I have a set of Koni red tops, used, that I'm trying to evaluate. They have a massive amount of rebound damping which is adjustable. They have zero compression damping. Is this correct for this shock?
Also, if anyone can contrast this with Koni gold shocks, I'd be interested in hearing the comparison.
Your shocks have failed. The Koni FSD (gold) shocks have firmer compression damping than the originals so they give a little rougher ride over small road surface bumps, but MUCH better control over large road surface changes. Most of us much prefer the FSD's.
Yes, there is many times more dampening on rebound than on compression on the Koni adjustable shocks.
Agree, zero on compression suggests failure.
Chuck I adjusted those shocks twice. Compression worked well enough to ride sharply across square edged freeway joints.
They are not turned up as far as possible.
The single internal circuit is not as sophisticated as needed to best control both high speed and slow speed compression dampening hence the dual circuit Koni golds I finally imstalled.
You mentioned worn Bilsteins if memory serves me?
These should work much better IMO.
The air bags themselves obviously are part of the compression dampening side and a smaller part of the rebound side.
Your 295 should benefit from these shocks.
Worked on mine just not a well as I needed on so cal concrete block freeways.
It took a $4k set of 7610 pound rated Michelin Xza-3+'s run at 97/87 plus the gold FSD's to better address bad LA roads ride quality.
They worked on mine. Soft. Turned up on coach once. Better. Turned up again. Best. No leaks.
The dual circuit allowed high speed compression spikes to go around the valving shim stacks.
Smooth roads the turned up red tops worked well.
FSD'S and the highest load rated "H" run at the lower pressure then possible gave a much improved ride quality here on the bad freeways.
The compression circuit does work but only on high speed hits. Very little low speed compression dampening in the design as the bags resistance to compression hits is progressive.
It's a system and everything feeds into it.
If you install them you will find they are somewhat firm. Rolling roads they work well.
Sharp edges and higher pressure tires you will notice more.
Can be turned down but then the body roll was more noticeable.
Are they worn? Surely. 100k miles.
My experience with these and multiple owners was one quarter turn more dampening per 50k miles.
They are at 3 now I think.
If I did not have to drive LA freeways I would have left them on.
Tires and FSD's were over $6k plus the intermediate adjustment costs as I had a shop do them
There is a rebound chart for redtops around. I could not find it quickly
Just changed to Koni (gold) shocks and have driven 2500 miles on them (to Nag and back). A vastly improved ride over my supposedly fully functional Bilstein shocks.
Had a slight wander to the right when driving, was running on the rumble strips all the time, joints in the concrete roads were noisy and rough.
Got 8 Koni Shock Absorber Warehouse for under $1200.
Plan in changing my shocks too to Koni asap. My shocks are original and while they probably could be adjusted, would rather just go with new ones. Hope that and steering box rebuild will improve the ride a bit for the next 10 years.
Thanks for the input. I have installed the reds on the front, and it is definitely an improvement. I just want to ascertain whether or not the shocks are working right before putting in the significant effort involved in installing the rears and tuning them all. They all seem the same, and no signs of leakage. My thinking was that compression damping would not be needed, that being supplied by the air springs. It appears I'm wrong about this, and im probably better served by replacing with new. Just for grins will probably see if I can reach a Koni tech, see if they have any tips. Appreciate the help.
Chuck,
Actually, what I would do is set them toward the firm side and drive it. THEN determine which direction to go. I know the custom Konis I had built were more than 10X dampening on extension than on compression. May be difficult to tell no resistance from 1/10 dampening.
The objective is the smoothest ride with less than 1.5 bounces over the large ones.
Well now, there's food for thought. I'm thinking I can easily measure extension/retraction times but thinking back the compression probably takes a second using body weight and rebound maybe 15 seconds using arm force. Unfortunately arm force is substantially less than body weight so it sounds like I'm in the ballpark.
Lest anyone think I'm a cheap bas...., err "Frugal", I regard repair and reuse of machinery as a higher order of recycling and a personal mechanical challenge. Course I guess we all do, that's why we drive 20 year old motorhomes!
Thanks Brett!
Put the backs on. Enjoy
My front axle tends to porpoise on overpasses where the road surface sags between supports. The only way to stop the porpoising is to quickly drop speed My gold Konis don't appear to have an external oil leak yet. Do you think replacement will solve my problem?
Dave Reed
Dave,
Not sure we can do anything more than speculate as to whether the shocks on your coach are OK or worn.
You might contact Koni: KONI NA | Motorhome (http://www.koni-na.com/en-US/NorthAmerica/Products/Motorhome/)
Before buying more new ones, a viable option would be to arrange with Koni to send them back (they are in Hebron, KY) for testing.
My Koni rv gold shocks are lifetime warrantied. You might ask Koni.
Brett,
Thank you for your suggestion; I'll contact Koni to get their thoughts for a solution.
Bob,
Yes, Koni has a lifetime limited warranty.
Our best to the two of you for sharing your information with us
Dave & Cynthia
Life time warranty for replacement shocks.
Limited warranty for OE-- I suspect manufacturers get a price break for this, but that is just speculation.