Caster Adjustment And Specs: 1998 Beaver 8 Bag Suspension

[Glenns72pc]

I have a 1998 beaver 8 air bag magnum chassis The RV is a constant hand full at speeds over 60 mph the ride height is at specs. The toe is on the money good shocks and all front parts are good. Also have added a Blue Ox steering damper. Tire psi is matched to the vehicle weight. New tires SO what is going on? I know from my car and light truck experience caster place a roll in tracking or KPI not adjustable on this unit ! But if you change the back or front ride height it will change this angle! What do you think any ideas.

[wolfe10]

Glenns,

Welcome to the FMCA Forum.

You have a solid front axle. So, caster is adjusted with wedge shaped shims above the axle. Any truck alignment shop can handle this-- it is basically a standard truck solid front axle with a different suspension above it.

Definitely do NOT change ride height to alter caster. You will take out your transmission output shaft and likely shocks if you adjust it enough to affect caster.

Also, what steering box do you have? If the Sheppard M100, they have a lot of "on center" play. It can be taken out by blueprinting the steering box.

Assume your tire pressure is appropriate for your actual "going down the road" weight, not necessarily the same as on the GVWR sticker.

Lastly, new tires require a break in period before they loose their "squirm".

[Glenns72pc]

How is a steering box blueprinted ?

[Glenns72pc]

Where can the caster specs or KPI be found for this coach ?

[hermanmullins]

Glenn,

Contact your Coach Mfg. They can give you the alignment specifications. As Brett said any good truck alignment shop can set your coach to the factory specs.

Herman

[wolfe10]

How is a steering box blueprinted ?

No first hand experience with them, but I know Henderson, Precision Alignment, etc recommend them: http://www.redheadsteeringgears.com/

[obedb]

Based on what you describe and the age of your rv you may need your steering gear or box adjusted. Many shops take it off of the unit to adjust it. They go by the book using sensitive torque measurements as they adjust it. It needs to centered to be properly adjusted. However when the gear is remounted if the vehicle does not have an adjustable drag link then the effort is wasted. The steering wheel should be turned to one stop/say counter clockwise and then carefully count the turns or fractions to the clockwise stop/ divide the result by two and turn the wheel in this case back clockwise that amount. The gear is now centered, but if there is no adjustable drag link on the unit as I, said time and money is for naught. Your motorhome will still wander going straight down the road because the gear will have to be taken off center to attach the drag link. Positive caster makes a vehicle handle better only if the steering gear is properly adjusted and reinstalled centered. I learned to adjust them knowing a talented no nonsense can do mechanic. I have used the method described with the wheels off of the ground and centered, gear or box still in place, and adjustable drag link unattached. Properly done the steering wheel may need to be removed and recentered.

FMCA # F105607 Call if you like.

[obedb]

Adjustable drag links seem to less and less common today. Even on 18 wheelers. Back in the day trucks came with a field adjustable steering gear and the frame next to the gear had a hole in it to get to the adjuster. Adjustable draglinks were also the norm. I have never had to reposition the pitman arm on the box, but a good front end man would have the tool to reposition the pitman arm after the steering wheel has been centered by counting lock to lock and dividing by 2. If you have a smart wheel you may not want it messed with.

I just reread your post. Thought your caster had been checked. Find a good alignment shop that will work on motorhomes. Let them check everything out for good working order or possible road damage. You do need some positive caster for good handling, and specs vary. I would spend the money on steering gear adjustment.

[dkreuzen]

The Sheppard steering gears are not adjustable, they need to be replaced with a TRW gear.

For a lengthy explanation of the swap see: http://www.irv2.com/forums/f115/steering-box-play-sheppard-m100-shim-or-swap-for-a-trw-210152.html

[obedb]

NOW that really hurts!!! Guess you will just have to learn to drive 55. I wouldn't though. If a good shop told me that it was probably the gear, I would replace it. Why would a premium coach builder put on an important part that can't serve their customer for the long haul?

Motorhomes are a hodgepodge.

[hermanmullins]

ObedB,

You are correct about Motor Homes. They are a mixture of available parts from many areas. A steering unit is one of the most serious parts in a coach.

I would like to know how many of these units have failed. It may be a very small number.

However I would hate to guess the cost of a Motor Home if they didn't go with best and most cost effective parts available.

Besides if we didn't have our coaches to work on just think what the DW would have us doing. I myself would rather work on my coach then move furniture, hang pictures and many other thing she can think of.

"Sorry Dear I would love to help but I have to get the Coach Fixed" Whew, that was close.

Herman

[obedb]

I spent part of my trucking career as an owner operator and a buddy of mine who owned an older rig made the observation that with your own truck, you are either in them or under them. Mine was much newer, but while doing PMs, I got to know what even a newer rig looks like from underneath. I don't mind working on my 2003 Phaeton and you are right, it is a good way to sneak away to the storage lot when we are home. My DW is not computer literate or I would not be writing this.

[obedb]

I would like to know how this poorly handling Beaver Coach problem is remedied. It could help members out with similar symptoms. I hope that Glenn will let us know how he solves things and about what it costs.

Herman/ You obviously have a great sense of humor and I applaud that. Mine isn't bad. BUT!! We bought a new Georgie Boy 34 in 1988 with problems from the gitgo.

So when we bought a newer DP built by a respected manufacturer, we expected greater reliability. Ours has some issues and I observe that owners of other brands also do. Is there evolution or just the same old same old with more expensive features? We still love our comfort in this unit. We hope that we can continue to afford that comfort.

[manholt]

Little things like slides and electronics added to the problems we have always had in my RV life. Bigger engines and heavier chassis didn't help! Some changes have been a blessing...I still shudder at the thought of carrying (2) 150 gallon fuel tanks on a 30 foot Apollo! We got better regulations and radial tires, etc. So, to answer your question, I would say a little of both evolution and same old!

We must also remember that everything out there in Class A, C or B, unless it's a Custom built coach, is a cookie cutter build.

Carl C.

10' AMC Tradition 45'

Jeep Wrangler