Harbor Freight Motorcycle Lift - Pointed Set Screw Purpose?

[mcman56]

My HF lift has a pointed set screw where the large shaft goes through the center triangular part. See picture. There are just a couple of threads so it falls out but does not seem to affect anything. Does anyone know exactly what it is supposed to do? Without disassembly, it looks like there is a solid shaft that goes all of the way through the end supports. There is then what looks like a long steel bush going all of the way through the triangular part. It looks like the pointed set screw could be intended to prevent the bush from rotating in the triangular part but I'm not sure why. Could it be there to ensure bush to shaft wear instead of bush to triangular part wear that could result in a lift failure. I'm not sure if I need to come up with a fix or not.

 

[jabberwoki]

Scary...

 

[rancherbill]

I have never seen one in real life. It looks like it should have a grease fitting.

I am interested what the experts say.

 

[mikegt4]

Probably to prevent the long shaft from walking axially in the triangle part and potentially disengaging from the pivot bushing on the frame.

 

[mcman56]

I finally pulled it apart and yes it must there be to prevent axial movement. It was threaded into a tube with maybe a 3/32 wall so must be a very common failure. It seems like a good solution would be to weld on a nut but I'm not a great welder and don't have a good way to clear out that tube if somehow I got a blob of weld inside. I decided to make a slip-on C shape threaded for an M8 screw that goes through hole in the tube and into the detent in the shaft. It seems to work OK. I also saw that there was no grease or grease fittings for where the shaft does rotate. Due to no grease the shaft was already starting to wear. I opened some existing holes for M6 grease fittings.