's side instead of cutting another hole.

Nothing that needs maintenance should require a hole to be cut in the front of the bus for access.

chessie4905 · February 03, 2021, 05:07:38 PM

That angle box should use shims for adjusting gear lash. Check for play AT THE ANGLE BOX before attempting to remove. Normally, play is in the u-joints, slip joint, or steering box. I place two pipe wrenches in opposite directions on steering shaft and then have someone move steering wheel back and forth while observing joints, and slip joint. Btw, that driveshaft is same, I believe, as the front shaft on a military Jeep from the 50's. Brother was into Jeeps back when we had the 04. The steering shaft was pretty sloppy. He looked at it and hmm, that looks like one my Jeep. He had a nos shaft in basement. It fit perfectly. Go figure.🤔

Friday1 · February 03, 2021, 08:53:07 PM

Quote from: richard5933 on February 03, 2021, 01:41:03 PM
Are you talking about the parts in the lower-left of the illustration in this page from the manual? If so, I've never heard of it needing to be adjusted.

You should have a hinged cover with a spring-loaded hold down you can open to gain access to the steering parts. Usually if there is wear it's in the universal joints or the slip joints.

As for adjustment, I've only heard of adjustments being made to the steering gear mounted by the front axle. If you do need extra access, perhaps you can pull the fog light on the driver's side instead of cutting another hole.

Nothing that needs maintenance should require a hole to be cut in the front of the bus for access.

On the diagram, to the left of the #11 arrow is the front cover for the bevel gear. It looks like a jam nut and adjuster.
I have already adjusted the steering box. It wanders a little and all the usual suspects that are the cause-tie rod ends, king pins, tires, drag link etc are not loose. I have replaced the slip joint in the #14 shaft. I cleaned 10 LBS of grease from under the cover. The PO had a laminated lube order for the chassis but the shop he went to didn't follow it very well. The shop he went to missed a quarter of the grease fittings on this bus. I will let you know what I find on the bevel gear.

richard5933 · February 04, 2021, 03:55:18 AM

Quote from: Friday1 on February 03, 2021, 08:53:07 PM
On the diagram, to the left of the #11 arrow is the front cover for the bevel gear. It looks like a jam nut and adjuster.
I have already adjusted the steering box. It wanders a little and all the usual suspects that are the cause-tie rod ends, king pins, tires, drag link etc are not loose. I have replaced the slip joint in the #14 shaft. I cleaned 10 LBS of grease from under the cover. The PO had a laminated lube order for the chassis but the shop he went to didn't follow it very well. The shop he went to missed a quarter of the grease fittings on this bus. I will let you know what I find on the bevel gear.

I believe that the bevel gear box is filled with "steering gear lubricant SG" and not grease, filled through the breather. Like Chessie4905 mentioned, section 16 page 9 talks about using shims to adjust the bevel gear, and I can't find any mention of making the adjustment using an adjusting screw.

My guess is that if the slop is in the bevel gear, you might be best to fully inspect the bevel gear to check for worn bearings or other components, which would probably be best done out of the bus. But, before doing anything like that it might be a really good idea to call Luke and find out what replacement parts are available. Would really suck to get it opened up and not have parts to reassemble or fix the problem. Might also be a good idea to pick his brain for a minute to see if he's got other suggestions on where to look for slop before tearing this apart.

Jim Blackwood · February 04, 2021, 07:19:02 AM

Just be aware that when you adjust worn steering gears you can end up worse than you started if you don't pay attention. The gears wear in the straight ahead position which means if you tighten them up there so the play is gone they can bind up at the ends. You could end up not being able to straighten out from a turn and wouldn't that be fun?

Jim

chessie4905 · February 04, 2021, 07:22:38 AM

or if you rotate gears 180, you end up with play middle of turning. Box is not that difficult to remove btw.

RJ · February 04, 2021, 03:42:21 PM

Quote from: Friday1 on February 03, 2021, 12:35:51 PM
In my 4106 manual it refers to the right angle steering box in the Driver Compartment as having an adjustment and a jam nut to lock it down.

Friday -

Am curious as to what you've got for your steering components on your 4106.

Is it straight manual?

Is it power assist - with the hydraulic cylinder on the tie rod?

Is it full power steering with a Sheppard box on the axle?

It's possible that the issue you're concerned about may be related to the above.

FWIW & HTH. . .

PS: What's the VIN of your 4106? PD4106-XXXX? Fellow busnuts Jon Ulse and Bill Brachold have been compiling a "Survivor's List" for historical purposes of the GM Parlor Cars such as yours.

fortyniner · February 05, 2021, 04:59:08 PM

What about the caster angle? Perhaps its just not enough to center it.

The play in my 4106 was in the spline shafts. I swapped those out when installing power steering.

Friday1 · February 07, 2021, 08:50:11 PM

Quote from: fortyniner on February 05, 2021, 04:59:08 PM
What about the caster angle? Perhaps its just not enough to center it.

The play in my 4106 was in the spline shafts. I swapped those out when installing power steering.
Mine too. The PO was taking the bus to a shop where they didn't follow the lube order. My spline shaft was shot from no grease-EVER! I took the bus to a truck alignment shop last summer. The tech was not happy working on an old bus....until I pulled on the rack and he saw it was clean underneath and all the adjustments worked with no sweat. He said it was not off much on any adjustments. I have adjusted the play in the box on the axle. None of the usual suspects are loose in the steering system. I'll figure it out. It is up on jackstands for the winter so no test drives for a while.

chessie4905 · February 08, 2021, 04:54:14 AM

GM coaches with manual steering have non or negative caster as they age. Makes low or tolerable effort to steer. The downside is the wander and constant corrections to steering while driving. Changing the caster setting to 1 to 1 1/2 degree positive will eliminate the wander issue, unless you have a lot of play in the steering components. Down side is steering will require increased effort, not a big deal if you have power steering. To change this, you adjust the big torque rod with the threaded coupler above front axle. It's the only one with the threaded section. If it is very rusty, will need threads wire brushed thoroughly and repeated soaking with penetrant. Using a tapered flat chisel to spread split in collar will help free collar from threads helps to free it. Put chisel in crack, making sure not to contact threads at either end of crack and drive it into crack enough to spread slightly after thoroughly loosening both clamp bolts and turn collar with 3' pipe wrench. Use a level on underside of axle tube. You want to tilt the front of bottom uphill 1 or 2 degrees. Usually you find the opposite when checked. You can also get more accurate readings with an inclinometer. Probably available on Amazon. Mine is a Craftsman bought years ago.