FWC Locking Turnbuckles - Do They Work? Long Enough?

Couple things to keep in mind with components is WLL is typically a ratio vs ultimate breaking strength (often 3:1). You aren’t lifting up a 1200lb camper with these, you’re holding it in place along with gravity and friction.

All that said they make forged steel turnbuckles rather than bent hook ones if you prefer.
 
If you store your camper & truck upside down, then 4 times 215 would definitely be an inadequate WLL to hold the suspended camper to the truck. However, the truck bed is supporting the major load of the camper weight. This means that the turnbuckles are adding to that force keeping the camper in place.
I assume you are not jumping your truck/camper combo in normal use, so the factory turnbuckles sized based on decades of keeping campers in a fixed position within the truck bed and relying on gravity as the major force to keep the two together. :)
What we don’t know here is what WLL is needed for the turnbuckles to keep the camper in a fixed position within design limits of normal use.
With thousands of campers built, sold, & in use, both FWC & ATC have probably determined what WLL is required.
On the other hand, Toyota determined that my Tundra only needed load range C passenger tires & I thought load range E was more appropriate so I understand the belt & suspenders approach.

Paul
 
Those look like the same aluminum-bodied turnbuckles the dealer supplied with my new Grandby in 2021. I think there are many of us here (if not the majority) using the supplied aluminum turnbuckles. I have only seen one thread in the last few years (it was in the last few weeks) where a user said he was repeatedly finding one broken. That thread didn’t really identify why they broke.

The far more common discussion is about methods to prevent the turnbuckles from becoming loose - lock nuts, lockwire schemes, strap arrangements, and most recently pins.

If your truck frame is fairly rigid in torsion, the peak loads on the turnbuckles and the attachment system will likely be associated with off roading rocking and rolling, or accidentally hitting a curb, etc. Service experience with the aluminum turnbuckles for those loads seems to be very good.

If you have a truck that flexes a lot in torsion and causes the bed to twist, the peak loads on your the attachment system will probably be associated with the truck twisting while off roading or entering driveways at an angle, etc. The attachment system will try to twist the camper along with the bed. Trucks like this probably should have some flexibility built into the front two attachment systems. The brackets on the newer campers (which replaced eye bolts on the older campers) provide a small amount of spring function, but beyond that, either the camper has to twist or the bracket attachments to the camper, your truck bed attachment, or the turnbuckle has to give. Having hell-for-stout turnbuckles doesn’t solve that problem. It just ensures any overload failure happens somewhere else - and probably a far more expensive somewhere else. I don’t have personal experience with the Tundra, but others here do and maybe can comment on how much they twist under diagonal loading.

I would suggest starting out by using the supplied turnbuckles, and pay attention to properly reinforcing your bed mounts. Then inspect them regularly as you use the camper. I also recommend using locknuts on the right hand threaded side of the turnbuckles. Some use nylock nuts for an extra measure. I have been using wing nuts successfully. I don’t ever find them loose.

I can look at my turnbuckles later this morning to see if they are marked for working load and post what they say.
 
+1 to what others have said here. I have been using Torklift Fasgun Derringer's on my campers for years now. Even they came loose once after a particularily exciting dip/rise/dip in the road at speed. Didn't think of it at the time, and only realized there was a problem back in camp after completing the Capitol Reef Cathedral loop road that day. Camper was sitting back about 4" :oops: :oops::oops:

And in a Hawk I had, I tore out the bolt from the camper side. Upgraded to the aluminum plate and climbing hanger style that FWC uses now, no more issues.

So, if you did hit some unusual road conditions, check those turnbuckles!
 
I could not find any label of working load or anything else on the turnbuckles that were supplied with my camper by the authorized dealer (Mule Outfitters).
 

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Thank you everyone for the responses. Maybe the high WLL versions are overkill. I did order some of the ones listed by @csasper before seeing all of your posts. Maybe I will try the originals and keep the new ones in camper if one breaks.
 
I used those turnbuckles for about 10 years with an Eagle. They should be fine as long as they are kept tight. If they loosen, far more force is applied as the truck bounces.

I did have one turnbuckle where the hook pulled partly open. There are a number of threads on how to keep the turnbuckles from loosening, but also realize that there will be some side-to-side, front-to-back settling of the camper, particularly after mounting the camper on your truck.

I later used Derringer Quick Draws. They don't loosen. With the Tacoma bed mounts, after the first 500 miles or so of rough road, the Quick Draws stay tight. On the Ranger, the truck bed must be reinforced, and even then there may be some slight bed deformation, so you still need to check your tie-downs periodically.

We are switching from the 2-door Ranger to a 4-door Tacoma, and it looks like, based on the comments above, the new locking turnbuckles will be as good as the Quick Draws and far easier to adjust.
 
I agree with Jon R and the others. You want a weak link in the system in an inexpensive part. We'd design in a "fuse" in aircraft structures that was easy to replace (obviously where a load failure wasn't catastrophic!).

We've broken one turnbuckle hook and bent two others in 80,000 miles. So it can happen. We check the turnbuckles, especially after rough rock 'n roll roads. You don't want your camper falling off like they guy on the Swansea-Cerro Gordo road! I wonder if I was overtightening the turnbuckles early in our camper career. We carry two or three spares but have never had to swap in more than one on a trip.

Our camper tends to shift to the left, perhaps because the heavy components are on that side. So we've had to tighten the left side quite a bit after bumpy terrain. Come to think of it, the right side seems to be where the failed turnbuckles were.

I like the wing nut idea. We use regular jam nuts on the RH threads, and the forward turnbuckles are pretty awkward to work on. Jam nuts made a huge difference. They weren't supplied with our camper (also from Mule, one of their earlier sales). Before we added the jam nuts, we had them loosen to the point they unhooked.

I've noticed we have some wear in the camper brackets where the turnbuckle hooks are tugging on them.
 
that makes 3 recommendations in one thread for the Derringers. Hmm. Good advice? Probably.
I can’t speak to Derringers, but I am a fan of TorkLift FastGuns, same principle, but longer for external tie down. I don’t think I’d ever go back to turnbuckles, unless there’s no other viable option.
 
So how would one determine the right Derringer units to replace factory turnbuckles for a 2010 Tundra DC and a 2014 front dinette Hawk?
 
For my Hawk, I purchased the Torklift Derringers, I replaced the 1/2" treaded hook with a longer unit, added quick links, adjusted to each corner, marked each unit for each position and done. The derringers have a locking pin to prevent them from coming opened. The nice thing you can adjust the tension so it does not apply to much force to camper structure and bed floor. I also added 1/4 plates under the bed.
 
So how would one determine the right Derringer units to replace factory turnbuckles for a 2010 Tundra DC and a 2014 front dinette Hawk?
Edited because, as Vic points out below, the only Torklift product that allows a short enough tiedown for our campers is what’s called the Derringer Handles on their web site.

If you wish to have a non-loosening tie-down that can be installed faster (using a well designed quick release device) and don’t want any additional flexibility in the tie downs, then the Derringer handles are what you would use. You would need to separately obtain half-inch threaded hooks of the right length for one end of each tie down, and one way or another lock the threads of the half inch hook so it can’t come loose.

If you are trying to introduce additional flexibility in one or both pairs of tie downs, the only product from Torklift that looks like it could fit into a short enough turnbuckle assembly is the Basic Springload. They don’t sell them separately on the web site (they include chain and a turnbuckle), but when I talked to the company a couple of years ago the guy on the phone seemed willing to sell me the parts separately.

In my opinion, for a slide-in FWC installation, whether you really need the flexibility of spring loaded tie downs is determined by how much your truck bed twists in response to the diagonal loads applied based on both the flexibility of your truck and the type of driving you do. If I thought I needed flexible tie downs, I would only install them at the front. You don’t need or want all four tie downs to have a lot of flexibility or your camper may move more than you want.

The rear flare of the camper is wider, and due to that I think that’s the end you want to keep planted in full contact with the bed if the bed is twisting. The front of the camper tub is less than 48 inches wide, so that’s the end where I would allow some lifting one or the other corner to occur when the bed twists so that the camper attachment fittings and the camper are not not forced to move with the twisting bed floor. Forcing them to move with the bed floor when the bed twists excessively would introduce very high tie down loads, possibly tearing out the camper fitting or bed eye. If the tie down doesn’t fail you flex the camper frame excessively, potentially causing damage to the camper.

My GMC hd truck is very stiff in twist and I haven’t worried about needing additional flexibility in the tie down system. Some other truck types are more flexible in twist, and might cause you to consider adding flexibility. I think for most people though who have a more flexible truck type, their careful driving habits still prevent them from really needing spring loaded front tie downs. Nothing wrong with being conservative and having that flexibility, though, as long as it doesn’t allow your camper to move around excessively in normal driving. The right kind of rubber mat really helps for that.
 
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I can’t speak to Derringers, but I am a fan of TorkLift FastGuns, same principle, but longer for external tie down. I don’t think I’d ever go back to turnbuckles, unless there’s no other viable option.
I used Fastguns when I had my Northern Lite hard sided camper and Torklift makes great products. I will have to take a look at these Derringers in the future but right now I have no problem with the standard FWC install. I did run nylon straps with cam buckles through the center of the turnbuckles so they cannot come lose and so far that is working great. I also keep my camper on my truck full time.
 
Another vote for simply using a second or jam nut to keep tie down at desired tension....bounced the Hawk on our Tundra over a lot of gawd awful stuff off roading....took a pounding and stayed intact and tight..

Strap is an innovative idea....but we load a lot of stuff out side the Hawk box between the two tie downs...strap would cut down that storage area and like I said so far KIS and jam nut is working fine...

Just for our use anything outside the bed of the Tundra or hanging off the Hawk is a No-No...tight areas off road can hook anything protruding creating a disaster ....so corner jacks and outside tie downs are not on our menu....
 
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@PaulT who asked "So how would one determine the right Derringer units to replace factory turnbuckles for a 2010 Tundra DC and a 2014 front dinette Hawk?"

There is only one fasgun/derringer. It is just the "handgun" part of the usual outside mounted units, and is ideal for short and tucked away applications like ours. To get the lengths right, I got a whole bunch of 1/2" forged eyehooks at Princess Auto, 12" length. I cut the ends open to turn them into hooks. And then via trial and error, got the length of each cut 'just right" (sometimes with the addition of a quick link) to get the tension right (hard but not impossible) in each corner of the camper/truck. Clearly label each one, and then (nearly) forget about them. AND ADD LOCKTITE to the threads or these will unscrew, and you will be back with "how did those come off" puzzlement. (ask my how I know?)

I'd check them again a few times in the first few 100 miles, and after a nasty bump or three.
 

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