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SUSPENSION ADJUSTMENT PART 1,CHECK BUS HEIGHT & BOGIE WEIGHT

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Please make sure to follow the instructions in the order that has been described. Do not skip the factory designed steps.

Alright, here we go guys, Suspension Adjustment Part 1 for Eagle Coaches.

I am going to break this up into 3 or 4 parts so that no one gets overwhelmed by this procedure. This will allow you to ask questions that you want answers to and to help you understand the procedure before moving on.

SUSPENSION ADJUSTMENT FOR EAGLE COACHES

SPECIAL TOOLS NEEDED FOR THIS PROCEDURE

3 each 12 TON BOTTLE JACKS
1 each 8 TON BOTTLE JACK W/3000 PSI GAUGE
1 each 1-7/8" WRENCH
LOTS OF PENETRANT

Make sure your tires are the correct size and properly inflated. Prior to starting any adjustment, make sure you lubricate all areas of adjustment using a good penetrant.

The correct ride height measured from the aluminum wheel flare edge down through the centerline of the wheel to the ground, should be 48 inches. Measuring from the bottom of the baggage bay tubing to the ground should be 14 to 14-1/2 inches. If you use the latter measurement, make sure you are on level ground. These are the measurements that were used for an empty seated bus. Since motor homes are carrying a load at all times, you may choose to set them an inch lower, 47 inches or 13 to 13-1/2 inches.

For every inch of threads on the adjustment rods, you will be able to raise the coach approximately 2 inches. Make sure you have enough adjustment to achieve the ride height desired. If you are out of adjustment, it may be time to replace that torsion bar. You can install longer adjustment rods in lieu of replacing the torsion bar; however, this may be a short term cure as the torsion bar may have already seen its better days.

Because of the geometry of the way a torsion bar with its fixing arms set in the bus, it is important not to let the coach settle to low before adjusting, as this will put more strain on your torsion springs and cause them to prematurely wear out. You want to keep the rubber inside the torsion bar wound up tight, kind of like stretching a rubber band.

The order of adjustment starts with the bogie or tag axle, then the drive, and finally the front. You will be adjusting the bogie or tag axle for weight, the drive axle for height and the front axle for weight and height.

STEP ONE, CHECKING THE BOGIE OR TAG AXLE FOR WEIGHT

You start be jacking the bus up to the correct ride height desired using the three 12 ton bottle jacks. Place two of the jacks at the rear outer most jack points and one at the front center jack point. Make sure you dial in the height desired and recheck before moving on.

The reason we are jacking the bus up with bottle jacks is because we want to find out what the bogie or tag axles are carrying at the correct ride height before making our actual adjustment. If you adjust the coach up to the correct height using the adjustment rods and then try to adjust the weight on the bogie or tag axle, you will change the ride height and then end up reversing your adjustment. This eliminates that extra work.

Next, take the 8 ton bottle jack w/pressure gauge installed to it and jack up the bogie or tag wheels underneath the end of the fixing arm as if you were going to change a tire. Jack until the tire just clears the ground. Read the pressure gauge. Because your gauge reads in psi, then you will double that figure to find the correct weight. Example, if your gauge reads 1500 psi, then you would double that and 3000 lbs. would be the weight carried on that axle. The correct weight should be 3000 to 3500 lbs. per side. Motor homes may want to carry a higher weight since they are carrying a full load all the time. It is important that you do not carry much more than 4000 lbs. per side since each bogie or tag axle torsion bars are rated for 5000 lbs. each. The reason you do not want to set it to the maximum is that you must leave room for increased loads when the coach is in motion. If you go through a large dip in the road and the rear of the coach comes down, it is adding weight to the bogie or tag each time you do that and if set to the maximum, you will possibly bend the inner tube of the torsion bar which will knock the wheel out of alignment and you will end up having to replace the torsion bar at that point.

If you are lucky and the weights are correct and no adjustment is needed, then you have accomplished the easy part of the procedure. If you are not so lucky and the weights need to be adjusted, then the fun will begin on my next post.
Last edited by SmoothJazz on Mon Aug 10, 2009 5:09 am, edited 7 times in total.
Daniel Lenz
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Re: SUSPENSION ADJUSTMENT PART 1
Fri Oct 17, 2008 9:05 am

Dan Hi and welcome ,I found your tech topic Very interesting and useful.Reading thru it and having read the manual on the subject every thing you mentioned was spot on.I was so interested in this area that I felt compelled to run out with my tap measure to check the height on my 15 which was well within the box for the correct ride height.Well it's one less thing to deal with for me as we attempt to reassemble every thing in the engine compart ment.

I truly consider myself to be very fortunate to have come to know alot of eagle owners who for one are very knowlegable about their eagles,very compassionate toward other eagle owners in need of info or help.Traveling home from Illinois with my first eagle was very exiting for me a day I dreamed of for most of my adult life.Unfortunatly a fuel pump went out leaving me stranded in Amarillo TX,calling every repair shop in the area it was becoming apparent that I was in deep DOO DOO until I remembered the web site for silver eagle manufacturing.With no where else to turn I called my wife Cheryl on the phone and had her get you guy's number for me .Within the first 3 min of the conversation with Craig I started to feel a sense of relief that this problem was going to be resolved .

Thanks to craig' knowlege and compassion for the spot I was in ,I was able to get back on the road safely and confidantly.Heck Craig even went so far as to keep in touch with me thru out the remainder of my trip home .Thats what I call support ,and it is one of the many reasons I have become a proud and loyal eagle owner ,by the way CRAIG I owe you A fuel pump buddy.Although the pump was only the first of many problems to follow I could not have gotten thru them with out the help of many other proud and devoted eagle owners that had already traveled down the same road I was on

So with that I will conclude by saying Eagle owners as well as the builders are some of the greatest folks I have had the pleasure to have met. My hat is off to you all!

GOD bless and continued success to tou all.

Van
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Re: SUSPENSION ADJUSTMENT PART 1
Thu Oct 23, 2008 9:32 pm

Dan,
Great information I hope I will finally be setting on my Eagle next summer. I have one other question on the measuring of the bus height, is this height adjustment done when the bus has been fully loaded or empty? Do we have our tanks of fuel and water on board etc.?? If we adjust our bus height to the maxium height when empty, does this change any of our adjustment height when fully loaded? I still have in my mind a plan to do like Sonnie did and put additional air bags on but that has not been actually done as yet but I find this feature on Sonnie's bus so imaginative & creative. Keep the great information coming, This board will be so darn educational and with no controversary about other models of buses concerning any kind of Eagle adjustments.

Do you guys also have any information on checking alignment of our bus at the front end and the bogie alignment. I mean tips that you recommend and any time some of these things are discussed if we can post some photos of explanation if possible. Tips to prevent us from making costly or dangerous mistakes is really appreciated, I try my hardest to do that. Many are affraid or do not want to admit to making mistakes and have it known but I hang all my mistakes right out there to prevent anyone else from falling in the same situation I did & hope I helped. I did that with my Bus Video that took 5 months to make.
Thanks again Dan and anyone who does a thorough educational post in the past and future.
Gary
Owner of the "Rustless Money Pit" 1973 Model 05 Eagle.
http://busconverter101.com for instructional video
Eaglesinternational bb'd best site for Eagle owners to receive information.
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Re: SUSPENSION ADJUSTMENT PART 1
Fri Oct 24, 2008 8:07 am

Gary
The one thing that I do not like about the Eagle is they didnot but enough caster in the front end. I am sure that is because in the days of no power steering less caster is better. If your bus wanders a little bit in my mind that is caused by to little caster. I have spent a lot of time on trying to get more caster in my 05. I have tryed to but more shims in the front of the upper A arm and move the Torsilastic foward. But you can only but so much before you start to but things in a bind. Remember when you adjust the caster the large nut that holds the king pin assm. has to be lose and the king pin assm. has to be free. I am not sure what model bus you have but I know the 01's are a little different and Kaiser in oregon has some parts to help with the caster. The tag is adjusted using shims. I think Jefferson has some. Also call Silver Eagle to see if they have any. Back to caster I know Craig reads this board and I hope he will build the new buses with more caster in them. The new trucks have as high as 4 and 5 %. I have tryed every thing I know and have only been able to get 1 1/2 % in mine.

Thank You Wayne
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Re: SUSPENSION ADJUSTMENT PART 1
Fri Oct 24, 2008 8:22 am

Gary,

The height adjustment should be done when the coach is fully loaded and full of water and fuel. If you adjust before loading the coach you will lose some of the ride height after loading and may have an unlevel coach. It is important to distribute the weight in your coach as evenly as possible and make sure you do not overload the front end. Also, you should make sure you leave access to the front baggage bay and spare tire compartment so if you ever need to change a front torsion bar, you will have access to the shackle bolts.

Make sure you adjust the suspension to the desired height prior to doing any alignment. The height adjustment can change your alignment, therefore, it is not only important to align your coach after the height adjustment, but also to maintain your ride height to prevent premature tire wear.

Alignment has been moved to a separate topic.

Dan
Last edited by SmoothJazz on Fri Oct 24, 2008 12:18 pm, edited 1 time in total.
Daniel Lenz
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Re: SUSPENSION ADJUSTMENT PART 1
Fri Oct 24, 2008 9:01 am

Dan, on your list of tools what is the 2 inch wrench for
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Re: SUSPENSION ADJUSTMENT PART 1
Fri Oct 24, 2008 9:22 am

Clifford,

It should be a 1-7/8" open end wrench which is used for adjusting the drive axle pushrods and the front. My apologies for posting a 2" wrench, don't know what I was thinking there.

Dan
Daniel Lenz
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Re: SUSPENSION ADJUSTMENT PART 1
Sat Oct 25, 2008 8:33 am

A couple of thoughts about the 1 7/8 wrench (Dan, thanks for correcting - I thought my tired old brain had skipped a gear). First, ask the price before you buy :D . I went into NAPA and thought how much can a wrench cost. Well, it was over $100 as I recall. We are not using the full strength of the wrench (does take a ton of force, but not so much as to cause a fracture of a "cheaper" wrench), so look around for a non-brand name.

Next, if you don't have a pit, you will find that the length of the 1 7/8 wrench will make the amount of "swing" limited. It took some deep breathing, but I cut my $$$$$ wrench in two with the open end being about 6 inches as I recall. You can then use a smaller open end wrench (using closed end) as the leverage arm. Seemed to make things easier for me.

A couple of more thoughts. When I adjusted my suspension, I soaked the threads a lot before I started, but it was still very difficult to move the rod. I found that even with the total weight off the suspension and the weight of the suspension working in my favor, It was still required a lot of force to turn the inside nut (to raise the coach you have to move the arm farther out on the threads). I found that the rod tended to bind in the sleeve of the arm. That sleeve rotates in the arm, so be sure the shafts of the sleeve are well lubricated. Even with that, I had to hit the sleeve every so many turns of the nut to relieve the binding.

On the bogey, you must remove the arm to move the splines on the shaft. Removing the arm is a real challenge. It is a split collar and Eagle is pretty clear not to spread the collar with a drift. I made a puller with chain and a hydraulic jack. I show a picture of the set-up at: http://www.rvsafetysystems.com/busproject3.htm. Photo is a thumbnail, so click on it to see a larger picture. Folks will tell you that a hydraulic jack will not work in a horizontal position. It will if you orient the jack so that the reservoir is on the bottom (my memory is that it was on the top, but the photo shows it on the bottom if one way does not work, try the other). Also be sure that the jack reservoir is at very full.

I think Dan probably mentioned it, but each spline change the loading of that bogey by 500 pounds. It is really important to do the boey. I would guess that the owners of my bus (Houston Metro) adjusted the front and rear at least once, but not the bogey. I weighed my bus empty on the way home and the front axle was close to being at the limit EMPTY :o . I had to adjust the bogeys five splines to get the loading correct!! That really took a load off the front axle. Scale readings show that I am pretty darn close to the factory load balance with the bus approaching the 38K GVW limit.

Jim
Jim Shepherd
Evergreen, CO
'85 Eagle 10 with Series 60 & Eaton AutoShift 10 speed transmission - not at all fancy, but fully functional
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I changed the title of this thread for easy reference.

Dan
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The 12 ton jacks are of course easy to find, but where do I find an 8 ton with a 3000 lbs gauge? I have done some searching online and found something about jacks that have a port tapped into the side for the gauge, will any 8 ton hydraulic jack work, if I tap a hole in the side? Or is that something that should be done by the manufacturer?
If so what is a good source for them?
Only my rear right wheel is at 47" and I am fairly empty still. The others range from about 3" to over 5" lower. Lowest being drivers side bogie axle.
Being that my bogie is off that far already should I start to work on getting it closer to where it should be before I start loading it so that I limit the stress on the front and rear axles? Or do I get everything set inside and then do all of my adjustments at once?
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