terrible tracking after new tires installed

[retiredrlk1]

I have been reading about tracking all over this forum and can not figure out why my 2002 W22 will not drive right.

I have put one of omey's diy track bars on the rear and a davis tru track on the front. My michelin tires were 7 years old with no cracks but I changed them out from reading this forum. I put goodyear 245/75R 22.5 G670 rv TL14 on. They were installed by Camping World (an 8 hour job) and I could hardley hold it in the road on the 30 mile trip home. Wrong air pressure was main problem but still handled bad.

After reading all I could find on handling here, this is what I have done.
I have weighed it fully loaded as I travel (gas & water). I had the allignment set at a heavy truck shop. The first time they set it as follows:
camber +20min left +20 min rt
caster 2 1/8 2 1/2 Toe was +1/16
It still drove terrible so 3 months later I took it back and had it changed according to figures from someone on here to this forum:
camber +20 min caster 5 degrees each side and toe to +1/16"
Weights are lf 3790 95lb rf3450 95lb lr6075 92lb rr6150 92lb

What am I missing??

[gknott]

I believe your figure of + 1/16" toe in is actually a toed out condition. I have had two m/h and have had them both toed in to almost twice frtliner specs making them both a pleasure to drive.No more wondering around in the wind or following ruts.Meeting or passing trucks also less noticeable. This worked for me anyway.

[M&EM]

Quote:

Originally Posted by retiredrlk1 I have been reading about tracking all over this forum and can not figure out why my 2002 W22 will not drive right. I have put one of omey's diy track bars on the rear and a davis tru track on the front. My michelin tires were 7 years old with no cracks but I changed them out from reading this forum. I put goodyear 245/75R 22.5 G670 rv TL14 on. They were installed by Camping World (an 8 hour job) and I could hardley hold it in the road on the 30 mile trip home. Wrong air pressure was main problem but still handled bad. After reading all I could find on handling here, this is what I have done. I have weighed it fully loaded as I travel (gas & water). I had the allignment set at a heavy truck shop. The first time they set it as follows: camber +20min left +20 min rt caster 2 1/8 2 1/2 Toe was +1/16 It still drove terrible so 3 months later I took it back and had it changed according to figures from someone on here to this forum: camber +20 min caster 5 degrees each side and toe to +1/16" Weights are lf 3790 95lb rf3450 95lb lr6075 92lb rr6150 92lb What am I missing??

retiredrlk,

My guess is too much tire. From your axle weights it would seem the rear TP should be much lower then the 92 according to the Goodyear inflation chart. Likewise for the front pressures.

Having done all that you have indicated, do you know if rear axle thrust angle was checked?

On mine, I had all the same things added/done. The last 2 things included complete alignment plus thrust angle correction and addition of Saf T Plus centering device. Tracking was much improved.

[jimkate]

Did it steer worse immediately after replacing the Michelin tires with Goodyear G670 RV tires? I have not personally used them, but I've read that some regard the G670 as a terrible steer tire. Possibly try Michelin or Bridgestone on the front wheels?????

Yes, make sure the toe setting is toe-in. The 1/16" is probably minimum. Many set their toe-in at 1/8" for best handling.

[retiredrlk1]

Sorry for the late reply buy I had to go to bed ( heart problems). I found the inflation chart for the G670 and I read it to mean 70 lb. or 75 lb. at the most. If someone will give me the correct readings for the allignment, I will have it done again. The trouble started after I replaced the michelin tires with the goodyear. Thanks for the input and I am off to work now.

[edgray]

Quote:

Originally Posted by retiredrlk1 ....... I found the inflation chart for the G670 and I read it to mean 70 lb. or 75 lb. at the most.

RETIREDRLK: I suggest you get your coach axle weighed and then re-check the Goodyear pressure charts for the pressure needed to support the actual weights you are running. 70-75 PSI sounds VERY low to me for a W-22 chassis, but the scale will tell the tale.

I'd not spend any more money on alignments, etc until the tire pressure issue is eliminated.

Ed

[DriVer]

Quote:

Originally Posted by edgray I'd not spend any more money on alignments, etc until the tire pressure issue is eliminated.

I agree with this assessment.

[retiredrlk1]

I weighed the coach and car on the single scales in Ohio at the ralley last June. The chart for goodyear G670 245/75r rv is this:
single 3470---70lb. 3645---75lb.
double 3260---70lb 3425---75lb.
Is this not what you see for this tire?

[JonBrazel]

Try 80 PSI in the fronts and 70 PSI in the rears....that's what I come up with per Goodyears inflation chart for your individual corner weights.

[retiredrlk1]

Thanks Jon. After looking bask at the table, I see this. Do you think I need to add 5 lb. to this as some have stated?

[DriVer]

Quote:

Originally Posted by retiredrlk1 Thanks Jon. After looking bask at the table, I see this. Do you think I need to add 5 lb. to this as some have stated?

The additional 5 PSI buys you time between the air you have vs the air you need.

[M&EM]

Quote:

Originally Posted by retiredrlk1 Thanks Jon. After looking bask at the table, I see this. Do you think I need to add 5 lb. to this as some have stated?

Since tire pressure is too high according to the GY charts, why not go directly to the recommended pressures to see the effects. Then decide on the extra 5 psi. It may be the difference in ride/handling that decides for you.

If it were my coach I would get a second reading of axle weights at a certified scale to protect my tire investment.

Not sure why 5 psi extra is recommended. I use 3 different gauges to confirm pressure is consistent on all 3. I also check the tire pressures as a pre-check on every driving day.

Marty

[FreshAir]

I'm in no way a tire expert but your comments bring back memories of a simular experience I had when changing tires on a 2000 Bounder I had bought in 2004. I bought it in Tampa and drove it back to Utah and all was well, handled OK. The tires were Michelins and needed changing so I put on a set of Bridgestones which I was told, by several sources, were superior to the Michelins. Maybe so, but they never compared to the better ride and handeling of the Michelins. I have always believed the GY tire you have is an excellent RV tire and hope you find a solution to your problem. Please keep us informed as it is important to all of us RV folks. Thank's, look forward to heaing how it turns out for you.
Pat

[retiredrlk1]

I finally got to test drive about 15 miles after setting the pressure to 80lb front and 70lb rear. I did not rear improvement in the stearing but the ride was a lot softer. On a new concrete I85 section it ran straight with no problem. On secondary road with new asphalt, it wanted to follow the lay of the road and not go straight as the steering was set. I guess my next step would be the toe setting as one of you said looked like a toe out (+1/16)