Side to Side wander

[dmeck]

I have an 02 Georgie Boy Landau 34ft on a workhorse IFS front suspension. I know this question has been asked before but I am hoping to get some new advice. When I drive down a level road with no wind and I hold the steering wheel perfectly still my coach wanders a little to the right and back to the left but really never to much out of the lines. The coach does not pull it just has this side to side wander. The problem come when I get into a little wind and I have to correct for that it seems to get worse. I have made a few modifications: New Michelin tires run at 90lbs, new drag link, henderson rear trac bar, henderson bell cranks, new front springs and airbags, rear air bags. Weight is 6000 in front and 12000 in back. Any suggestions would be great!!!

[RV Wizard]

Was the alignment checked and set? How about the shocks; are they good?

[Ed-Sommers]

If it were me, I'd suspect inflation problems. I'd take the inflation to max allowable IAW sidewall info and see if that solves the problem. If so, then the correct pressure for you would be somewhere between 90 and max allowable pressure.

On my rig, I tried the proper pressure according to weight and it was terrible. More pressure solved my problem and seeing as how replacement on most RV,s are because of time, not wear, additional pressure is fine IMHO.

Ed

[dmeck]

I have had the front end aligned twice, the second time to the henderson supersteer specs which added more caster than workhorse specs I think. I have also added the supersteer sway bar spreader which did help overall driveability. I have added a safe t plus as well. Lots of money, labor and parts and still the wander continues. The most tire pressure I have used is 95lb in the front. I was worried about going any higher and it did not make a difference in the wandering. The shocks are the original bilstein shocks, I have not changed them because I have no problem with front end bounceing or excessive sway.
Workhorse IFS has to be the most talked about and worked on front end in the motorhome industry!!!
Any idea what the max tire pressure I could go to for 6000 lb front end with Michelin 19.5 XRV tires? Thanks for the help.

[hawg6]

Quote:

Originally Posted by dmeck I have had the front end aligned twice, the second time to the henderson supersteer specs which added more caster than workhorse specs I think. I have also added the supersteer sway bar spreader which did help overall driveability. I have added a safe t plus as well. Lots of money, labor and parts and still the wander continues. The most tire pressure I have used is 95lb in the front. I was worried about going any higher and it did not make a difference in the wandering. The shocks are the original bilstein shocks, I have not changed them because I have no problem with front end bounceing or excessive sway. Workhorse IFS has to be the most talked about and worked on front end in the motorhome industry!!! Any idea what the max tire pressure I could go to for 6000 lb front end with Michelin 19.5 XRV tires? Thanks for the help.

I went through the same sequence of events. The last change was to shim the caster to 5 degrees, which finally fixed my wandering.

[dmeck]

Thanks for the suggestion. The last alignment I had done they set the caster at 4.8 deg. on the left and 5.4 deg. on the right. When I had the alignment done I tried to take it in with it loaded as though I was going to be driving it on a trip. I think with the IFS any weigh change +/_ a few 100lbs in the back from water or maybe pulling a toad may take weight off the front end, transfering it towards the back and change the toe in settings, and this may cause the symptoms I am experiencing. I know from an alignment I had previously that was not done well and they had to much toe in that it drove really bad, like the front end was really light.

Just guessing at this point.

Has anyone tried to adjust the steering gear box with the workhorse IFS? And if so did it help at all? I was told by workhorse it is a counter clockwise turn of about 1/4 at a time to tighten.

[Max Hubrich]

dmeck,

I had a P-30, 454 chev and it did what you are describing. After two alignments, new shocks and a steer safe it still did the wandering. The wife got motion sickness from it.

I took it in a third time and an hour after I dropped it off, the tech called me to come get it. He said "no charge", I think it's fixed. He adjusted the "Saginaw steering gear box", just like you heard about. Only on my '86 chassis, it was a "clockwise" turn on the adjustment nut. He went a 1/2 turn and it made all the difference in the world. It drove like a different vehice after that.

I understand that the newer rigs have a left-handed thread, like you stated. Give it a try, what you got to lose?? He told me that if you go too far the steering will get "Squirrely".

Good luck,

[Marty too]

I would suggest to all folks, while most RV tires are listed at 120lbs max per weight, before doing a guess and/or taking someone else’s recommendation, check in the flat part of your rims to see if there is a stamping showing max air pressure for that rim. I’ve a notion that most steel type rims especially in 19.5 size have a stamp of 90 lbs as max air. It might be possible to go 10% over that 90 but I sure wouldn’t go above that in any case. On a previous coach, when I had the tires replaced, the tire guy pumped in 110lbs not knowing the rims were stamped at 90. When I discovered what he had done, I found out he had no knowledge about rim pressure. Needless to say, I had the pressure dropped to 90 until I could get home and recheck on my own. I have no idea about aluminum rims but they should be stamped also. This is just a word of caution.

Marty

[dmeck]

This is really the best forum site on RV's around. I have gotten more information and saved alot of money from the information from this site.

Thanks for all the help and I will keep working on the wandering issue.
It makes a long trip even longer when I can't relax for a minute.

I guess this problem is part of the P32 chasis and Workhorse.

[steve R]

I had a similar problem with my Workhorse W20 chassis. I was running the MAX tire pressure whichh was 95 psi. After weighting the motor home i lowered the tire pressure to the recommended pressure according to to weight of my motor home was 85 psi big improvement

[DGShaffer]

On another forum (RV.NET) I read a lot about this issue and there seems to be a brand of tires that was causing this, after people got rid of them they say it was like driving a new rig. You may want to do a search over there.

Here's one such thread

[dieselclacker]

You didn't mention what wheel base your chassis is. On short wheel based motorhomes with a lot of overhang from the rear axle back, tail wagging and wander is a problem.
I have owned two P-30 chassis motorhomes, a 30, and 32 foot. I have found that loading can be critical, especially if the coach has a lot of rear overhang. On my last 1987 model 32 footer, I had a larger gas tank installed, and could feel a difference in the way it drove after a fill up. As you said weight transfer from front to rear makes the front lighter, which can add to the problem.
The specs I finally ended up using on the front end alignment were s imilar to yours. I ran zero camber, 5 degrees positive caster, and a full 1/4 inch total toe-in. Also give the tie rod ends a really good inspection for wear. As for tire pressure, I would not recommend using over 5 lbs above what the Michelin chart recommends for the weight you are carrying on the front axle, over inflation decreases the footprint size and rolling resistance, as does not enough toe-in, and is not good for a wandering condition. Also give those tires a good look for any uneven wear that could cause a handling problem.
The steering box adjustment is used just to take up wear clearance within the steering box. It should be adjusted to zero clearance without any binding when turning the steering wheel or shaft.

Dieselclacker

[Gary RVRoamer]

Just for the record, the Workhorse W20 and W22 does NOT have an IFS (Independent Front Suspension) - it is a solid axle.

[Steve Ownby]

It appears that you have spent a lot of time and considerable $$$ on your wandering problem. I hope you have seen some improvement for your efforts. You seem to have thought of and addressed the most likely areas a problem could be in.

Measure your over all length and measure your wheelbase. Divide the wheelbase by the length & see what % your wheelbase is of your total length. If you are down around 50-53% then you will likely always have some measure of "squirrelly" handling. You really have to get up above 55% to be able to achieve a rock solid tracking ability.

I don't agree with everything rv.org says but they appear to be on target with this.

Good luck & safe travels,
Steve O