Shocks Broken, Replace with Road King Shocks

[DeltaDonnie]

Just purchased a Country Coach Magna, after review I have two broken shocks on the rear. I have been told by the dealer Road King is a superior replacement to the existing Koni. Apparently Koni is slightly under rated for this coach as they have had some trouble.

Has anyone had positive experience with Road King Shocks?

[wolfe10]

Don,

VERY first thing is to determine what broke the shocks.

The number one cause of a quality shocks (Koni is a quality shock) breaking is incorrect ride height.

If ride height is too high, the shock can be pulled apart on extension-- they are not designed to support the weight of the axle/not designed to act as the travel stop for suspension travel.

If ride height is too low, the shocks can be crushed on compression. Again they are not designed to act as the stop for suspension travel.

Properly speced, shocks will not reach their minimum compressed length on compression and will not reach their maximum extended length on extension.

Improper ride height in the rear also leads to other significant problems. That short drive shaft was designed to run at a certain angle to transmission and certain angle to the rear axle. Raise or lower ride height, and you materially affect drive line angles.

Please let us know what part of the shock broke (pulled apart, crushed, etc) and whether your ride height is to factory spec.

Brett

[DeltaDonnie]

I have taken this coach to a reputible Country Coach Repair Facility in Oregon, very confident they are experts with Country Coach in fact several employees are Ex-employees of Country Coach.

See explanation below from them;

They are broken from over extension which is common on Country Coaches. The ride height is correct and is not the problem. I have no motive to sell Road Kings for any other reason than I know they perform and are guaranteed for the life of the coach. I have a lot of customers who are very happy that I made this recommendation to them when they had similar problems your coach is having.

So for the record, why did the shock break?

Was the ride height adjusted properly? Yes, the ride height is correct.

Did the shock pull apart? Yes, the driver side pulled completely apart and the driver side just broke but didn’t separate.

Did the shock crush on compression? No, it was from over extending. Common problem with these shocks on Country Coaches.

[wolfe10]

Don,

My next move would be to measure static shock length. Said another way, measure pin to pin with coach on flat ground, suspension at proper ride height.

Yours would not be the first time I have heard of incorrect length shocks speced by a chassis/coach manufacturer.

After you measure that and know your Koni shock part number, give Koni a call to discuss whether you have the correct shock for your set-up: Koni Shocks Jim Ryan (859) 488-0339.

I would much rather see you get the proper length shock than look for one that is strong enough to work outside normal shock design specs. No one designs a shock to support the weight of the rear axle on extension.

My definition of the proper length is: doesn't support weight of rear axle on extension and doesn't serve as bump stop on compression.

While you are under there, determine what, if anything serves limit suspension travel on extension. Some air bag suspensions use HD straps from axle to chassis to limit suspension travel on extension.

BTW, I have an older Koni shock book. Let me know the part number and I may be able to tell you the min/max working length of the shocks. That would give you a good starting point when you do your measuring of static length.

And, please don't misunderstand. I am not recommending against Road King or any other shock. But I would like to see you only ask a shock to do what it was designed to do, not that plus act as as the limiter on suspension travel/support the weight of the rear axle.

Brett

[boguslaw]

This is a very interesting thread for me as I was just at a shop having oil changed and a lube job when the Tech noticed I had two broken rear shocks. These are Bilsteins on a 2007Country Coach Tribute. With all the problems with the older units I thought they would have fixed this issue.

It looks like the shocks were pulled apart from over extension, which I guess could be the wrong ride height. You would think they had shocks installed with sufficient travel so they are are not the primary travel limiter. Now I have two new ones, at the tune of $600 which, no doubt the same travel, waiting for it to happen again. should I have the ride height checked? Would that be enough to fix it so I don't break them again?

Jim Boguslaw

[wolfe10]

Jim,

Did you measure the extended length of old and new shocks?

And, yes, checking ride height may be in order.

But, as I stated above, "While you are under there, determine what, if anything serves limit suspension travel on extension. Some air bag suspensions use HD straps from axle to chassis to limit suspension travel on extension."

It may be that CC did not properly limit axle travel on extension, leaving the shocks with a job they were not designed to do.

It should be easy to determine which is the cause of the issues if you go through the steps discussed in this thread.

Brett

[DeltaDonnie]

I spoke with Previous Country Coach Technicians and they do not have a limiting feature on their chassis. It is a common failure which happens on Country Coach. I talked with Road Master (Bill), he stated in a nut shell the Road King Shock is much stronger than other manufactures. The dampening force of 4800 lbs will certainly limit the travel a shock might have, but would may not limit an over extension. He did say most likely their shocks would eliminate the problem because of the force the shock will handle on compression and extension, where other shocks may travel 6 inches theirs may only travel 2 - 3 inches, essentially eliminating an over extension. Country Coach does not have a limiting feature on the chassis to compensate over extension.

[DeltaDonnie]

Brett,

Here are the measurements found on my Coach for the record.

Finally got the chance to creep under there, very difficult to get truly accurate on rear axle's but I'm sure I'm within 1/8".

Front Koni part # 3407 90 2085 center stud to stud 14.750 inches

Rear Drive Koni part # 3407 9044 1004 center stud to stud 15.750 (within 1/8" + or -)

Tag Koni part # 0607 8805 1011 center stud to stud 18.000 inches (within 1/8" + or -

[wolfe10]

Thanks for the update, Don.

As I Private Messaged you, I forwarded your information to my engineering contact at Koni.

Here is his reply:

There's a design flaw in the rear suspension. He must get axle straps. Have him contact Tim at Specialty Logistics (541) 515-6651.

Back to my comments: As I posted earlier, NO shock whether Koni or Road King is designed to act as an axle stop. And even if they don't break, acting as an axle stop would put significant stress on the shock mounts. And they are even harder to repair than broken shocks.

Bottom line, axle straps are the way to go-- far better than pulling apart shocks or breaking shock mounts (both of which I have seen on poorly designed suspensions or coaches with out of spec ride heights).

Brett

[Coach2112]

I've had them for over a year and there's nothing out there that comes close to what these shocks have done for me, the ride is so smooth compare to any other shock out there. I wish I knew about years ago...Did u ever end up buying them?