Gas springs weight for cap or camper shell

Hey folks, happy pres. day!

I'm trying to figure out what weight rating to buy. I used a luggage scale to lift my cap rear glass with no spring assist from one of the spring mount points. If I lift gently it maxes out at 10 lb. And only 15 lb. If I pull it up rather sharply.

Does this mean I need two ten pound springs (the lowest I can find). That would be weight plus at least 5 lb. Extra.

Or should I go a little heavier with two 20 lb. Springs? That's the next highest weight I can find but twice the weight seems excessive.

I want it to lift and stay up easily (this is a serious concern for any man, LOL), but I don't want to have to push down the excess 20 lb. of weight if I close down the glass.

It's a all glass window so fairly light.

Background for the curious:
I have a "free" truck cap I got on craigslist. It is, of course, rough and needs lots of stuff. It came to me with one gas spring or shock or strut or whatever to hold the back glass window up instead of two. I'm pretty sure the owner used whatever they could scrounge and the one had more than double the weight rating needed. So I can't simply match with whatever it came with originally. I'm not even sure what kind of cap it is.

Thanks!

 

I was going to suggest going to the manufacturers site and looking for replacement parts but it sounds like you need to determine make for that. Is there a serial # plate? My leer has one inside left over drivers side tail-light.
Otherwise, I’ve been looking for them for my topper on Amazon and some of the other parts sites. It doesnt hurt if the struts are a little strong.

 

Thanks. Yeah, little chance on getting the manufacturer. I've been all over the thing like a fat kid on a cupcake and haven't found anything. The prior owner doesn't remember.

It was free, and probably... Maybe worth it. The prior owner swears it was for a second gen and I know he ran it on his (same truck as mine I a different color), and it does fit well but it's completely flat across the front where the second gen has that front of the bed box wall that drops about 3/4" below the side rails. I'm just going to fill that gap in with some painted wood and seals. I suspect it might pre date the second gen actually, it's either an older cap or it was really treated rough. I think it was kind of a cheap or cheaply made cap even originally. I wonder if a cap shop sold him a used cap for his second gen on the cheap as a "this cap is for your truck and we'll color match it for $xxx" kind of thing when it fit by size but was actually for a ranger or something older.

So anyway, not surprising for something that was completely free... it's got issues.

I'll end up putting a few hundred into it by the time I replace t handles, hardware, struts, seals, and herculiner it. I think it's worth that and it's mostly an experiment for me to learn about caps and figure out if I even want to run one. I can't touch anything better aground here for that price. If I like it, and I'm just not happy with the quality, I'll save up and buy a better newer one later.

Thanks for any opinions!

 

This is what I believe will work for mine...
https://www.siraweb.com/gas-prop-c1...MImqTditiZ4AIVkIvICh29OwS2EAQYDiABEgL5uvD_BwE

 

And this is my topper with an all glass (frameless) rear hatch.
I believe regular cabs have rear windows that are closer to vertical, with access and double cabs sloped more...affects cab fit.

 

Thanks. Nice truck!

Looks like those are 24 lb. springs. I suspect the extra spring rate might help in windy conditions, ice on the glass, keeping them effective as the springs age, making the glass come up quickly and easily rather than sluggishly, etc.

I think I'll go ahead and order (or get) two 20 lb. springs and see how those work. If they are wrong I might just have to sell them on and reorder, which would be a loss but not a huge one. Or perhaps I can find something at the local auto parts store to try that could be readily returned.

When I said the front was flat I meant the bottom of the front of the cap where it seals to the bed. The front of the cap shape follows the contour of the truck cab (DC/LB) perfectly. It's hard to describe but doesn't matter much to the spring question anyway.

Anyway thanks for all the help!