Koni shocks

[Avies48]

Originally Posted by rffowler55

Our Bilstein shocks were starting to be less responsive to rough roads after over 50,000 miles of use so we ordered Koni shocks for the rear but Koni shocks were not available for the front until a projected mid-July date. I went with Bilstein's again on the front since we needed to replace before our next trip. We decided to try the Koni's because of all of the favorable comments on this site but the Bilstein's performed well until the past couple trips. Would have stayed with Bilstein but was curious if the Koni shocks would live up to expectations.

We have 17k on ours and its like going over ridged roads every time we hit a bump with bilteins in, they suck, never had any bilsteins suck this bad and ive had them on trucks and cars a lot

[DirtRider]

Originally Posted by Taffeys

The first thing I did to our E450 was install Koni FSDs, Hellwig sway bars, and a Bilstein steering stabilizer. That plus an alignment made a world of difference in the ride and handling. But what a chore removing and installing the front shocks.

Our RV's are probably fairly similar on weight and weight distribution. Don't you find that the rear axle rides brutally rough? Most people are so used to a class C being way overweight that I don't think they understand how rough the ride can be with an underloaded rear axle.

[Ron Dittmer]

Originally Posted by rffowler55

Our Bilstein shocks were starting to be less responsive to rough roads after over 50,000 miles of use so we ordered Koni shocks for the rear but Koni shocks were not available for the front until a projected mid-July date. I went with Bilstein's again on the front since we needed to replace before our next trip. We decided to try the Koni's because of all of the favorable comments on this site but the Bilstein's performed well until the past couple trips. Would have stayed with Bilstein but was curious if the Koni shocks would live up to expectations.

Did you exercise the lifetime warranty on your Bilstein shocks? I never had a need to yet, just wondering how that works.

[Ron Dittmer]

Originally Posted by DirtRider

Our RV's are probably fairly similar on weight and weight distribution. Don't you find that the rear axle rides brutally rough? Most people are so used to a class C being way overweight that I don't think they understand how rough the ride can be with an underloaded rear axle.

Yes, too much weight margin = rough ride. For the smoothest ride, you want to be close to the axle limit.

Have you considered removing one (or two) rear leaf springs on each rear corner to soften your ride? I did something equivalent for the front of our 24 foot E350. The front coil springs were the same as an E450. My actual front load is 3260 with us sitting in the front seats giving us 1340 pounds of front axle margin. I replaced them with the next lowest rated spring. CLICK HERE for the details with "before and after" pictures.

[Phil G.]

Originally Posted by DirtRider

Our RV's are probably fairly similar on weight and weight distribution. Don't you find that the rear axle rides brutally rough? Most people are so used to a class C being way overweight that I don't think they understand how rough the ride can be with an underloaded rear axle.

Right on the money ... you nailed it!

What the Koni FSD shocks do is A) provide a lot of needed damping ("stiffness") added to the springs' support on slower movements - such as during side-to-side coach leaning on curvers and during the pushes from high crosswinds, and B) provide little to no damping added to the springs' support on fast movements (jolts) from cracks and potholes.

The jolts from cracks and potholes is probabaly going to be most noticeable (and irritating) the less coach weight that the springs are supporting. Hence the Koni FSD shocks remove much of the roughness feeling on small motorhome coaches relative to the weight ratings of their chassis - versus those same chassis models that may also be carrying heavier coach structures.

I have somewhat quantitative proof of what the FSD shocks do in the rear of our 24 ft. Class C on a Ford E450 chassis. Our shower latch (the shower is in the rear) always came loose when traveling with the OEM shocks. With the FSD shocks that latch now never comes loose when traveling.

[DirtRider]

Originally Posted by Ron Dittmer

Yes, too much weight margin = rough ride. For the smoothest ride, you want to be close to the axle limit.

Have you considered removing one (or two) rear leaf springs on each rear corner to soften your ride? I did something equivalent for the front of our 24 foot E350. The front coil springs were the same as an E450. My actual front load is 3260 with us sitting in the front seats giving us 1340 pounds of front axle margin. I replaced them with the next lowest rated spring. CLICK HERE for the details with "before and after" pictures.

Ron, I’ve read your stuff again and again about what you did with the front axle. I think you’re right on the money. On the rear, I’ve definitely wondered about pulling out a leaf. My full thought is going to an E350 leaf, and making up the overage with an adjustable air helper spring. That way I can kind of adjust for the trailer tongue weight I apply. I haven’t found where other people have done this. But more strangely, I haven’t found where Ford has a different part number for an E350 vs E450 leaf pack. I’m sure they do, and I just need to find the right person to discuss it with. But it hasn’t been obvious on google searches.

[Taffeys]

Originally Posted by DirtRider

Our RV's are probably fairly similar on weight and weight distribution. Don't you find that the rear axle rides brutally rough?

No I don't.

[Taffeys]

Originally Posted by Phil G.

Right on the money ... you nailed it!

What the Koni FSD shocks do is A) provide a lot of needed damping ("stiffness") added to the springs' support on slower movements - such as during side-to-side coach leaning on curvers and during the pushes from high crosswinds, and B) provide little to no damping added to the springs' support on fast movements (jolts) from cracks and potholes.

The jolts from cracks and potholes is probabaly going to be most noticeable (and irritating) the less coach weight that the springs are supporting. Hence the Koni FSD shocks remove much of the roughness feeling on small motorhome coaches relative to the weight ratings of their chassis - versus those same chassis models that may also be carrying heavier coach structures.

I have somewhat quantitative proof of what the FSD shocks do in the rear of our 24 ft. Class C on a Ford E450 chassis. Our shower latch (the shower is in the rear) always came loose when traveling with the OEM shocks. With the FSD shocks that latch now never comes loose when traveling.

[Ron Dittmer]

Originally Posted by DirtRider

Ron, I’ve read your stuff again and again about what you did with the front axle. I think you’re right on the money. On the rear, I’ve definitely wondered about pulling out a leaf. My full thought is going to an E350 leaf, and making up the overage with an adjustable air helper spring. That way I can kind of adjust for the trailer tongue weight I apply. I haven’t found where other people have done this. But more strangely, I haven’t found where Ford has a different part number for an E350 vs E450 leaf pack. I’m sure they do, and I just need to find the right person to discuss it with. But it hasn’t been obvious on google searches.

I wonder if simply removing one spring per each stack is easy enough to experiment with, sort of a "trial & error" approach. Do measurements before and after like I did with the front coil springs. Maybe your particular rig's optimized spring pack is somewhere in between an E350 and E450. You might get good pictures of both springs packs on Rockauto.com, count up the stack.

I know my particular rig stands 3" taller when built on an E450 compared to an E350. Some of the extra E450 height is the lack of bending of the leaf springs, and some is likely the dimensional stack itself.

[Avies48]

Originally Posted by DirtRider

Our RV's are probably fairly similar on weight and weight distribution. Don't you find that the rear axle rides brutally rough? Most people are so used to a class C being way overweight that I don't think they understand how rough the ride can be with an underloaded rear axle.

YESSS!! my rear axle is so rough every simgle tiny spec we hit on the road that rear end is like driving on bricks

We have the j ride plus, so maybe i need to adjust the helper springs? Not sure what the last owner had them set to

[rffowler55]

Originally Posted by Ron Dittmer

Did you exercise the lifetime warranty on your Bilstein shocks? I never had a need to yet, just wondering how that works.

Unfortunately the lifetime warranty only applies to the original purchaser of the shocks and we did not qualify or we would have pursued that route.

[DirtRider]

Originally Posted by Taffeys

No I don't.

Interesting! Have you weighed the RV? Maybe Lazy Days puts out a far heavier product than Winnebago? And what's your suspension setup in the rear? I saw the sway bar comment. So, Koni's, sway bar, anything else?

[DirtRider]

Originally Posted by Ron Dittmer

I wonder if simply removing one spring per each stack is easy enough to experiment with, sort of a "trial & error" approach. Do measurements before and after like I did with the front coil springs. Maybe your particular rig's optimized spring pack is somewhere in between an E350 and E450. You might get good pictures of both springs packs on Rockauto.com, count up the stack.

I know my particular rig stands 3" taller when built on an E450 compared to an E350. Some of the extra E450 height is the lack of bending of the leaf springs, and some is likely the dimensional stack itself.

I'm really glad you mentioned Rockauto. They have way more specs listed for their parts than everywhere else I looked. Based upon those specs and the multiple packs they sell, it looks like you get ABOUT 1,000lbs of capacity per inch of pack thickness. So I can go slap a tape on mine and figure out where I'm at in capacity. I expect I need to drop 750lbs of capacity per side or so.

[Ron Dittmer]

Originally Posted by DirtRider

I'm really glad you mentioned Rockauto. They have way more specs listed for their parts than everywhere else I looked. Based upon those specs and the multiple packs they sell, it looks like you get ABOUT 1,000lbs of capacity per inch of pack thickness. So I can go slap a tape on mine and figure out where I'm at in capacity. I expect I need to drop 750lbs of capacity per side or so.

It sounds like you found a good starting point. If you pursue it, I would love to read about your experience.

Our 24 foot 2007 E350 chassis is rated at 11,500 pounds with our actual load on the rear axle weighing in at just over the rear axle load rating of 7800 pounds. I would add one extra rear leaf spring per rear corner to compensate, but the rig has always been well behaved, visually supported most especially since the front lowered a bit when changing to softer front coil springs, and the weight on the rear axle provides a nicely dampened ride in back. I hesitate to mess with the rear spring packs because it has been working quite well all these years.

Someone told me many years ago that all the suspension upgrades we had done when the rig was new, installing heavy duty stabilizer bars & shocks along with a rear trac bar, likely increased the load limit, so in reality, we are likely loaded in back with some amount of margin, though unofficially. Our E350 chassis new from Ford originally lacked a rear stabilizer bar. So adding a rear heavy duty Roadmaster bar where there was previously nothing is quite a chassis enhancement.

I will always wonder if Koni-FSD shocks would have offered something extra over our dampened ride today.