Can't help but dive in on this subject. I did a considerable amount of research into this subject before buying a motorhome due to it's intended use. I hope this experience helps you.
I have a 2000 four winds 22RK that was built by thor with an E-450 chassis, not the standard for model E-350. We did this specifically for pulling a trailer, which weighs 9500 lbs. The main differences between the two chassis is added section height in the 450 frame rails, and the use of the Dana M80HD rear axle assy (4.63 ratio) on the 450 chassis, which has a much higher GAWR (gross axle weight rating, it's ability to carry weight) than that of the 350 chassis, which is a Dana M70. The typical ratio in the M70 is 4.11 in an E-350, however, the 4.56 may be an option. The 450 chassis is indeed rated in this arrangement at 20,000 GCW.
The 22RK has only a 6 ft overhang behind the rear wheels, which, as built by thor, uses the factory frame rails all the way to the rear bumper. The hitch thus attaches to the Ford factory mounting holes, of which either a 5000 or 10,000 lb hitches are available. The critical factor here is the extension of the frame on your vehicle, as the ford rails are about 8" in height, and it is sometimes common for Motorhome manufactures to use only 4" high channel steel to support the rear of the vehicle, leaving a frame with less strength to support a load bearing trailer hitch.
We have more than 50,000 miles of trouble free towing with this vehicle, some of it cross country. I would not think that the Ford frame, rear axle assembly, or driveline as produced would be an issue for flat towing a passenger car behind it, based on our experience, assuming you do not exceed the 20,000 lb rating. The issue, I believe for you, is the strength of the frame extension built by your motorhome manufacturer to support the hitch.
If you wish to compare frame design, the E-450 rear frame section is the same as an F-450 truck. You can see it at your local Ford Dealer, and compare it with your motorhome.
Quote: ...But things don't always appear to be what they actually are. It seems that Holiday Rambler, for whatever reason(s), ordered E-450 chassis from Ford that had 4.56:1 rear axle ratio, not 4.63:1 EVEN THOUGH EVERY PIECE OF PRINT MATERIAL FROM FORD STATES THAT THE 4.63:1 REAR AXLE IS STANDARD EQUIPMENT. This rear axle has a GCWR of 17,550# thus limiting the towing to 3,500#...
Well, I've confirmed that I have the 4.56 axle as well - quite a surprise, as that is not even listed in the owner's manual.
The 6.8L/4.10 rear end is rated at 18,500 lbs GCWR for the E-350 cutaway and the 6.8L/4.63 rear end is rated at 20,000 lbs GCWR, leaving me to wonder what the 6.8L/4.56 rear end rating might really be. You say 17,550, but where are you getting that information?
I sure would like to know!!
* This post was
edited 11/02/04 11:10pm by Westronics *
Hi all...I've not been looking at this for a few weeks now. I had a chance to speak with the person that supervises engineering and design at Monaco (parent company of Holiday Rambler).
Let me restate what has happened: The documentation I received from Holiday Rambler included a brochure from Ford that gave specifications of the E450 chassis. This documentation clearly states that ALL (used with caution) cutaway E450 chassis use the 4.63:1 rear axle. Holiday Rambler basically told Ford to substitute this rear axle with the 4.56:1 rear axle. The reason for this is not clear. Maybe it was a cost saving excuse. I confirmed this by crawling under the MH and looking at the tag on the differential which describes the axle as having a 4.56:1 ratio. How does this effect things? There is a sticker on my bathroom medicine cabinet door that gives all the weights (GVWR, CCC, etc.). According to this sticker I have a towing capacity of 5,500 pounds. To make the story short, HR listed specifications that apply IF the 4.63 axle was installed. HR never adjusted the numbers to conform to the installation of the 4.56 axle!!
What does this mean? I took the time to contact HR about my concerns. But what if I someone else looked at the numbers and never questioned HR? Some poor soul could have easily swapped out their 3,500 pound hitch for a 5,000 pound hitch based on the specifications listed by HR, NOT KNOWING THAT THEY ARE ACTUALLY EXCEEDING THE RATED TOWING CAPACITY!!!!!!
In my conversation with the rep at HR I tried to explain that the numbers are misleading. His answer was that the 3,500 pound hitch is installed for safety reasons. Never did he acknowledge that there is a safety concern because of incorrect specifications. I now plan to notify the NHTSA that a potentially unsafe situation exists with this model motorhome. What I expect to get out of this is quite different than what will probably happen: I want HR to install the axle that Ford has stated should be standard equipment on my chassis (4.63:1). What will probably happen is HR will have dealers place a new sticker showing the correct specifications over the old sticker.
[quote]... This documentation clearly states that ALL (used with caution) cutaway E450 chassis use the 4.63:1 rear axle. Holiday Rambler basically told Ford to substitute this rear axle with the 4.56:1 rear axle...[/quote]
As near as I can tell, the 4.56 is standard in Canada (see: [url=https://www.fleet.ford.ca/english/products_services/specialty_vehicles/specsClassC.asp]Canadian Specs[/url]]), but it is rated for the [b]SAME[/b] GCWR as the 4.63, 20,000 lbs, though with a 5,950-lb towing limit. While this is true, the Ford towing guide lists the GCWR for the 4.56 rear end as 18,500, with a 10,000-lb towing limit, though this is for an E-350, not an E-450 as this combination (E-450/6.8L/4.56 gears) is not listed in the towing guide.
Leaving me once again (or still) to wonder just what is happening here and what true reasons there are for lowering the GCWR from the listed 20,000 to something less - typically either 17,550 or 19,050, both of which are simply the GVWR plus 3,500 or plus 5,000.
It has become rather apparent that it is impossible to get a truly straight answer from MH manufacturers. Every answer I've seen to date, including those I personally got from Jayco, has actual, verifiable factual errors in it.
So here's we KNOW or have from CONJECTURE:
1. Ford has made no significant design changes from the introduction of the E-450 that affect the GCWR. I feel comfortable stating this as a known fact.
2. The cutaway E-450 chassis comes with a 4.63 rear end in the U.S. and a 4.56 rear end in Canada, though it's GCWR is the same. I feel comfortable stating this also as a known fact, since we have direct evidence from Ford for this.
3. The MH cutaway chassis typically (always?) has a different wheelbase from that offered standard by Ford AND has a 4.56 rear end. I do not know how common the 4.56 rear end is for motorhomes, but the Ford towing guide does list a reduced GCWR of 18,500 for the 4.56 rear axle, but that for teh E-350, it is not listed as avaiable for teh E-450 and teh Canada site lists the E450 with the 4.56 as having a GCWR of 20,000 lbs.
4. Models from a couple of years ago had 3,500-lb hitches, and current models have 5,000-lb hitches with no apparent design changes to the chassis. No satisfactory explanation for this has yet been offered up by any manufacturer, leaving one to wonder if it is okay to do this same sort of hitch swap on an older model.
5. Some MH manufacturers have re-labeled the GCWR to 17,550 for the older models and 19,050 for the newer models, while some have kept the Ford GCWR of 20,000 lbs. You may note that in these cases the GCWR is simply the GVWR plus the hitch rating, leading me to believe that it is not an accurate GCWR.
6. Some frame extensions do not appear to be as strong a the original frame, possibly introducing a weak point that could reduce towing capacity. Some frame extensions appear to be just as strong as the original frame, though.
I don't know what to think. In my case, the frame extension is very short (only about a foot or so) and is the same size as the rest of the frame, welded and bolted to the original frame. The wheelbase is 218", but Ford only offers 138", 158" and 176", so something is odd there, too. The rear axle is a 4.56.
Now I would normally tend to think the MH manufacturer knows what they are doing, but so far my research show NO structural changes between the 2002 and 2005 models of my rig (I even checked with the frame extension manufacturer), and yet the hitch has gotten bigger and the GCWR has gone up. Go figure. I still have not confirmed if the rear axle has changed - that's still a possibility.
It's all very confusing.
I guess we are on our own. My advice for anyone changing the hitch is to be sure and tie it in with the orginal frame, if at all possible. My frame extension is so short I could do this easily, but that's not true for everyone.
Note: Due to invalid formatting, all formatting has been ignored.
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Some of the ideas you touched upon are why I contacted Holiday Rambler in the first place. I noticed that for the 2004 Atlantis Class C, it had a 5,000 pound receiver hitch. The 2004 was built on the E450 chassis. That made me wonder because my 2002 Atlantis, built on a 2001 E450 chassis, had a 3,500 pound receiver hitch. I didn't think that there were any significant changes to the chassis that allowed for the 5,000 pound receiver hitch. In my opinion, the reason HR installed a lower rated hitch on the 2002 model was as a cost saving measure. Since I want to get a tow vehicle that was going to exceed 3,500 pounds I contacted HR to find out if it was possible to change the current hitch for one rated at 5,000 pounds. This is when I entered the "twilight zone" of motorhome manufacturer double speak, lies and inuendos. The rep at HR told me that "revolutionary changes" were being made in the chassis design of the newer vehicles. When I asked what changes were being made from the 2002 model to the 2004 to allow for a hitch rated at 5,00 pounds, he responded with the old "comparing apples to oranges" rhetoric. It wasn't until I told him that I didn't appreciate being spoken down to that he finally admitted that the "revolutionary change" in chassis design was nothing more than the use of the 4.63:1 rear axle instead of the 4.56:1 axle which was used in the 2001 E450 chassis.
Bottom line for me: if I want to replace the hitch I have for a 5,000 pound receiver hitch, I need to make some structural changes in the chassis to reinforce the frame. HR will not stand behind any work I do to modify the chassis. I pity the poor fool wants to change their receiver hitch and uses the weight chart that is posted in the motorhome. The chart is based on the towing capacity using the 4.63:1 axle.
You know, of course, that if your GVW is under 13,500 you could tow 5,000 pounds and not be over the GCWR of 18,500, right? Of course you need a 5,000-pound hitch to do that.
It's also interesting to note that (from the 2002 towing guide) an E-350 cutaway with 6.8L engine and either the 4.10 OR 4.56 rear end is limited to 18,500 pounds of GCW whereas the E-450 with 6.8L and 4.63 rear end is 20,000 pounds GWCR. The difference between 4.10 and 4.56 is much greater than from 4.56 or 4.63, leaving me confused as to what my GCWR truly is (not the bogus rating from Jayco - that's obviously wrong).
I think I'll write Ford and cite the evidence I've found and see what they say.
I called Ford (they have a special division that deals with motorhomes) and they are sending me a different towing guide that include the E-450 and 4.56 rear end.
The actual GCWR of any model year E-450 cutaway chassis with the 4.56 rear end is 20,000 lbs NOT the 18,500 lbs of the E-350 cutaway chassis with the 4.56 rear end. In both instances we are talking about the 6.8L V-10 engine.
edit: I forgot to mention that the I also confirmed that the towing limit is 10,000 pounds, not the 5,950 pound limit quoted in the Ford of Canada link I found.
Further, I received confirmation that no significant structural changes have been made to the E-450 cutaway chassis that would have changed it's GCWR over the years since it's introduction.
Whoo Hoo! This is coming to me IN WRITING from Ford. I'll let you know when I have it.
The only remaining issue is frame strength from frame extensions. I can't help you with that one, unfortunately. In my case it would be nearly trivial to make sure a new hitch was tied in back to the original frame because the frame extension is so short. I don't think that it is needed, though, as the frame extension is attached both by welding AND by a welded bracket that is bolted to the frame.
edit: The best bet is to go to a really good trailer and hitch shop and have them take a look. Have them do the work and make sure they will stand behind it - then you are covered.
The Ford customer support line for motorhomes is 1-800-444-3311. They were very nice, but did ask for my chassis VIN plus my address and phone number before answering any questions. I did not have any issues with that, but thought I'd let you know.
Another edit: Assuming this information is accurate (a good assumption, I think, since Ford is sending it to me in print), then there seems to be some massive misunderstanding of this in the motorhome manufacturing industry, which is less of a surprise than one might think. Having dealt with towing issues before for my trailer, the most commonly misunderstood technical information about a vehicle is its towing information. It seemed clear to me from my brief conversation with Ford that MH manufacturers are not immune from misunderstanding this information.
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Westronics wrote
The actual GCWR of any model year E-450 cutaway chassis with the 4.56 rear end is 20,000 lbs NOT the 18,500 lbs of the E-350 cutaway chassis with the 4.56 rear end. In both instances we are talking about the 6.8L V-10 engine.
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Thanks Westronics, and Shpilkah, for researching this information on Ford E-450 chassis and towing capacities. It appears that you have gone to a great deal of effort to get answers to your questions.
I have a 2004 Holiday Rambler Atlantis 27PDB that I purchased at an RV show in Denver and talked to the Monaco rep. at the show. He said the vehicle had a towing capacity of 5,000 LBS.
During my PDI, I noticed that the towing hitch was rated at 3,500 LBS. I called the Monaco rep. and he said there was some mistake with that low of a towing-capacity hitch being on the vehicle, and he instructed the local dealer to install a 5,000 LBS hitch, which was done.
The sticker in my coach states a GVWR of 14,050 LBS. and a GCWR of 19,050 LBS. I'm already near my GVWR and I'm towing a Jeep TJ that weighs close to 3,500 LBS. However, I may want to tow something heavier in the future.
In the process of the air filter and ABS recall from Ford, I discovered that my 2004 vehicle has a 2003 Ford E-450 chassis.
It sounds like you guys don't have a lot of confidence in the GVWR & GCWR stickers from the manufacturers, so my question is: How do I verify what my GCWR actually is? Do I need to inspect the rear-end housing to determine which rear end (4:56 or 4:63) I have and then refer to a chart? If so, where on the housing is the rear-end ratio stamped?
Or are you saying that all Ford E-450 chassis that were manufactured after 2002 have a GCWR of at least 19,050? Actually, I'd really like to know what exactly the GCWR of my vehicle is (19,050, or 20,000 or what?).
Thanks in advance,
Chris
2004 Holiday Rambler Atlantis 27 PBD
1998 Jeep Wrangler (toad)
1997 Yamaha V-Max (for passing RVs in the Colorado canyons)
Blue Ox Aventa II towbar & Brake Buddy
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