2008 Monaco Cayman Rear Swing Arms

[Cj D]

I guess I missed this class along the way.

We bought our coach new in 2008 and have 66k miles on it. During our latest trip the left rear swing arm broke in two. I do all my own work on the coach (especially since Monaco treats us like lepers since the bankruptcy), so I figured I'd search the web for a used trailing arm to install...only to learn the drama that has been going on since before we bought our coach!

So, the current way to go is to use the Source Engineering arms out of Portland. I find they are a month behind in making the arms, then they have to be shipped via semi for at least another 2 weeks. A bit long during the summer season.

Anyway, can you guys fill me in on the latest with this issue. The previous threads are extensive, but seem to end about 8 years ago. Has anything happened since that time?

[153stars]

I read Rev started making them too bad POs didn't get them done under recall.

[Mile Marker 42]

Originally Posted by Cj D

I guess I missed this class along the way.

We bought our coach new in 2008 and have 66k miles on it. During our latest trip the left rear swing arm broke in two. I do all my own work on the coach (especially since Monaco treats us like lepers since the bankruptcy), so I figured I'd search the web for a used trailing arm to install...only to learn the drama that has been going on since before we bought our coach!

So, the current way to go is to use the Source Engineering arms out of Portland. I find they are a month behind in making the arms, then they have to be shipped via semi for at least another 2 weeks. A bit long during the summer season.

Anyway, can you guys fill me in on the latest with this issue. The previous threads are extensive, but seem to end about 8 years ago. Has anything happened since that time?

Call 1 of Source's dealers as they may have it in stock?

[Cj D]

From what I understand, the initial problem occurred on the 2002 to 2006 models. Those were recalled and the trailing arms were replaced under warranty with beefed up factory arms, which were also installed as original equipment on the 2007 thru 2009 models. These recall replacement arms only lived a few thousand miles longer than the original arms.

SO...nobody were given good arms under warranty, as all the arms fitted prior to the bankruptcy are defective!! I've got no hard feelings, with the exception that the DOT should have forwarded the recall to us. We are the original owners, so it's not like we are hard to find.

The breakage of the arm was frightening as hell! It happened, as it seems to always be the case, during a panic stop when the freeway went from 75 speed limit to unpredicted full stop...in the rain no less. When the arm fractured the rear of the coach moved at least a foot to the right, forcing me to counter steer to the right to hold the lane, while the ATC and ABS were both flashing like crazy. I was lucky to get it stopped. When I released the brakes, everything seemed to go back to normal, at least until any time the brakes were used. We were driving in torrential rain, so I convinced myself one of the brake drums was water logged. What was happening is that every time the brakes pulled on the axle, the right side of the axle pulled back, causing the coach to track sideways. When the brakes were released, the axle moved forward until it hit the broken stub of the trailing arm, which brought it almost into alignment. When not braking the only symptom was that the steering wheel was a few degrees from centered.

The truly frightening part is thinking about the mechanics of the failure. The load from the broken arm is transferred to the opposite trailing arm. The left arm is all that was holding the axle in the coach. If that arm had failed to, the rear axle would be completely unsecured and free to roll out from under the coach! For a part this important, the recall should have been forwarded to all owners...no excuses.

I priced building my own arms, and it was going to cost over $2k in steel alone, so I went ahead and ordered the Source Engineering arms. $2695 with shipping. Ouch. I limped the coach to the barn at 30mph and will wait for the new trailing arms to arrive.

I have to ask, are there any more safety items for the 2008 model year coaches that I missed?

[Mit12]

I have a 2008 Diplomat, I assume that my coach has the same suspension as your coach? Can you post a picture of the broken arm? I would like to keep an eye on mine.

[Cj D]

Actually, you have the RR8R chassis, so it has a different suspension.

[skinr1]

Did you receive your new arms yet? I ordered last week $2545 to my door. Jim with Source told me two weeks but I think that might have been to make me feel good.

[Cj D]

Not yet. He told me 3 weeks and that will be Tuesday...so I will check with him then.

I have been looking at his "ride improvement package" and drooling over it. I want to order it, but it runs $2,400, and I'm already forking over a lot for the arms. Maybe next year?!?

[johnfr80504]

Originally Posted by Cj D

I have been looking at his "ride improvement package" and drooling over it. I want to order it, but it runs $2,400, and I'm already forking over a lot for the arms.

The "ride improvement package" may have saved our marriage. Best money I have spent on our rig. Before we put it on the suspension would bottom out every time we went onto a bridge, overpass or hit a pot hole. Would totally freak out my wife.

We purchased our 2007 Cayman used "As Is" with 4024 miles on it in 2019. A couple days after we got it home, I learned about the trailing arm issue. Knowing we wanted to use our coach for many years I decided to replace the trailing arms for our peace of mind and safety. I contacted Source Engineering about purchasing them and having them installed locally in the Denver area. No shop in the area was willing to do it for less than $3600 labor. Many wouldn't even consider working on it because it was over 10 years old.

We op'ed to make our first trip to be to Oregon to have Source Engineering do the install. They quoted us $980 to do the install. I discussed the "ride improvement package" with Jim at Source Engineering and he offered to install it at no extra cost if we did it at the same time as we did the trailing arms. The whole job took them about 6 hours. After they finished we pulled away from their shop and I could tell within 10 miles that the added expense for the "ride improvement package"was going to be worth every penny.

[Cj D]

I was afraid of that! Thanks for the review, John, you're making it harder not to justify getting the ride package. And it does make sense to install it "while we're there"! We have over 60k miles on the rig, but from day one I always thought the shocks could be a lot better. And now that she's 13 years old, I think it wise to replace the air bags before they start going.

Guess I'll give Source a call and budget in the ride package...

[Cj D]

Well, ordered the ride enhancement package. I'll give a review when I go to install all these high dollar components...

[Ktaylorr1]

We just purchased a 2008 with 30k and was surprised at how badly it bottoms out while crossing bridges. It does have the SE trailing arms, I made sure of that, but think I will change the front bags in the near future.

[Cj D]

The way Jim at SE explains it is that, first of all, Monaco used the same air bags on the smaller frames that they did on the large chassis. The result is a very firm ride to start with. Then, the OEM shocks are only single valved, so they provide no restriction on the bounce, but only on the rebound. The result is that if you are on a particularly bumpy stretch of road, the suspension jacks downward...which also increases the harsh ride until it has a chance to recover.

The kit uses shocks that are double valved, so they restrict to a lesser amount, but in both directions, so there is less tendency to jack up or down over bumps. Then, the bags are smaller, allowing the suspension to use more travel...reducing the ride harshness. And finally, there is an extra "can" to add even more volume to the bags, also allowing more travel on the suspension.

That's the idea, anyway. Over our 60k miles, we have been on roads where my wife would have bounced off the ceiling if she were not strapped in. I am hoping this kit will improve the ride. I'll let everyone know how it goes!

I am still going through the stages of grief after having these trailing arms break on us. SOMEBODY at the USDOT or Monaco should inform all owners, regardless of the bankruptcy or not. This is a serious failure that owners need to be told about.

[Cj D]

It's been 4 weeks since I ordered the arms. Checked with Ann at Roadmaster and she says the bushings are back ordered. Hopefully shipping next week...but she didn't sound confident about that. Meanwhile the ride enhancement kit is being held up by backordered shocks.

Gotta love Covid.