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Old 03-03-2021, 06:38 PM   #1
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Brand: Thor Motor Coach
Model: 28z
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C Class receiver

I have a Thor 28z and am wanting to tow a vehicle which weighs 6000 lbs. My receiver is rated at 5,000 lbs. Is this rating because of the vehicle or the receiver and is there anything that can be done to safely increase the amount?

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Old 03-03-2021, 06:55 PM   #2
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Model: Tiffin Wayfarer 24 BW
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I'll preface my comments; by first stating that I'm an "insurance guy".
I've seen just how bad things can go wrong...
That 5000 pound rating has been put there for several pretty good reasons:
1. the hitch itself perhaps can't survive more than that.
2. the mounting system may not survive more than that.
3. your RV's frame might not survive more than that
4. your RV's braking system and chassis dynamics may not survive more than that.
5. your cargo carrying capacity might not "permit" even that much weight
As an example: my RV has a 5000 pound rated hitch also; yet I can only tow about 4200 pounds before I'm exceeding GVWR limits.
So my setup is weghing in at just over 3000 pounds.
(I don't like to stretch the limits... )

But you do what you have to do: it's your rig!
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Old 03-03-2021, 07:04 PM   #3
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Brand: Thor Motor Coach
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THOR #7401
Quote:
Originally Posted by Bob Denman View Post
I'll preface my comments; by first stating that I'm an "insurance guy".
I've seen just how bad things can go wrong...
That 5000 pound rating has been put there for several pretty good reasons:
1. the hitch itself perhaps can't survive more than that.
2. the mounting system may not survive more than that.
3. your RV's frame might not survive more than that
4. your RV's braking system and chassis dynamics may not survive more than that.
5. your cargo carrying capacity might not "permit" even that much weight
As an example: my RV has a 5000 pound rated hitch also; yet I can only tow about 4200 pounds before I'm exceeding GVWR limits.
So my setup is weghing in at just over 3000 pounds.
(I don't like to stretch the limits... )

But you do what you have to do: it's your rig!
Thanks for the reply. However, I'm looking for facts concerning whether I could simply install a 7500# receiver or what needs to be done to allow a little higher capacity.
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Old 03-03-2021, 07:51 PM   #4
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Originally Posted by Gary A View Post
Thanks for the reply. However, I'm looking for facts concerning whether I could simply install a 7500# receiver or what needs to be done to allow a little higher capacity.
Consult a professional welding shop.
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Old 03-03-2021, 07:53 PM   #5
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Quote:
Originally Posted by Gary A View Post
I have a Thor 28z and am wanting to tow a vehicle which weighs 6000 lbs. My receiver is rated at 5,000 lbs. Is this rating because of the vehicle or the receiver and is there anything that can be done to safely increase the amount?
That rating is for the receiver. You can almost certainly have someone put on a 7500 lbs receiver, but that doesn't mean you can tow 7500 lbs (or 6000).

If you're flat towing:
Look up the GCWR in your chassis owner's manual. Load up as you do for a trip, with all people and cargo, and go weigh your RV. Subtract the weight from the GCWR to see what you have left over - that's the maximum that you can safely flat tow. (It's a good idea to leave some margin.)

If you're dolly or trailer towing:
Do the above, to get the MAXIMUM you could tow. Then, get the axle weights, especially the rear axle. The dolly or trailer tongue weight will add to the rear axle weight. On your door sticker or in the owner's manual, there should be a maximum allowable weight for the rear axle. Subtract the current weight from that number to get how much you can add to the rear axle before going over - that's your maximum allowable tongue weight. (As above, it's a good idea to leave some margin.) You would then need to know how much tongue weight your dolly/trailer is going to add. That should be somewhere in the 11-15% range (660lbs-900lbs) for a trailer - not sure for a dolly. Whatever that number is for you, add it to your current axle weight to see if you would go over. (Amazon sells tongue scales. I should really use mine to weigh my dolly tongue ...)

As a note:
The weight limits that are legally enforceable are the axle weight limits and tire weight limits. GVWR and GCWR are manufacturer recommendations, but generally speaking, they're ones we should all follow for safety.
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Old 03-04-2021, 06:17 PM   #6
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Brand: Thor Motor Coach
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Quote:
Originally Posted by atreis View Post
That rating is for the receiver. You can almost certainly have someone put on a 7500 lbs receiver, but that doesn't mean you can tow 7500 lbs (or 6000).

If you're flat towing:
Look up the GCWR in your chassis owner's manual. Load up as you do for a trip, with all people and cargo, and go weigh your RV. Subtract the weight from the GCWR to see what you have left over - that's the maximum that you can safely flat tow. (It's a good idea to leave some margin.)

If you're dolly or trailer towing:
Do the above, to get the MAXIMUM you could tow. Then, get the axle weights, especially the rear axle. The dolly or trailer tongue weight will add to the rear axle weight. On your door sticker or in the owner's manual, there should be a maximum allowable weight for the rear axle. Subtract the current weight from that number to get how much you can add to the rear axle before going over - that's your maximum allowable tongue weight. (As above, it's a good idea to leave some margin.) You would then need to know how much tongue weight your dolly/trailer is going to add. That should be somewhere in the 11-15% range (660lbs-900lbs) for a trailer - not sure for a dolly. Whatever that number is for you, add it to your current axle weight to see if you would go over. (Amazon sells tongue scales. I should really use mine to weigh my dolly tongue ...)

As a note:
The weight limits that are legally enforceable are the axle weight limits and tire weight limits. GVWR and GCWR are manufacturer recommendations, but generally speaking, they're ones we should all follow for safety.
Thank you.
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