Flippac folks beware....

[aventurero]

Greeting Fellow FP owners, Two days ago my flipped bit me! Broke a rib when the crank hit me, when it appears, the splines on either the torsion bar or hinge stripped out. The crank slammed into the truck body very close to the rear window on my 92 Toyota Pickup Extra-cab.(Glad it didn't break the window) It put a large divot in the body very close to the window. Then rebounded into my chest. Knocked the Crap out of me. So, beware. I'm going to modify the open/close mechanism to the post I saw here on AP.
On the mend. 4 weeks I'm told.
Cheers, JN

 

[czukie]

Torsion bar failure? or can you be more specific

 

[WOODY2]

Operator error?

 

[DVexile]

Torsion bar failure? or can you be more specific

Operator error?

He already made that pretty clear:

Broken rib from the crank when the splines on either the torsion bar or hinge stripped out.

When the splines fail the torsion bar immediately unloads itself spinning at very high velocity. The lid doesn't move at all - the bar just spins inside the bearings. If you've got the crank arm attached when this happens - ouch. Has happened before, someone reported the same failure in another Flip-Pac thread in the past few years.

It seems the act of trying to open/close the Flip-Pac causes barely held splines to let go - meaning most likely to happen while you are holding onto the crank arm!

 

[aventurero]

Further Inspection.....

Greetings, Yesterday, I was in the mood to investigate the failure of the Torsion Bar/Hinge Splines. I pulled the Nylon doughnut out of the lower half of the hinge. Then placed the crank on the Torsion Bar. Then, flexed the Bar a little. The splines on the upper portion of the hinge (the portion the fits into the lid) had indeed failed.
JN

Not sure why the image was rotated?

 

[CactusJackSlade]

Greetings, Yesterday, I was in the mood to investigate the failure of the Torsion Bar/Hinge Splines. I pulled the Nylon doughnut out of the lower half of the hinge. Then placed the crank on the Torsion Bar. Then, flexed the Bar a little. The splines on the upper portion of the hinge (the portion the fits into the lid) had indeed failed.
JN
View attachment 402925
Not sure why the image was rotated?

Would you mind posting photos of the nylon bushing and the spline area?

 

[aventurero]

I will when I get it pulled apart. I'm assembling the parts to convert it to modification the Timber shows on his post.

 

[aventurero]

Ah Ha....

Greetings, Well. Took the torsion bar out of the hinges today. Turns out that the bar is in great shape as are the hinges and the splines. What caused the crank to hit my crank and then me was that the splines were not Fully engaged with the hinge. I'll take a pic of it tomorrow. Only about a 3/16" of the splines were engaged on the driver side hinge. The torsion bar must have very slowly over time migrated toward the driver side so that only a fraction of the splines were engaged. So, I haven't decided whether to continue with the push bar modification or just put it back together. If I put it back together, I'll certainly make sure that the splines are Fully engaged.

 

[CactusJackSlade]

Greetings, Well. Took the torsion bar out of the hinges today. Turns out that the bar is in great shape as are the hinges and the splines. What caused the crank to hit my crank and then me was that the splines were not Fully engaged with the hinge. I'll take a pic of it tomorrow. Only about a 3/16" of the splines were engaged on the driver side hinge. The torsion bar must have very slowly over time migrated toward the driver side so that only a fraction of the splines were engaged. So, I haven't decided whether to continue with the modification to a push bar arrangement or just put it back together. If I put it back together, I'll certainly make sure that the splines are Fully engaged.

Interesting find - good to know, and check up on... picture or two if you can!

 

[aventurero]

 

[DVexile]

Thanks for the picture! So if I understand what you are saying and looking at the picture right it seems the torsion bar slowly worked its way to the driver side over time. Eventually only a small portion of the splines were engaged with the hinge on the drivers side. It looks like from the picture the last little bits of the splines then sheered causing the bar to unload/spin on you. Did I get that right?

Really important failure mode to know about - and a pretty easy one to monitor now that I know to look for it! Thanks again for the warning.

 

[ToyotaRoamer86]

What does flip pac say about this kind of failure?

 

[DVexile]

What does flip pac say about this kind of failure?

Nothing, they have been out of business for about a year now.