Suspension Creak

[jack14r]

That is great,at least you are under on the front axle.Most weigh with waste tanks empty and fuel and fresh water full,also most Flying J scales can weigh 3 axles,that way you know how to adjust air in the drive and tag.

[truk4u]

Jack,

Adjust air in the tag and drive? No understand Kimosabe..

[jack14r]

I should have said drive tires,tag tires.

[truk4u]

I know, I was just pulling your chain!

[Prevost.Rick]

a couple of tidbits ,i never see age of tires,brought up when we talk weights ,pressures,u can have proper air ,old tires and still be setting on the side of the road,it is extremely important to get the date codes off of your tires(most of the time on the inside of the tires)because of the intro of slides and the addition of all the acc.the coaches got heavier ,the the axle uprating that was done by putting 125lbs of air in the 315s,and raising chassis air pressure,for the brakes,to get to a 17200 lbs axle,and many coaches were over this so if you have a old set of tires with over 90 % air(130lbs max) on a hot road ,the tire rating will not be the same as when the tire was new,they did,nt upgrade any steering componants,so that puts stress on the components,and shortens there life this thread is talking about this now so the shock that is factory may need upgraded with this in mind ,there are 06 xl2 out there with 03 365 tires on them,i,ve had cust. lose a tire with proper air pressure(the tread came off without losing air pressure) it does,nt matter steer or tag ,one both ,it seems this year tire if you can have too much air he had ck,d tires before leaving (he,d already lost one on pryor trip)115 to 120 lbs he drove from naples thru jacksonville at 67 mph and it was 87 degree at the time ,he lost the tread i had him ck air pressure it ,135lbs so ck your year of tire,weight of coach ,and put speed rating,and watch tag pressure,with your tag down it put about 1500lbs to your front axle(when weighing front axle dump tag to find out)so the more air in your tag tire the more front axle can weigh,so if you are heavy on your front axle,you can make it worst

[jack14r]

Rick,I am going to try this when I get home next week,I have 100 Lbs in the tag,if I reduce it to 85 do you think that it will show on the scales?What you are saying does make sense.

[Jon Wehrenberg]

Just to stir the pot I'll bet it makes no difference. If you could change the air pressure in the tag axle air bags it would make a very big difference. I am not advocating that or suggesting anyone modify their coach to do that because when that is done it affects other things.

Post the change Jack, but try to hit the exact same points on the scales, or better yet, pull on them with 100 PSI in the tag, and without moving drop the pressure to 85 and see if it shows up. The reason I bet against it is because while the rolling radius may change by a fraction of an inch, the tag axle air bags will adjust for that fractional change because the ride height valves are sensed ahead of the drive axle and not at the tag.

[BoaterAl]

What about ride height, and I'm thinking with the front axle as it take most of the abuse. If this is in specs which should be about 11 3/4 front and 11 5/8-11 3/4 rear, how will that effect the ride and air pressure ? With my weights as determined on the scale a few days ago (17770 frt and 34700 rear) what should my tires pressure be ? Presently at 105-95-85
That is my next project to check ride height and I already know the front bag is a fraction under 11 inch and of course this does effect the overall ride of the bus.
After playing around with ride height,shocks, air pressure on the Country Coach Affinity what really worked was dropping the overall ride height of the coach 1 inch. I realized this when investigating the shock extension travel. When set to max bag CC factory specs there was a possibility of breaking a tower bolt. The long and short of this story was a better ride and nearly elimination of rear end wine. IMHO I think the specs were wrong on the coach from the get go. I never had any more ride issues with that coach. Even the buyer remarked how different my Affinity road, steered compared to another he was considering to buy. Many CC owners wear out the right frt tire at an alarming low mile point. I know why.
Got a little of tract and probably more useless info
AL
2005 Marathon XLII 2/s

[jack14r]

Jon,I know from race cars that air pressure front to rear will not change the weight,at the place I weigh you must exit the scales to be re-weighed.I will change the weight and then weigh it again,I know that the air bags would change it but I hope the tire pressure will also,I will report the results next week,I am in France now.

[Jon Wehrenberg]

Al, the alignment on our coaches is done at the ride height and if we adjust afterwards it "MAY" impact the alignment. I do know that as the coach is raised towards its high position in the front the steering and handling are considerably compromised. I do not know at what increase in height the changes begin to be felt. I am sure fractions of an inch will have no measurable impact.

If you are looking for a "softer" ride you are getting into an engineering issue. For example, the valving in our shocks and the diameter of the air bags control how harsh a bump feels. Lowering the bus ride height in essence reduces air bag pressure so the bumps will be less harsh, but in doing so the risk of the bus bottoming increases. Conversely, raising the ride height increases the air bag pressure making bumps feel more harsh and risking a rebound to the full extension of the suspension and as you surmise damaging the shock eyes or the attach bolts.

The way our air bags are engineered, by setting the bus at the correct height we have presumably equal up and down travel and the steering geometry is optimised for that position. When we adjust heights (actually by lowering or increasing air bag pressure) we depart from that ideal. I would make sure the bus is set within specs and use adjustable shocks that you can play with to dial in the ride that suits your needs.

As to tire pressures they are totally dependent upon the tire size and the weights they carry. This chart should help you find the right settings:

http://www.michelintruck.com/micheli...ion-tables.jsp