Adjusting steering box

[Lin]

It's been two months since we moved.  I am just now getting back to the bus since we intend to go on a trip next week.  In the hope that my tight steering problem is in the adjustment rather than worn bearings in the steering column as was suggested to me, I would like to loosen it up at the box.  It is a Ross #TE 715993.  The only place that I saw that looked like it may be an adjustment was a large bolt (about 1 1/4 inches) with grooves in it on the inside face of the box.  Do I have it right?  Would turning it about a half turn counter clockwise be loosing it enough?  I also see that there is an oil drain plug and filler on it.  I was wondering if this is fed by the power assist system or does it have its own isolated oil supply.

[Sojourner]

Lin....The number you posted is not found in TRW/Ross listing. It may be casting number? ?

Here a link:
http://trucksteering.trwauto.com/servicemanuals/1,2503,3~55~30,00.html

If you can get a picture of the steering box and the first half of the steering link (connected to heavy arm (pitman) to steering knuckle) and post it.

You could have power assisted steering....a hydraulic slave cylinder as part of steering link.

Wait to hear from you.

FWIW

Sojourn for Christ, Jerry

[Lin]

Sojourner,
     It is power assist.  The bolt I had mentioned is for adjustment.  It had a large locknut around it.  I loosened it a bit and it seemed to add more play to the wheel.  I took it for a short ride.  It may actually have steered better, but there was a strong wind, so I am not sure.  We are going on a trip next week, so that should give it a test.  Thanks.

[Sojourner]

Thanks for update.

Now we know you have power assisted steering system, you have points to check & adjust.
1)   Push & pull adjuster to end of pitman shaft of large half round shape cover of the steering box.
2)   Adjust the end play of the drag link between pitman arm and wheel steering arm.
3)   Either one or both of the above adjustments can cause binding or more play than normal.
4)   You need a bus manual to properly correct the adjustment or replace worn parts.

About the power assisted steering.....steering play will be about 2.5 inches at the steering wheel which is normal. To get less play than that is to go for integral steering box. Why is it less? First of all you need to know that a hydraulic control valve is what applies oil pressure to either a boaster cylinder or a piston. The power assist system has slave cylinder after the steering box which is about 12 to 1 ratio. The integral power steering box does not a slave cylinder but instead a piston before the gear ratio. In other words, soon as you turn the steering wheel 1/8 of an inch it applied oil pressure to the integral's piston.
And the power assisted steering with slave is no longer in vehicles since early 80's.

FWIW

Sojourn for Christ, Jerry

[Lin]

Thanks for that info.  I will try to find someone that knows how to do it right before I mess with it much more.  I will check out my manual again, but I do not remember instructions on those adjustments.  The adjustment I made seems to have added free-play at the wheel, which only had about an inch before.

[gus]

Mine was too loose when I first got it. Play at the wheel was around 2-3" and it wore me out. This is the way I did it on my 4104 with factory original manual hyd boosted system;

The adjustment is a slotted pin inside a locknut (I think it takes an 11/16" box wrench) on the top left (Driver) side of the steering gear box. You have to jack up the front axle a bit (Don't forget to put a block at the axle bumper to keep the suspension from collapsing on you) to get to it.

Loosen the locknut while holding the pin with a thick slot head screwdriver to keep it from moving. (Mine is a slot head, sounds as if yours has a bolt head. No matter, the adjustment is the same.

Turn the pin CCW (CW as viewed from the bottom)1/8 turn. You've already done this.

Tighten the nut slightly.

Check the steering. It should increase the play at the rim about 1" or slightly less.

If there is much less than 1" play remaining turn the pin again only about 1/8th of a turn.

Once you get it to about 1" of play at the steering wheel rim turn the wheels from full L to full R to make sure there is no binding. You don't want more than 1" play, otherwise it will kill you on long trips and in high crosswinds. Mine is slightly less than 1" with no binding at full lock.

Since the most wear is at the center of the worm gear it can bind at the full L/R positions because the gear does not wear as much there. This causes binding when the adjustment at the center is too tight.

The steering box has nothing to do with the hyd boost. Those cylinders are at the steering linkage. This system is manual in straight driving, it is only boosted when moving the wheel.

[Lin]

Gus,
Thanks for the info.  I did figure out how to adjust it but did not know how much, so I turned it a full half turn.  The play increased from less than 1" to about 3".  This was too much of a good thing, so I moved it back about 1/4 turn.  I'd say there is about 2" of play now.  We are taking a trip next week and I thought to test it at that setting, but maybe, if it's supposed to be tighter, I'll try to get it closer to 1".  It is real easy to get to.  You just stick your head in the empty spare tire compartment, face right, and there it is.  The bonus for doing this is discovering that my spare tire has a 12" sidewall gash.  The bus gods are nothing, if not full of surprises!  I suspect I know what you mean about control issues from the gear being to loose, but the control issues, which I hope are merely because the gear was too tight, were at least equally annoying.  The steering would bind and not center itself going down the road which made driving a constant search for the right spot.  I never realized before how much I take that for granted.  If this does not work, I will have to look elsewhere for the solution.  Thanks again.

[gus]

Lin,

2" is probably too much if your trip is very long. My first trip was from AR to Carson City, NV and it was a real pain. Even with less than 1" it is still a lot of work steering for days at a time. My theory is to get as much play out as possible and still have no binding.

This steering system is not great at centering.

The MM actually says to disconnect the steering arm when adjusting to check for binding but I chose not to do that. If you have no MM you surely need one.

My spare tire compartment has a rear bulkhead so I have no choice except from underneath.

Part of my problem was lack of lubrication in the box. I solved my gear box oil leaking by using grease instead of oil. It made the steering much easier also. Now I grease it before each trip because there is no way to know how much grease is in the box. I'm sure it isn't fulll because is so big big it would take a lot of grease to fill it. Mine has a zerk fitting on the bottom of the box which I think was originally used for gear oil.