Upcoming torsion bar replacement

[Larryjb]

Two torsion bars arrived today. Shipping was $80, but that was pretty much across the continent. I'm sure I could have saved shipping by having all the torsion bars I'd need shipped at once, but I can't afford to replace all the torsion bars at once, and the others weren't maxed out, as far as I know.

They were shipped in a cardboard tube, with padded cardboard on the ends. When I left the depot, the others waiting were very curious, so I told them I was joining a jousting tournament. I actually had at least one of them going for a moment! (Imagine the armor you'd need against those... oh my...)

I won't be getting to the bars for a couple of weeks, and then I'll be working out the procedure so I don't clutter the forum with useless information like jousting gear.

[BrucePerens]

I'm really interested in how much they help. My front bars are maxed out by my modification to restore the roof curvature, and I think I can make the right one larger, but the left one is already the maximum size. If they really lose a lot of strength, there's some hope for that one. I can make the rear bars larger, but I think the problem is more in the front.

[Larryjb]

Custom RV in CA showed me I could grind out the part of the frame holding the adjustment end of the torsion bar to get a few more turns of the adjustment bolt. I felt it was better to replace the bar because I don't know how the effects of metal fatigue would be. Would the torsion bar snap later? Permanently bend like an over stretched spring?

However, in your case this could be an option. You may still need to replace the bar, but you may get enough adjustment out of the bolt by that method.

How heavy is the awning? That is the reason a heavier bar is needed for the curb side. How heavy are the modifications you made?

[BrucePerens]

The modifications I made were about 65 lb. That's probably similar to the awning weight. I've thought about using the grinder method. I may yet do so.

[Bill]

Originally Posted by Larryjb

Custom RV in CA showed me I could grind out the part of the frame holding the adjustment end of the torsion bar to get a few more turns of the adjustment bolt.

Larry -

Could you clarify a bit just what you are grinding in this technique? The end of the torsion bar? The frame member itself where the fully-raised torsion bar stub butts against it? Something about the bracket?

Thanks

Bill

[BrucePerens]

It's the frame member where the cut off end of the bar sticks out. If you grind off some material, you can turn the bolt a few turns farther and twist the bar perhaps 10° more.

[Larryjb]

Thanks Bruce, you've got it. I think I have a picture of that area I took when I first got the trailer. I'll see if I can zoom in and highlight the area, unless some one beats me to it!

[Larryjb]

I snapped a couple of pictures where the torsion bar fits into the frame under the trailer. The torsion bar that lifts the awning side is maxed out, but the other side still has a lot of adjustment left. I might install just the one torsion bar and keep the other on hand.


Note the extra room in the frame that holds the torsion bar. The bolt could be screwed down more to increase tension on the torsion bar.


Note that the torsion bar has bottomed out in the oblong hole. The bolt will not be able to screw down any further to put more tension on the torsion bar.



I haven't had a chance to highlight where the frame can be ground out, but you would make the oblong hole in the frame longer towards the top. As you can see, there isn't much room, but it can buy a turn or two.

[Bill]

Thanks for the pictures, Larry. I was having trouble visualizing what was being ground.

What would you think of grinding off the top of the stub of the bar, to flatten it? As long as the grinding takes place beyond the spot where the adjustment bolt contacts the bar, there would be no weakness introduced. The problem with the bar as it is? The part of the bar that hits the oblong hole, limiting the travel, is beyond the place where the adjustment is made. I think I would be more comfortable flattening the outer tip of the bar, than enlarging a hole in the frame. But that's just me.

Bill

[Larryjb]

I imagine that would work as well. Either way, the end of the torsion bar is eventually going to contact the floor of the trailer ultimately limiting its adjustment.

I don't know how much adjustment I'm going to need at this point, so to take the bar out, grind the hole or bar, reinstall, only to find out it's not enough is not on my list of farourite things to do. I've played the game of saving worn out parts too many times. Sometimes you win, but this is a job I don't fee like doing more than once.

I'm going to have to devise a safe way to support the upper shell (I can probably do one side at a time), remove the old bar, reinstall, then adjust. I may be trying it this weekend, we'll see how things go. I still have two overdue oil changes to do on my trucks.