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My first post stated that Bill Jensen stated that the original shocks are worn out at 35-40000 miles,I believe that this is accurate.I have a friend that installed Konis on his 1997 Vantari and he feels the same way that I do and that is that the original shocks are not any good.The original shocks have almost zero compression just as Steve stated,the difference in the Koni is the lack of roll or you might call it bounce,the coach is now almost flat in the corners and does not wander any more.
Steve is a racer so I know he will agree that the biggest influence on cornering flat is the sway bars. The shocks will definitely resist the lean in a corner but only for a very short period of time (seconds) as the bus tends to lean due to centrifugal force. Once the shocks are compressed they then resist the bus returning to the level condition because that is what shocks do. Depending on how they are valved their greatest resistance to movement might be compression or extension, my guess being these are biased towards resisting extension.
The biggest single difference between a later model coach and a 97 is the use of fast reacting ride height valves in the newer coaches and the time delay ride height valves in older models.
As soon as we put our coaches into a hard turn the body is going to lean (regardless of what shocks are in place). The rate at which it leans now depends upon the forces in the lean and the ability of the sway bar to resist the lean. As the coach leans the ride height valves in the rear begin doing their job. On the older time delay valves for a few seconds they don't do any thing. But the outer air bags compress while the air bags inside the turn extend. On newer coaches such as Jack's as soon as the air bags compress or extend the ride height valves are instantly dumping air from the inside bags and adding air to the outside bags to restore the coach to the level position. As soon as the bus exits the turn the forces on the air bags are removed and the ride height valves must again react to change the amount of air in the air bags so the coach continues to ride level. All the time however the sway bar is attempting to restore the coach to a level (side to side) position.
Prevost Mira Loma quoted me $817.50 for replacement of all OEM shocks on my XL 40 today. The OEMs are from Gabrielle. Service tech Luis, whom I really trust, says it is not worth the $$ to put Konis on the older buses. I was experiencing a lot of porpoise-ing and side to side sway on the old ones. Not sure how old they are as they were on there when I bought the bus. Will report results when I get it back.
Update: Today I installed Koni shocks set on Max on all axles. Took 3 1/2 hours and had to remove wheels on tag axle. Drove approx 60 miles on I-75 between summerfield and san antonio, fl. Moderate improvement in ride and handling. After 43,000 miles exterior of rubber bushings had deteriated but inside was still solid...coud have replaced just the bushings since the origional shocks still had acceptable resistence. However with everything apart I went forward with the installation of the Konis. There was no clearance problems with the tag axle shocks.
I put OEM shocks on our bus about 20,000 miles ago and it was the single best bang for the buck i've ever spent. My old ones evidently were spent. Had I known about the Koni's I would have put those. I will put those next. Regarding the price difference it's a no brainer. For less than the price of one tank of fuel you can justify the better shocks.
I drove my coach to Road Atlanta(500 miles)this past weekend to a vintage race,I now have more seat time with the Konis and they are as reported earlier Superior to the OEM shocks in ride,roll and in all other aspects of handling.My coach is much easier to drive in crosswinds and undulating road conditions,I am not chasing the wheel any more.
Was able to wangle 2 Koni's from Prevost Mira Loma. Man those puppies are hard to come by, if you're in a hurry. Installed today, but bus still at service center awaiting new dryer cartridge. Will see soon if it improves. Put Koni's on the front, and 6 new stiff Prevost black shocks on all others.
Ray
I replaced the front I am sure original OEMs with more of the same when the sway bar bushings were replaced. Amazing difference in ride and handling. Wonder how much more improvement the Koni's would make (if any) with my vintage coach, which is much lighter on the front end than some of the slide models and other XLII's.
Is the installation and clearance the same for a H3-45 as a XL1, 2 ? have 50,000 on my bus and was wondering, you know you get used to the ride and don't think about it. have not had any issues, such as swaying or up and down. but as a comparison I thought the old out house was fine till I tried an indoor facility!
I had Koni's installed on the front and left the old OEM's on the drive and tag for now. Drove it back to where I store it, maybe 30 miles and I can't say I noticed an appreciable difference in the feel, at best maybe a little firmer. We'll see how it feels on the way to Kerrville in a couple weeks.