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dadmomh's avatar
dadmomh
Explorer
May 07, 2013

Tongue Weight calculating

Help! As much as I never thought we'd say it, we're looking to move to the dark side with a Rockwood Ultra Lite 2604. We're doing our homework and trying to figure the tongue weight. DH got the info from the dealer with our VIN, but they didn't have tongue weight. Our F-150 Crew Cab is rated at 8000+ - actually they said 8300, but he's sticking with 8000. GCVWR is 13,000+. It's a 5.4 with a 5.31 (?) rear end....he already put the book away and doesn't want to go and drag it back out, so please don't fuss if he has his numbers transposed or other. We'll be keeping the Equalizer set up. The tongue weight is 739# on the 2604. The GVWR is 6629. I already know that IF and when the time comes, I need to unload a few things....anybody want a Cuisnart Ice Cream Freezer??? How 'bout some other cr.. that we find?? I needed to do this anyway just for ease of getting around. I already unloaded the DO.. Our 23SS is at 5000# on the nose ready to pull out, so I know we won't get to the GVWR, but need to know how to figure the tongue weight.

We/I really, really want to make this change. As much as we LOVE our ROO, age and ability is getting in the way. But, at the same time, don't want to be stupid and have a bad combo. If this works out, there will be a mint condition 23SS on the market with all sorts of little extras thrown in. Help!!!

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  • Francesca_Knowl's avatar
    Francesca_Knowl
    Explorer
    May 07, 2013
    dadmomh wrote:
    Help! As much as I never thought we'd say it, we're looking to move to the dark side with a Rockwood Ultra Lite 2604. We're doing our homework and trying to figure the tongue weight. DH got the info from the dealer with our VIN, but they didn't have tongue weight. Our F-150 Crew Cab is rated at 8000+ - actually they said 8300, but he's sticking with 8000. GCVWR is 13,000+. It's a 5.4 with a 5.31 (?) rear end ....he already put the book away and doesn't want to go and drag it back out, so please don't fuss if he has his numbers transposed or other. We'll be keeping the Equalizer set up. The tongue weight is 739# on the 2604. The GVWR is 6629. I already know that IF and when the time comes, I need to unload a few things....anybody want a Cuisnart Ice Cream Freezer??? How 'bout some other cr.. that we find?? I needed to do this anyway just for ease of getting around. I already unloaded the DO.. Our 23SS is at 5000# on the nose ready to pull out, so I know we won't get to the GVWR, but need to know how to figure the tongue weight.

    We/I really, really want to make this change. As much as we LOVE our ROO, age and ability is getting in the way. But, at the same time, don't want to be stupid and have a bad combo. If this works out, there will be a mint condition 23SS on the market with all sorts of little extras thrown in. Help!!!


    It 's always surprising to me how much some so-called "Ultralight" trailers weigh!

    You don't say what model year 2604 you're looking at, but the 2012 model specs at this link lists gross weight as 6603 pounds, curb as about 5500. The same link gives dry hitch as 603 pounds- that will increase if you add propane tanks, etc. Since optimum tongue weight is considered to be around ten percent of total, I recommend using about 650 pounds of tongue as a planning number for that trailer.

    Per your truck's capacity:

    Looking at the specs at this Ford link...I don't see a "5.31" rear end...could it be a 3.31 rear axle? That would match up with the 13,000 pound GCWR.

    There are some differences in payload given for "crew cab" configurations at that link, but it looks like you have at least 1800 pounds of payload, which is the number from which you must deduct hitch weight. 650 lbs. on the tongue would leave you with well over a thousand pounds for passengers, fuel, cargo, etc, at least in the truck. That seems more than sufficient...and since the trailer itself is well under the recommended tow limit of 8,000 pounds plus, it seems to me that the whole combination should work just fine.
  • dadmomh's avatar
    dadmomh
    Explorer
    May 07, 2013
    Nope, maybe I'm totally messing up this question - it's happened before. I went and retrieved the manual and it's a 5.4 engine with a 3.55 rear end. Rated for 8300# trailer. So quess my queston is.....will a trailer with the # shown above and a tongue weight of 739# be good. Actually, the link to the 2604 above is not to the one we're looking at. That one is the 2604WS which has a huge wardrobe in the bedroom area that is a second slide. We're looking at the 2604 with only the dinette/sofa slide. We don't need or want that much extra space or weight. Reminder that we are using the Equalizer with sway and Prodigy just as we have now. Please don't let us make a huge mistake here. Chuck and Dan.....where are you?????
  • Brian_B1's avatar
    Brian_B1
    Explorer
    May 07, 2013
    No street truck has that low of gears (numerically higher). Those would be for rock crawling or something.

    4.10 is as low as I have ever seen a stock ford. 3.55 is a lot more common on the F-150. I have seen a few with 3.73 though.


    I wish I could help with your question, but I am new as far as towing goes.
  • dadmomh's avatar
    dadmomh
    Explorer
    May 07, 2013
    I'm sorry, I didn't make that very clear....possibly because these calculations are not in my job description. What I need to know is with those engine/rear end numbers and with the numbers on the 2604, will we be in safe range with this combo. Did that make any better sense....I doubt it, but hope somebody can help us. Somehow I seem to remember (??) that the tongue weight should be x% of the GVWR or maybe not. Like I said, not in my job description. DH cannot find this in the owners manual and the Ford dealer thought it sounded fine, but wasn't sure. Not a close enough answer. Maybe I need to go out and retrieve the owners manual to double check the info. UGH! Maybe we should just keep the ROO - gonna cry if it leaves.
  • the_bear_II's avatar
    the_bear_II
    Explorer
    May 07, 2013
    You can take two bathroom scales and place them under the tongue jack with a 4X4 board between tthe scales. Lower the tongue jack onto the the 4X4 and read the scales, add the amounts together to get your tongue weight. Be sure to subtract the weight of the 4X4.

    Keep in mind you'll need scales with 400 pound capacity and the result you get may not be 100% accurate.

    The dealer or the manufacturer will have the tongue weight.

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