Gas struts for hard tonneau cover.

[Drkhorse]

I have an 04 sport trac with a hard tonneau cover that folds in half and I’d like to put gas struts on the back half. I’m assuming ford didn’t have this available so I’m assuming it’ll be a custom install. With that being said, has anyone done this and if so how did you do it? I’ve done some research, which brings me more questions than answers, like how long should the struts be? Can I buy proper mounting hardware or will I need to make custom hardware? I’m only looking to lift it to a 45 to 60 degree angle and I’m open to any and all advice offered.
Thanks in advance, Gary

 

[429CJ-3X2]

That's an interesting idea! I have a 1 piece hard cover that was on my 2001 Sport Trac. This is the hinge system it uses. One end of the strut attaches to the end of the hinge where the bracket is screwed to the cover and the other end attaches to the knob at the bottom of the v on the other arm. The cover is just strapped to the original box for the '01 which is sitting on blocks, so I can't open it for a better look. Of course, the 1 piece cover hinges at the front, so these measurements are all wrong for our hinged covers.

 

[429CJ-3X2]

There are several problems I see with attaching struts to the hinged covers. The easiest place to attach the struts would be in front of the latch, but any strut that would hold the cover up that close to the hinge would have to be too stiff to close easily. If the strut was attached to the rear of the latch, it would probably to be too long to close. Maybe a setup like the hood hinges and struts would work? I don't know what the geometry would have to be for this to work.
The hinge system above is attached to both the cover and a frame that clamps to the bed.
This did prompt me to put a prop rod in the 2004 with the factory cover and order new struts for the topper on my '02!

 

[Drkhorse]

I was wanting to mount the gas struts a few inches in front of the hinge in the middle of the cover, the only strut that will fit is a 10 inch. There is 13.5 inches between the hinge and cover latch. I think I can do this, I was hoping others have done this so I could glean some knowledge.

 

[429CJ-3X2]

The struts used on my topper are SUSPRA C16-04154. They are probably close in measurements to what you need, but you'll need stronger ones. These are rated at 24 lbs and struggle to keep the rear window up in cool weather once they get a little age on them. Open, they measure 15" end to end. Closed, they're 10 1/2 end to end. I think the official measurement are from center to center of ball openings, not end to end. I just ordered a pair on eBay and happened to be sitting on the tailgate when I read your reply.

 

[Drkhorse]

Thanks, I’ll check that out. If I have to use anything longer I may have to attach the top end on the inside of the latch on a slight angle in-ward. Overlook the string, it was there when I bought it, I’m working on fixing that too

 

[Drkhorse]

I think I found something I could use, what do you think?
15 inch struts

 

[429CJ-3X2]

The length seems good, but I wonder if 67 lbs is too much. It's been a long time ago, but I remember reading that the bed cover weighs 80-85 lbs. After lifting a couple, I'd say they weigh at least that. If that's accurate, the rear section should be 40-45 lbs. The 55 lb struts might be better. On the other hand, the 67s are cheaper. Too light, won't hold the cover up. Too heavy will be hard to close and put more wear on the mounting points. The latch housing is rather thin, but strong as I recall. I would bolt the L mounts to the bed horizontally if they'll work that way. I assume the steel reinforcement runs the length of the bed, but I don't know how wide it is. Since I've (willingly) gotten myself sucked into this project, I can drill a couple of holes in my old bed to see what's behind the side wall. The tailgate hinge area is totally rusted out, so that bed is only good for parts or maybe a trailer project.

 

[Drkhorse]

No need to do that, I can check it with a magnet. There is a 45lb also. I appreciate all you help, thanks.

 

[429CJ-3X2]

No problem! I'm invested in this now!
I just propped the cover up with a bathroom scale under the prop, and it only registered 25 lbs just ahead of the mid-point, and 20 lbs with the prop near the tailgate. The 45 lb struts might be the way to go. If you're wanting the struts to lift the cover, they'll need to be stronger than if you just want to hold it up. The struts on my topper door are 24 lbs, and the door probably doesn't weigh over 7 or 8 pounds, if that. When they're new, the door snaps open, but they weaken with age and eventually won't hold it up. Of course, that door goes from near vertical past horizontal to near vertical the other way - well past 90 degrees of travel. The cover will only be going from horizontal to 45-60 degrees.

 

[Drkhorse]

Well I would like them to lift and hold. It’s a bit awkward to lift it with the tailgate down.

 

[429CJ-3X2]

The 24# of pressure I measured last night only applies to a vertical prop/strut. It'll take more pressure at the angle you're planning. I think a more vertical strut placement would work better and provide more assistance. The downsides are the struts would intrude more into usable space and the bed side mount would likely be anchored in just the composite side wall. I don't know how much of a problem that would be. The strut mount on the cover could be placed behind the latch assembly (behind meaning closer to the hinge).

Yeah, they are a pain to lift with the tailgate down.

 

[Drkhorse]

Ok, what if I took some 1/8 aluminum plate and shaped it in a way so I could attach it so I could mount it similar to this? It would cost more but would work much better. It would use a longer strut. I’m thinking this would be a better design after I put pen to paper and work out the final design.

 

[429CJ-3X2]

I think I'd just attach to the bed side without reinforcement and check it often before going to that much work. If you think it's starting to wear too much or working loose you can always add reinforcement. Maybe a piece of wood or metal between the bottom of the strut mount and the floor would work. Probably wouldn't have to go to the floor as long as it was screwed to the wall in 3 or 4 spots. Could even be horizontal. That way the force isn't just on the 2 screws/rivets of the L mount.
Granted, topper doors aren't heavy, but the struts mounts attach to a thin piece of aluminum.

 

[Drkhorse]

Yeah, sounds reasonable. I know I’m overthinking this, less is more. I’m gonna do some more measuring and gather my parts and I’ll document what I do and post it if anyone else wants to do this. Thanks for all your help, I greatly appreciate it.

 

[429CJ-3X2]

I was looking for something in my garage before we started this discussion and saw a strut I'd taken off something - probably the 1 piece cover. It's way too stiff at 105 lbs - I can't even budge it when I lean on it against the concrete driveway - but the length looks right for this project. It's 19.7" from center of hole to center of hole when extended. End to end when collapsed would be right at 12". I held it in place with my truck and cover and it should hold the cover somewhere between 45 and 60 degrees, probably closer to 60.

I also drilled a couple of holes in my old bed side. The side wall looks to be about 1/8" thick and is reasonably stout.

 

[Drkhorse]

Yeah I was looking at mine and it is pretty stout. I also did some more measuring and if I just use a 2inch wide strip to mount the struts to bolted to the bed as shown I could use 15 to 16 inch overall, and closed 8 inches. I do have room to adjust longer or shorter by going up or down the mounting strip.

 

[Drkhorse]

In fact, now that I think about I could use the location of the tie down loop as a mounting location and just use a 20 inch strut and call it a day.

 

[429CJ-3X2]

I thought the same thing when I was looking at it earlier when I had the strut in hand.

 

[Drkhorse]

I love it when a plan comes together!