Mistaken purchase

[Goodday2020]

Need advice, new to RV's. I purchased a 2011 Monaco Cayman with the expectation of towing a 6500lb horse trailer. The ratings on the playcard are; front axle 13000, rear axle 18000, gvwr 31000, gcwr 38000. Hitch rating 7000 and 500 tongue. Ccc 4400. All looked good. Once got home, weighed with coach empty, all cabinets empty, no water, no sewage; 10600 front axle, 17460 rear axle. Also found tranny is Allison 2500; rated 33000lb max. Crawled under vehicle, got rear axle model number, more bad news; Spicer 17060s, rated17000lb.

Am I in trouble or should I just ignore and enjoy? I knew power plant was marginal, cummins 340. The coach is beautiful. Kept in pristine condition. Has anyone ever changed rear axle to a more heavy duty axle? I can live with tranny limitations, but does make me wonder how a coach manufacturer could have a gcwr of 38000 and tranny limited to 33000.

[Mich F]

To compound your issues, if that horse trailer weighs 6,500#, the tongue weight is most likely considerably more than 500#.

[momdoc]

Welcome to the forum.

I think you are in deep trouble with that set up as you will be well overweight and under powered for what you want to do. I also assume the trailer wt is empty or is it loaded with horses?

Time to rethink your plan...sorrry

Good luck

[Mr_D]

I think you have a really big problem.

[Goodday2020]

Have load cell, I measured trailer tongue weight with horses and cargo at 480lb. Double axle horse trailer, loading does not seem to affect tongue weight with or without horses it is about 480lb. I guess it is well balanced over the two axles. The wife and I have decided to just tow the horse trailer with our pickup truck and only tow car or motorcycle with RV, both weight much less with almost no tongue weight. I would just like to have margin to be able to load up RV and not exceed rear axle rating. Was thinking about replacement of rear axle with spicer 19060s or 20060s (19k and 20k ratings). I could find used axle at RV used part yard. Anyone know who may be knowledgeable in the replacement?

[153stars]

You would want the same drive ratio as well. Someone supplied me with and old brouchure for my rig my optional 400hp \ 4060 trans had different ratio than 300hp/3060 not sure if that's because of motor power or trans gear drive ratio.

[asuperheat]

Others will disagree but I don't think it would be a problem at all. I had a very similar set up and pulled my 5,700 lb Jeep 35,000 miles from one side of the country to the other without issue. It won't explode if you are 100 lbs over. On long steep grades you my drop to 35 mph but it won over heat if it's serviced and it will do fine everywhere else. Heck the ISB is a great motor and will be pretty efficient and reliable.

Don't let everyone convince you you will die and kill every one on the road because you don't have a big motor and a tag.

The difference in my previous set up and yours is I had a 2100 Allison and 300 hp.

[RVPioneer]

The information that you’ve provided indicates that the rear axle weight is either very near, or slightly above the weight rating of the axle. This is on a coach with no water and very few, if any, personal belongings. You have also indicated that the GVWR provided by the manufacturer exceeds the rating provided by the manufacturer of the transmission by 5000lbs.

If you can make ride height adjustments, it may be possible to shift some weight to the front axle. That won’t change the total weight, it will just open up some capacity on the rear in exchange for less capacity on the front. You have about 3000lbs available, less 500 for the trailer, so 2500lbs. Most likely, once loaded for a trip, the coach will be at or above both axle ratings, GVWR and very near maximum towing capacity.

Will it fall apart after 10 miles? No.
Do people operate overloaded RV’s on a regular basis? Yes.

Only you can decide if you want to travel knowing the coach is overloaded.

[cafeguy]

Check the ride height for sure. If the rear is low even 1/2" you may not see it, but it will effect the weight distribution to the front axle a lot. I have seen as much as 1500lbs weight shift front to rear depending on wheel base at 1/2". As RVPioneer said it wont effect total weight but will help.

Contact Monaco and see if they can give you the ride height settings the coach was built with.

[NevadaNick]

I pulled a crewcab gmc pickup behind a Tiffin 38qra with the 340 and 2500 series Allison. I watched temps which were never a problem. I was over 33k for the motorhome alone and not even sure what the pickup weighed.

[Old Scout]

….always thought the major difference between the 2500 and 3000 Allison was engine torque so not sure max weight is that big a deal....think the bigger issue might be the weight of a "comfortably" loaded coach...here again, not sure the axles are in danger of failing but you do need to get a 4-corner weight when "fully" loaded, then match your tire load rating and tire pressure with the corner weights....so perhaps you are not in as big a problem as you think??????

[richard5933]

Originally Posted by Goodday2020

...Has anyone ever changed rear axle to a more heavy duty axle? I can live with tranny limitations, but does make me wonder how a coach manufacturer could have a gcwr of 38000 and tranny limited to 33000.

What would changing the rear axle accomplish? It won't change the GCWR, and you're not over on the rear axle weight right now.

The only limiting factor seems to be a transmission which is not up to the task of pulling the full GCWR. Rather than change the rear axle, I'd be looking for a good rebuilt transmission that is rated for the 38,000 you were thinking you were getting.

[Spdracr39]

Try it and see how it feels. You can usually tell if it feels overloaded and unsafe.

[NevadaNick]

The transmission can handle it.