I have noticed that our 21RB sits low on the port side. I crawled under and measured and on the starboard there was 3 1/2 inches of axle
to frame clearance and the port was 2 3/4 inches. That combined with the fact that the rig wants to drag its' rear in any kind of unusual hump or hollow situation. Fuel station entrance exits always had to be evaluated as to whether it would cause dragging. Traveling on undeveloped roads and maneuvering into uneven parking is less than optimal. I decided to switch it from underslung to overslung suspension.
I found a distributor for Standens axle
components in Indiana and they had 4 #125-5 springs and they are on the way. I put a stringline on the axles and they do have a camber built into them so I have 4 spring perches coming from etrailer. I sold
my welder before I moved to Florida so I will have to hire a mobile welding service to stop by and weld them after I build a jig to control their placement. Today I removed the brake backing plates and found good news. First the brake components are all original Dexter brand and look to be in almost "like new" condition and the bolt pattern is concentric so flipping 180 degrees is simple.
The only surprise so far was that the installer of the holding tank enclosure got it a little too far forward and on the port side the bolt for the rear spring
mount could not back out. I had to use a vibro saw to cut out a relief and will use an adhesive like 3M 4200 to replace the piece after the bolt is back in.
I know others have done this and would like to hear from anyone that has advice or experience that may help me through this.