Community Forums

thejoneses · 01-23-2019, 01:43 PM

Hello, all.

My husband and I are in the market for a pre-owned diesel pusher. We had a 2007 Fleetwood Discovery 40X for several years and sold it in 2017, thinking that we would start traveling Europe and visiting our overseas child. Instead, we miss the part-time RV lifestyle terribly. So...we are searching for our next--and last--diesel pusher.

Our budget is smaller than previously and we are hoping to make up for that with our own bit of knowledge and tapping into what others can tell us about their experiences. We are currently looking online at a 2008 Monaco Diplomat 40SKQ with 55,000 miles, located at a dealership in Florida. It's a long trip. We live in Virginia and before we go much further, we would appreciate any advice that members of this forum would be willing to share.

On paper, the 2008 Diplomat 40SKQ checks several of our boxes. The floorplan is almost exactly like the Discovery 40X--which we loved. (Front kitchen. Mid-ship TV.) It has a 400HP Cummins versus our previous 330 Cat, and an Allison 6-speed.

It also is on a RR8R chassis. We had a Freightliner and we are concerned because, judging from my search of irv2, this particular chassis has had some problems with "trailing arms" and a rough ride. Can someone help to educate us about this, please?

What else should be we be aware of? Wary of? Are there any potential trouble spots in this DP that the owner should have had fixed back when it was new? And so on. I'm writing this because I'm the retired librarian and family researcher, but my husband will be driving, arranging all the maintenance and repairs, and generally being in charge of whatever we buy.

We don't want to buy any coach without a thorough independent inspection. (We passed on a Newmar in December after an inspection by a reliable third party turned up several hidden issues. We know we dodged a bullet.) But we're not exactly sure how to arrange that if buying from a dealer rather than a private party. Anybody have any ideas?

Thank you so much for any help you are willing to offer. We look forward to chatting with you all.

Charlotte (and Herman) Jones

barmcd · 01-23-2019, 02:16 PM

The bad trailing arms were on the R4R and RR4R chassis. As far as I know there have been no issues with the RR8R chassis. I don't see any reason that shouldn't be a dependable and reliable motor home once it passes inspection.

8.3Oilbuner · 01-23-2019, 04:10 PM

Hi Charlotte & Herman; As Dennis mentioned, the RR8R is a good Roadmaster chassis. Dennis has a Dynasty and I have a Windsor. We both have a side radiator coach where the Diplomat will be a rear radiator coach. Just pointing this out because if you do some of your own maintenance, working on the engine and changing fuel filters is a lot easer. If you want to see what others here have been asking questions about the 2008 Diplomat, in the search box at the top right of this page put in, 2008 Monaco Diplomat. This will show you what owners have asked questions about that year of coach. One thing that comes to my mind, trying to remember, I would get the Cummin's engine serial number to make sure it is not in the group that had, I think, wrist pin problems in the engine. Check this out as some years of the ISL have had a few problems. This is just a suggestion but comes to my mind! Also you probably know that you can go to the Monaco Coach web site and download the brochure and the owners manual for the 2008 Diplomat. Also during the inspection, check the bottom of all the slides to check for water intrusion in the floor of the slides. It has been known that the design of the floor to the outside wall can let water intrude into the floor if the outside bottom flange of the floor has not been kept sealed. Don't let this discourage you if this is a problem as there is a fix for it . I know you are looking at the Diplomat and IMHO I think it is a great coach. I don't know your budget and I know you mentioned the floor plan is what you are looking for. If I was shopping for my final coach, just a suggestion, I would be looking at a Monaco Dynasty. If taken care of, it would be a solid buy for all that comes with that model. I tried to find one in the 34' length after we sold our 2000 32' Windsor. We did the same as you. Sold our coach and missed the adventure. A 34' newer Dynasty is a rare bird and not many made where the Dynasty's are more plentiful in the length you are looking for. I know I am off your subject but I just wanted to put it out there. You know about getting a good inspector so you don't get something with problems. Have fun gathering information and good luck!

vito.a · 01-23-2019, 04:49 PM

This should be a great coach. The RR8R chassis will ride as good or better than your previous Freightliner. Quality will be a few notches higher. A 2008 coach will have a 2007 model engine. The Cummins ISL is a solid performer with performance and reliabilty well above your previous C7 Cat.

The only drawback to this coach is the rear radiator makes it difficult to work on the engine, but your previous coach was a rear radiator also.

Download the original Monaco brochure here:
https://www.monacocoach.com/luxury-rv-brochures?y=2008

If your budget will work, a Monaco Camelot is just above the Diplomat and it will have a side radiator. Above the Camelot is the Windsor, and then the Dynasty.
Best of luck!

RockyMtnRide · 01-23-2019, 07:08 PM

The ISL wrist pin problem was discovered with engines from 2006. Some may have been inventoried for use later. I have a 2006 Diplomat with an engine in the serial number group. I haven’t had any problems and I’m approaching 58,000 miles. I do have my oil tested every season and so far clean. Many say if the engine did have the out of tolerance part the engine would show signs of failure in the first 10,000 miles and according to a Cummins engineer I met at the FMCA rally in Gillette last year very few out of spec parts made it through the system. I personally do not know of a single reported failure.

Ivylog · 01-23-2019, 07:54 PM

Monaco bought up a bunch of extra 06 engines..my 08 has a 06 engine. Like the above post I would think by 50K miles the issue would have shown up so don’t worry about it BUT having talked to a 06 engine owner this past summer whose engine had a big hole in its side at 48,000 miles. Took 4 years and a good lawyer to finally get some help from Cummins on a new engine. Get the engine serial # and make sure it’s # is not in the sticky in the Cummins engine section with the affected serial #s.

Yes the RR8R is a good handling rig IF it has a adjustable TRW steering gear box. It has an adjusting screw on its side locked by a 3/4” jam nut.

RockyMtnRide · 01-23-2019, 08:10 PM

Quote:

Originally Posted by Ivylog

Monaco bought up a bunch of extra 06 engines..my 08 has a 06 engine. Like the above post I would think by 50K miles the issue would have shown up so don’t worry about it BUT having talked to a 06 engine owner this past summer whose engine had a big hole in its side at 48,000 miles. Took 4 years and a good lawyer to finally get some help from Cummins on a new engine. Get the engine serial # and make sure it’s # is not in the sticky in the Cummins engine section with the affected serial #s.

Yes the RR8R is a good handling rig IF it has a adjustable TRW steering gear box. It has an adjusting screw on its side locked by a 3/4” jam nut.

That’s the first report I’ve heard about. Did he mention any warning signs? Increased crankcase pressure, noise, oil consumption, higher temps? Wonder if he ever tested his oil for metals

Ivylog · 01-24-2019, 08:05 AM

Quote:

Originally Posted by RockyMtnRide

That’s the first report I’ve heard about. Did he mention any warning signs? Increased crankcase pressure, noise, oil consumption, higher temps? Wonder if he ever tested his oil for metals

He said there were no warning signs and my understanding of the issue is that the radius of the machining was wrong.
The only way he got Cummins to finally help out some was the Judge told Cummins they had to provide the discovery info on the # of failures.

RockyMtnRide · 01-24-2019, 09:41 AM

Quote:

Originally Posted by Ivylog

He said there were no warning signs and my understanding of the issue is that the radius of the machining was wrong.

The only way he got Cummins to finally help out some was the Judge told Cummins they had to provide the discovery info on the # of failures.

The Cummins engineer at the FMCA Rally said the same thing, that it was a machining error. He said it was off by some absurdly small dimension; like .000001 but that it was a problem. And the really sticky issue is they didn’t know how many actually slipped through QC, thus the wide number of published serial numbers. I’m crossing my fingers I will continue to be OK. So far oil testing has shown no metal residual.