too easy steering, no road feel

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idahored

idahored

Member
Joined
Mar 15, 2017
Posts
21
Location
Mountan Home, Idaho
When I first bought my 1995 Itasca Passge 23RC,, I had an alignment done because it seemed to wander allot. It didn't seem to help any :( To me the steering is way too easy, hardly any feel of the road, which I feel, contributes to the coach having a tendancy to wander quite a bit.  Maybe the alignment tech missed the settings ? Other ideas ?
Idahored
Mtn Home, Id
 
Sounds like the tires are overinflated. Are you using the figure on the tire? If so that is way too much air. You need to figure out how much air to put in the tires by getting your RV weighted and then go to the tire manufacturers website to see how much air you should have in the tires.
 
Harvard said:
Too little +caster will manifest itself as "wandering" and "loose steering" at highway speeds.

http://www.rvforum.net/SMF_forum/index.php?topic=40337.0
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Possibly so, but as Tom indicates, excessive tire pressure can do that -- personal experience speaking. If, after weighing the coach (at least each axle's weight), and setting pressure to the tire manufacturer's recommendation for that weight, you still have the problem, then caster might be something to check.
 
Larry N. said:
Possibly so, but as Tom indicates, excessive tire pressure can do that -- personal experience speaking. If, after weighing the coach (at least each axle's weight), and setting pressure to the tire manufacturer's recommendation for that weight, you still have the problem, then caster might be something to check.
Click to expand...

Reducing tire pressure increases the caster trail which has an effect the same as increasing caster. Since reducing tire pressure makes a noticeable difference in the caster trail then one might imagine the effect of adding 2 degrees of caster on top of reducing the pressure.
 
The steering box has a nut with a screw in the middle. This is used to tighten up the steering. It changes the pressure on the worm gear. Any garage can adjust that in 5 minutes. Any garage! Also, anyone doing an alignment should have adjusted your camber to steer to the left. Like a semi truck you spend the majority of your time in the right lane like a truck so they adjust your camber so the crest of the road does not keep pulling you to the right.
 
Well, that '95 coach would not have had tight responsive steering even when new, so it's hard to judge. It's just a mid-90's Chevy P-series medium truck chassis adapted for a motorhome and heavily loaded as well. The P-series chassis has an independent front suspension with air bag assist, so make sure the bags have air and are adjusted for a good balance of comfort and handling. You can find Chevy P30/p32 Motorhome chassis manuals of that vintage online.

Wandering was an endemic problem in those years (and beyond). See the Motorhome Handling Primer in the RVForun Library for some causes and possible fixes. http://www.rvforum.net/miscfiles/MH_Steering_Handling_%20Primer.pdf 

Another excellent source of info can be found at http://www.supersteerparts.com/faq/helpful-articles/

Excessive tire pressure is probably the #1 suspect, especially these days when tire and front end shops typically over-inflate to avoid any possibility of a lawsuit akin the the Ford Explorer rollover debacle.

Next comes the terribly sloppy Chevy steering bell crank. It was notorious for slop and the standard fix is to install the far superior Supersteer Bell Crank. http://www.supersteerparts.com/products/supersteer-bell-crank-for-p303237-chassis.html

You can get a copy of the originalPassage brochure at https://winnebagoind.com/resources/brochure/1995/95-Passage-bro.pdf
 
Here are a couple of things that maybe I should post. The tires are Firestone LT235-85R16 Transforce HT models. The side wall says 80# cold. The tires have about 3K miles on them, all installed at the same time. I took it to a commercial tire center and they recommended the front tires should be at 80# and the rear duels at 75#. Where and why they came up with those figures, they didn't say. My coach manual says the tires should be at 65#, but I haven't a clue as to what brand it originally came with. The coach has 74K miles. I explained my steering problem, and they said if it still wandered then maybe dropping the front tires down about 10# to see if that helped. I'm running about 50# of air in the front coil spring bladders. I culdn't find any air pressure recommendation for those. I think I will try dropping the front air pressure to see if it helps at all. Thanks a bunch for all the replies and recommendations !
 
idahored said:
I'm running about 50# of air in the front coil spring bladders. I couldn't find any air pressure recommendation for those. I think I will try dropping the front air pressure to see if it helps at all.
Click to expand...

Here's a link to the Chevrolet P-30 Chassis Manual:

http://www.gmcmi.com/wp-content/uploads/2014/05/P30-Chassis-Manual.pdf

Page 3-9 says:

"Inflation pressures should be maintained at 10 PSI minimum to avoid chafing . Under load, 40-50 PSI is recommended for a 4,300-Ib . suspension, 50 PSI for a 5,000-lb . suspension. 70 PSI is required on the 5,300-Ib suspension . 80-90 PSI is recommended for the F44 5,500-Ib . optional 16,000-Ib . suspension."
 
The tires are Firestone LT235-85R16 Transforce HT models. The side wall says 80# cold. The tires have about 3K miles on them, all installed at the same time. I took it to a commercial tire center and they recommended the front tires should be at 80# and the rear duels at 75#. Where and why they came up with those figures, they didn't say. My coach manual says the tires should be at 65#, but I haven't a clue as to what brand it originally came with.
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Tire brand makes little difference, but tire size does. Were  the originals also 235/85R16? If so, the RVmakers psi recommendation is probably sound. Firestone says that the LT 235/85R16 can carry 2623 lbs (single) and 2381 (dual). I seriously doubt if you need more than 65 psi on the front axle of that coach cause that's enough for a 5000 lb axle. 80 psi would handle a 6000 lb axle. See the Firestone inflation tables at the link below.

https://commercial.firestone.com/content/dam/bcs-sites/bridgestone-ex/products/TechnicalInformation/TBR/Fstn_LoadAndInflationTables_07-28-2016.pdf

40-50 psi in the air bags sounds about right, but you might play with it a bit because it does alter the firmness of the ride and handling.
 
SkateBoard said:
The steering box has a nut with a screw in the middle. This is used to tighten up the steering. It changes the pressure on the worm gear. Any garage can adjust that in 5 minutes. Any garage!
Click to expand...

DO NOT adjust the sector shaft adjuster, you will be asking for trouble. That is ONLY to be set with the box on a bench with nothing connected to it and with an inch pound torque wrench to spin the input shaft and set the pre-load on the sector shaft via the adjuster screw, and only after knowing how many inch pounds or turning resistance it should have.

Do the old school method of just turning the screw to eliminate play will result in a damaged box 9 out 0f 10 times.
That method worked for non-power assist boxes back in the 6o's but does not apply here.
 
dktool said:
DO NOT adjust the sector shaft adjuster, you will be asking for trouble. That is ONLY to be set with the box on a bench with nothing connected to it and with an inch pound torque wrench to spin the input shaft and set the pre-load on the sector shaft via the adjuster screw, and only after knowing how many inch pounds or turning resistance it should have.

Do the old school method of just turning the screw to eliminate play will result in a damaged box 9 out 0f 10 times.
That method worked for non-power assist boxes back in the 6o's but does not apply here.
Click to expand...

Funny, it's done all the time. I have first hand experience with it also.
 
I have to believe that there is a sheet attached somewhere in the motorhome that tells what the tire pressures are at max load.
That also should state the tire size that came with the coach and the max each axle can carry (weigh).
 
Gary RV_Wizard said:
Tire brand makes little difference, but tire size does. Were  the originals also 235/85R16? If so, the RVmakers psi recommendation is probably sound. Firestone says that the LT 235/85R16 can carry 2623 lbs (single) and 2381 (dual). I seriously doubt if you need more than 65 psi on the front axle of that coach cause that's enough for a 5000 lb axle. 80 psi would handle a 6000 lb axle. See the Firestone inflation tables at the link below.

https://commercial.firestone.com/content/dam/bcs-sites/bridgestone-ex/products/TechnicalInformation/TBR/Fstn_LoadAndInflationTables_07-28-2016.pdf

40-50 psi in the air bags sounds about right, but you might play with it a bit because it does alter the firmness of the ride and handling.
Click to expand...

Well Gary, from my coach manual, I find that the original tires were Michelin 7.50R16 truck tires and cold tire air pressure was 65#. Thnks for the info on my coach  and the links !
Idahored
 
I have an old Michelin inflation guide that shows a 7.50R16 as capable of 4940 lbs single and 8600 per dual when inflated to 65 psi. The Michelin RV tables show capacity per axle, so that 4940 is for two tires and the 8600 for four.  That's slightly less than the Firestones at 65 psi, so 65 is plenty.
 
dktool said:
DO NOT adjust the sector shaft adjuster, you will be asking for trouble. That is ONLY to be set with the box on a bench with nothing connected to it and with an inch pound torque wrench to spin the input shaft and set the pre-load on the sector shaft via the adjuster screw, and only after knowing how many inch pounds or turning resistance it should have.

Do the old school method of just turning the screw to eliminate play will result in a damaged box 9 out 0f 10 times.
That method worked for non-power assist boxes back in the 6o's but does not apply here.
Click to expand...

dktool gives great advice. He is probably a trained professional. Just for grins, ask those advocating adjusting the steering box what kind of back ground or training they have in auto/truck maintenance.
Steering boxes should not be tampered with by amateurs.

Richard
 
Gary RV_Wizard said:
Tire brand makes little difference, but tire size does. Were  the originals also 235/85R16?
Click to expand...

This is the confusing part, what is a Chevy P30 / P37 chassis doing with 16" wheels ? Should be 19" wheels.
The OP did not specify chassis brand, could this be a Ford ?
 
dktool said:
This is the confusing part, what is a Chevy P30 / P37 chassis doing with 16" wheels ? Should be 19" wheels.
The OP did not specify chassis brand, could this be a Ford ?
Click to expand...
A lot of older coachs on the P32 chassis had 16" wheels. My 80 Itasca 27 ft coach had 16" wheels, but it had a  heavier feel in the front end than the P32 with 19.5" wheels that I owned. My W22 has a much lighter feel than either of my P32s, but it has a Super Steer on it. 
 
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