Rancho Shocks

[Tcash]

[raygreenwood]

The Rancho 9000's are a good product. They are well made. Whether they will last or not....depends on what their baseline valving was set up for....not to be confused on what you can adjust it up to with the dial.

If the weight and leverage of the original application was higher than what your bus is putting on it....they should do fine and last quite a while. As long as the overall rebound and compression resistance is not too high for the bus they will be fine.

If however the original load application was coupled with a very large spring....bearing in mind that shocks are dampers for suspension travel...and are not configured to "BE" the suspension.....then you can have lifespan problems.

I had a set of RS 9000's on my 412 back in the late 90's. I did not have enough knowledge/experience to grasp the physics at work. The RS 9000 model that "fit"....meaning correct stroke and physical size...was from teh back end of either a Ford or Chevy pickup application. I figured...heck...with the load capability of that behemoth compared to my light car it would be no sweat.

They started out on dial position 2 IIRC...great ride and control. Over about 6 months....to keep that level of ride control...I slowly had to creep up through about level 6 or 7. By about 10 months....I was at level 9 and they started leaking.

I went back to purpose made KYB's. I starting talking to a suspension guy at the off-road shop taht sold me the Rancho's....just trying to figure out why they crapped out so quick....because we both knew people that have run them for years on trucks with a great lifespsan.

He took a look under my car....and noted...damn!...your trailing wishbones have nearly a 30" span between the pivot/mounting point and the shock mounting point....and all of the engine and transaxle rate is right on the shock mount axis.
This means that while the travel distance of the shock rod is not extreme..... the leverage and the SPEED RATE of the shock rod movement was far more than what you would find on a pickup.....and the even bigger factor was that the pickup this was originally meant to go on....had a HUGE leaf spring....compared to my relatively dinky coil spring.

So the truck suspension was so over sprung for load capability that teh shocks did not have to work that hard.

The leverage and travel rate on my suspension literally beat them to death.

Time will tell on yours. But they do work well. Its also to be expected that as they break in...you will need to move up a notch or two. Thats normal...but if they slowly start to need increases over a rather short number of miles....they may be mismatched. Ray