Community Forums

Lacota · 11-26-2020, 10:33 PM

Hi all,
I can't get my steering right. Wants to wander. Two line-up's and all is good. New tires etc. I installed a new steering shock.
The only thing I haven't tried is the power steering fluid filterI plan on this soon.
Now, has anyone experienced a power steering pump going out? This is a Gillig chassis and I know they are the best based on other units I have owned.
Kinda at my wits end. Any help will be much appreciated.
Best to all, Don

429CV23 · 11-27-2020, 06:44 AM

How much slop is in the steering box?

wolfe10 · 11-27-2020, 07:23 AM

Wander unlikely to be related to power steering fluid. Issues there would more likely result in more steering effort. That does not mean that the filter(s) should not be serviced-- consider this part of routine maintenance.

Wander is generally related to one of these factors (or combinations of them):

Insufficient CASTER on front axle
Insufficient TOE-IN

Over-inflated front tires
Play in steering box or linkages.

So, if you would:

Post what the front alignment specs for your alignments show CASTER and TOE-IN

Are your tires inflated to your tire manufacturer's recommendation (inflation table) for your actual weight?

Have you visually inspected steering for play-- very easy with two people. With engine OFF, have a helper turn the steering wheel left-right-left-right just through the play in the wheel. You look starting at the upper steering column U joint all the way to the right front wheel for play in any component. Depending on steering box, some have play externally adjusted-- many do not. To remove play from a Sheppard steering box, for example, they have to be rebuild and "blue-printed" (the fitting of bearings to achieve much finer tolerances/less play). There is a company in Washington state that specialized in blueprinting these boxes.

Harvard · 11-27-2020, 03:40 PM

POPULAR MECHANICS MAY 1973:
START QUOTE:
If too little caster exists, the car will wander and weave,
thus necessitating constant corrections in steering.
END QUOTE:

Too little caster creates a dead "do nothing" zone between left and right. The driver has the impression the steering box needs to be tightened up. Caster is adjusted on solid axels with wedges installed between the axel and the spring.

Lacota · 11-27-2020, 08:40 PM

Thanks for the reply's. Air pressure is good. As I remember 95 in front and 105 in rear.
Alignment shop did not want to increase toe-in more yet.3,000 mile trip did not show any wear on front tires.
When I greased King pins Right side took grease. Driver side did not take grease good. That wheel when disconnected from drag link was extremely hard
to turn by hand. I heated and greased again. Not as good as left side but better.
Steer shock helped about 50%. My 36' Gillig drove like a Town Car. This 40' you have to be alert 120% and cannot relax...white knuckle.
I cannot see any looseness in the steering.
I have never replaced a steering pump due to wear. Just wondered if that might be an issue before I go to line up shop again.
Thanks for the input...any more ideas?
Best to all, Don

deandec · 11-28-2020, 07:16 AM

Your air pressures are the reverse of our rig.

Could this cause stiff steering?

David 70 · 11-28-2020, 07:33 AM

King pins MUST be loose . If not they will bind and not let the steering return to neutral by them selves. Instead you are trying to center the steering and over correcting. Have your alignment shop replace and hone the bushings. I don't understand that the shop did not catch that. I think I would be looking for a different shop.

Harvard · 11-28-2020, 09:32 AM

When it comes to interpreting the caster specification, think outside the box. For example, given 3.0 +/-0.75, shoot for 3.75 which is better then 3.0.

Lacota · 11-28-2020, 11:45 AM

Quote:

Originally Posted by David 70

King pins MUST be loose . If not they will bind and not let the steering return to neutral by them selves. Instead you are trying to center the steering and over correcting. Have your alignment shop replace and hone the bushings. I don't understand that the shop did not catch that. I think I would be looking for a different shop.

David,
Ah ha! I have been waiting for your answer. When I dropped the drag link it took about 100lbs to turn Dr. side wheel. To grease the king pin it would blow the top seal. I heated housing trying to get the pin to accept grease and reseated end caps. It took some grease but blew seal again.
The coach has been sitting for years and grease has turned to wax. Shop did not know king pin was stuck. I called him and he said steering should overcome stiff king pin. I kinda wondered on that statement.
I have thought all along that this is my problem. The wheel after grease is about 25% better but still stiff. I haven't driven it since greasing the pin.
Should I have them hone and re-grease?
This coach sat for years in the AZ heat. I do plan on changing the ATF in the steering system and filter. I heard the engine radiator fan make a sound like cavitation when I first left but it went away right away and didn't make any more sounds in 3K miles.
This coach is really low miles but sitting is its own worst enemy. Thanks for the reply's and any more input would help. It has been sitting for a year now since last trip so I too am to blame..Best, Don

Lacota · 11-28-2020, 11:51 AM

One more item. It drives and steers great up to 40 to 45 MPH. cruise speed is only 60 MPH. One gear higher would be great but steering gets worse the faster it goes. Just thought I'd add this, Don

Harvard · 11-28-2020, 02:19 PM

Here is a link to a recent experience with a caster change to a solid front axel

https://www.irv2.com/forums/f22/more...ml#post5537005

FWIW, the caster effect increases with speed.

Lacota · 11-28-2020, 08:33 PM

Quote:

Originally Posted by Harvard

Here is a link to a recent experience with a caster change to a solid front axel

https://www.irv2.com/forums/f22/more...ml#post5537005

FWIW, the caster effect increases with speed.

Wow, this gives me something to work to. I need to find the invoice and specs. on the last alignment and will post tomorrow. I think there is adjustment turn buckles built in for camber.
If I can find the Specs. on the alignment will you be able to see what adjustments are needed?
As speed is increased it gets worse. Is that what I am reading?
Thanks a bunch for all the help...Don

Harvard · 11-28-2020, 09:40 PM

Quote:

Originally Posted by Lacota

....As speed is increased it gets worse. Is that what I am reading?
....

No. For a given amount of caster, the faster you go the more the caster effect. (The faster you go the more the vehicle wants to go in a straight line.) If you have too little caster to begin with then it may be there is less for the speed effect to be dominant. Three degrees does not make for good handling at highway speeds no matter what the vehicle.

Here is another solid axel link you may find useful.

https://www.ford-trucks.com/forums/1...of-caster.html

Yes, do post the caster setting from your alignment report.

Harvard · 11-29-2020, 01:29 PM

Quote:

Originally Posted by Lacota

....
As speed is increased it gets worse. Is that what I am reading?
....

To put it in different words:

Almost every "too little caster" handling post starts out with wandering and an uncomfortable feeling at highway speeds.

Once the caster has been increased the wandering clears up and the feeling that the new found stability at highway speeds feels even more stable with increasing speed.