What is shaking my TM apart as I drive?

[gonzo628]

We are now in our second trip, and it would appear that the Weight Distributing Hitch is beating the tar out of our camper. When I set up, I noticed a bunch of screws are loose (internally and externally). Also, my fridge was about three quarters of an inch out of the cabinet on the right side. I have the Haulmaster WDH. Any ideas?

[Bill]

Whatever it is, it is probably not the WDH. How did you reach that conclusion?

It is almost certainly TM tires out of balance. Tire places will tell you (as they did me) "We never balance trailer tires!" And my response is "Well, I've got the tires, and I've got the wallet. What do you want to do?"

Seriously, it is important to balance them. Another possibility is that your tires are rock-hard. By any chance are you running Load Range D tires, inflated to 65 psi? I've run mine at a bit over 60 psi, and I may have to back off.

But balance is first.

Bill

[[email protected]]

Originally Posted by gonzo628

We are now in our second trip, and it would appear that the Weight Distributing Hitch is beating the tar out of our camper. When I set up, I noticed a bunch of screws are loose (internally and externally). Also, my fridge was about three quarters of an inch out of the cabinet on the right side. I have the Haulmaster WDH. Any ideas?

Gonz....The "Haulmaster WDH" is rated at 1,000lbs tongue weight. I would suspect that the spring bars are rated to those specs. Meaning that they have to be very stiff to handle that load. You have a TM that probably has a tongue weight of less than half that, or 500lbs and less. When I bought my Blue Ox Sway-Pro I asked about the spring bars. On the Blue Ox, the spring bars are interchangeable, meaning that if you have two or more trailers that have different tongue weights, you can change out the spring bars to match the different tongue weights. I thought I needed the 550lb spring bars (and that's what I got) but I asked that Blue Ox people what would happen if I stepped them up to the 750lb spring bars . They told me that if I used the 750lb spring bars that the ride would be very rough because I didn't have enough weight to make the bars flex like they should. So if your spring bars are rated at 1,000lbs and you don't have a 1,000lbs or close to that tongue weight you will be getting a very rough ride. That's why your Haulmaster is beating up your TM. Maybe Haulmaster has smaller spring bars that are rated closer to your tongue weight. I'd ask, and if not, you can return the Haulmaster for a refund and look into getting the Blue Ox Sway-Pro or something like it. The Sway-Pro is not cheap....but you get what you pay for.
Tom

[Craigrrr]

I have always been under the impression that the Max weight rating of a WDH is just that. THE MAX it can do, all depends how many links of the chain you are using or not using gives the stiffness per say or the loaded spring.

The flex torsion axle of the TM takes a lot of the beating, I have the same WDH and never had a problem but I did as Bill said when I bought my new load D tires I had them spin balanced .

[tentcamper]

There is an operating range for the WDH, The weight rating is the max of that range. The manufactures don't seem to want to list the specs. It can be very hard to find the specs.

My reese 650 wdh is rated for around 400 to 650 lbs. I called the tech support to get the specs. I once tried using a 1200 whd on a light trailer. Worst bounce ride and reduced handling. I ever had with any trailer.

You can maybe play with the chain links. But not by more then +/- one link. But if you follow the instruction that came with you WDH, I think you will be within 2 links.

[gonzo628]

Originally Posted by Bill

Whatever it is, it is probably not the WDH. How did you reach that conclusion?

It is almost certainly TM tires out of balance. Tire places will tell you (as they did me) "We never balance trailer tires!" And my response is "Well, I've got the tires, and I've got the wallet. What do you want to do?"

Seriously, it is important to balance them. Another possibility is that your tires are rock-hard. By any chance are you running Load Range D tires, inflated to 65 psi? I've run mine at a bit over 60 psi, and I may have to back off.

But balance is first.

Bill

I arrived at that conclusion based on my understanding of physics (however elementary that understanding is). I figure that my WDH is rated for 10000 lb and a 1000 lb tongue weight. My camper is probably 450 - 650 lb. Because of the Sienna's relatively pathetic rear ride height / suspension, I had to invert my drop bar and mount the hitch as high as that action permitted me. Then, to achieve a relatively acceptable ride height, I had to run my spring bar chains at 6 links. Even then, the front of the tm is a bit lower than it should be.

Now, the lever action that results in the WDH lifting the tongue of the camper / rear of the tow vehicle creates energy that is transferred fore and aft of the pivot point (the ball), at least i think. (Kind of like lifting a wheelbarrel). Because those bars are pulled up so much (within six links of the shackle) I would imagine that a significant amount of energy is transferred back through the TM to its axle. These may be different principles, but I think it is somewhat a kin to how a truck (with heavy duty leaf springs) rides rough (rear end bounces around) until substantial weight is applied (causing the springs to flex -supporting the weight).

If I am understanding/applying these principles incorrectly, I would welcome the chance to learn. I do not possess any formal physics education.

As for balance/tires, I should look at that, and probably will when I return from this outing --- if I make it out (WAY TOO MUCH stuff happening -the TM is kicking my A#@ ... ahem.. rear end this weekend). Murphy has come camping with us... (wish he'd go home and leave us be). I am running 225 75R15 LRE. I have them inflated to 65lbs after Tom mentioned that he had LRE tires on "D"rims and had tire failure because his rims could not hold pressure. I surmised that my rims were probably D rated because the stamp says TM put 225/75R15 LRD on the trailer.

[gonzo628]

Originally Posted by [email protected]

Gonz....The "Haulmaster WDH" is rated at 1,000lbs tongue weight. I would suspect that the spring bars are rated to those specs. Meaning that they have to be very stiff to handle that load. You have a TM that probably has a tongue weight of less than half that, or 500lbs and less. When I bought my Blue Ox Sway-Pro I asked about the spring bars. On the Blue Ox, the spring bars are interchangeable, meaning that if you have two or more trailers that have different tongue weights, you can change out the spring bars to match the different tongue weights. I thought I needed the 550lb spring bars (and that's what I got) but I asked that Blue Ox people what would happen if I stepped them up to the 750lb spring bars . They told me that if I used the 750lb spring bars that the ride would be very rough because I didn't have enough weight to make the bars flex like they should. So if your spring bars are rated at 1,000lbs and you don't have a 1,000lbs or close to that tongue weight you will be getting a very rough ride. That's why your Haulmaster is beating up your TM. Maybe Haulmaster has smaller spring bars that are rated closer to your tongue weight. I'd ask, and if not, you can return the Haulmaster for a refund and look into getting the Blue Ox Sway-Pro or something like it. The Sway-Pro is not cheap....but you get what you pay for.
Tom

Unfortunately, I don't think I can return it for a refund (I've owned the WDH for about 6mos), but due to other things (life) I was not able to get camping before our first outing (end of last month).

[gonzo628]

Originally Posted by tentcamper

There is an operating range for the WDH, The weight rating is the max of that range. The manufactures don't seem to want to list the specs. It can be very hard to find the specs.

My reese 650 wdh is rated for around 400 to 650 lbs. I called the tech support to get the specs. I once tried using a 1200 whd on a light trailer. Worst bounce ride and reduced handling. I ever had with any trailer.

You can maybe play with the chain links. But not my more then +/- one link. But if you follow the instruction that came with you WDH, I think you will be within 2 links.

I am six links from shackle to spring bar. I think that it is too stiff a spring bar for the weight it is supporting.

[Bill]

Let me ask a follow-on question. If the WDH is thrashing the trailer, it makes sense to me that it would also be thrashing the tow vehicle, since they are attached at that point. It would be especially noticeable in a relatively light weight tow vehicle. I assume that is not happening, or you would have noticed it. On the other hand, if it is the tires that are thrashing the TM, either because they are unbalanced or because they are rock-hard, I expect that very little of this would be transferred to the tow vehicle.

Thoughts?

Bill

[ThePair]

I'm 5 links, started at 4.

Some time, very, very long ago, someone here tried to figure out an optimal weight rating for the spring bars. IIRC, it was 750-800. Anything more was too stiff, and less ran into issues with actual hitch weights, as many are 500-600. I know mine is in that 750-800 range.

I drive a Sienna too, so well aware of the issues therein.

Bill -- I agree with your logic, but there may be more than one issue at play, here. Both could be contributory.