SUSPENSION ADJUSTMENT PART 3, DRIVE AXLE ADJUSTMENT
Posted: Wed Oct 29, 2008 1:20 pm
Please make sure to follow the instructions in the order that has been described. Do not skip the factory designed steps.
After you have the bogies set to the desired weights, you will next adjust the drive axle. You will be adjusting the drive axle for height.
The first thing you want to do is park your coach on a level concrete surface. Then, using one of the 12 ton bottle jacks, raise the front end of the coach at the front center jack point until both front wheels just clear the ground. The reason for this is because we want to eliminate the front end, which has not been set yet, from hindering the height readings at the drive axle.
Next, measure the distance from the edge of each drive axle aluminum flare through the centerline of the wheel to the ground. The proper setting should be 47-48 inches. Record the measurements making sure you note right and left so you do not forget what you started with. Using the measurements, determine how much you need to adjust each side.
Next, go back to the front and let the 12 ton bottle jack down. Then take the 12 ton bottle jack to the rear and jack up the body of the coach on the side that is sitting the lowest or needs the most adjustment. I always like to start with the side that is sitting the lowest just in case you cannot raise the coach to the desired ride height.
Jack up the body as far as possible to relieve the suspension. If you have levelers on the coach and they have enough travel, you may use them to raise the body of the coach. Place jack stands under the coach for safety.
Each drive torsion has two adjustment rods. Make sure you lubricate them thoroughly and clean the threads with a wire brush. Measure the threads at the bottom of the adjustment rods to determine whether or not you have enough adjustment left to achieve the height desired. For every 1 inch of threads that you have left, you will be able to raise the coach approximately 2 inches.
NOTE: Your adjustment rods from front to rear on each drive torsion should have an equal amount of threads showing before you start and after you finish. If they have not been adjusted equally, then you are putting the majority of the load on one arm and transmitting that load to one end of the torsion spring. This may cause the torsion housing to crack and then you will end up replacing the torsion bar.
The next step is to back off the lower nut on the adjustment rods using your 1-7/8" wrench. For example, if you need to raise the coach 2 inches, then back off the nut 1 inch.
Next, make your adjustments with the 1-7/8 inch wrench by turning the upper nut on the adjustment rods clockwise forcing the adjustment arm down until it bottoms out on the lower nuts. Alternate back and forth from front to rear adjustment rods. You may want to remove the duals so that you can get a bigger swing each time with the wrench.
Do the same process on the reverse side. When complete, remove all tools and jacks. Start the coach up and move it forward and back hitting the brakes hard. This shakes the coach up and allows the torsion bars to settle in.
Finally, jack up the front end again at the center jack point until the wheels just clear the ground. Go back to the rear and check the measurement at the drive axle wheel flares. If you have achieved the desired height on both sides, then you're done.
If not, then repeat the process 
Dan
After you have the bogies set to the desired weights, you will next adjust the drive axle. You will be adjusting the drive axle for height.
The first thing you want to do is park your coach on a level concrete surface. Then, using one of the 12 ton bottle jacks, raise the front end of the coach at the front center jack point until both front wheels just clear the ground. The reason for this is because we want to eliminate the front end, which has not been set yet, from hindering the height readings at the drive axle.
Next, measure the distance from the edge of each drive axle aluminum flare through the centerline of the wheel to the ground. The proper setting should be 47-48 inches. Record the measurements making sure you note right and left so you do not forget what you started with. Using the measurements, determine how much you need to adjust each side.
Next, go back to the front and let the 12 ton bottle jack down. Then take the 12 ton bottle jack to the rear and jack up the body of the coach on the side that is sitting the lowest or needs the most adjustment. I always like to start with the side that is sitting the lowest just in case you cannot raise the coach to the desired ride height.
Jack up the body as far as possible to relieve the suspension. If you have levelers on the coach and they have enough travel, you may use them to raise the body of the coach. Place jack stands under the coach for safety.
Each drive torsion has two adjustment rods. Make sure you lubricate them thoroughly and clean the threads with a wire brush. Measure the threads at the bottom of the adjustment rods to determine whether or not you have enough adjustment left to achieve the height desired. For every 1 inch of threads that you have left, you will be able to raise the coach approximately 2 inches.
NOTE: Your adjustment rods from front to rear on each drive torsion should have an equal amount of threads showing before you start and after you finish. If they have not been adjusted equally, then you are putting the majority of the load on one arm and transmitting that load to one end of the torsion spring. This may cause the torsion housing to crack and then you will end up replacing the torsion bar.
The next step is to back off the lower nut on the adjustment rods using your 1-7/8" wrench. For example, if you need to raise the coach 2 inches, then back off the nut 1 inch.
Next, make your adjustments with the 1-7/8 inch wrench by turning the upper nut on the adjustment rods clockwise forcing the adjustment arm down until it bottoms out on the lower nuts. Alternate back and forth from front to rear adjustment rods. You may want to remove the duals so that you can get a bigger swing each time with the wrench.
Do the same process on the reverse side. When complete, remove all tools and jacks. Start the coach up and move it forward and back hitting the brakes hard. This shakes the coach up and allows the torsion bars to settle in.
Finally, jack up the front end again at the center jack point until the wheels just clear the ground. Go back to the rear and check the measurement at the drive axle wheel flares. If you have achieved the desired height on both sides, then you're done.
If not, then repeat the process Dan