I'm north at my friend's house to dig up some small evergreens, and the first thing Charlie asked me to look at was his rear door on his Cargo Mate trailer. The cable had come completely off the spool, and he couldn't figure out why or how to fix it. The first thing we did was remove the metal cover over the shaft and springs. Right away I didn't like to see the 8' shaft with no center support. When he lowered the door I could see the middle of the shaft wobble around at least an inch. So, we made a wood support and used grease on it. BTW, the shaft appears to be no more than a 1" diameter conduit, and with 2 coiled springs wound up, and no center support, it just seems to be a poor design for a lightweight 8 foot shaft.
The spools for the cable have a thread type groove to feed the cable and hold it in place. The other thing I didn't like about this single shaft having two springs and a spool on each end, all working in unison, is when you lower the door on a perfectly flat surface and the trailer is also parked on the same flat surface, everything is fine, but if the ground by the door is slanted just 2", then one end of the door will rest on the ground, while the other end is up 2". Now, when you drive out of the trailer the other end of the door will lower 2" while the other end of the door doesn't move because it's already on the ground. Since both cable spools are clamped to a single shaft, the shaft will unwind the 2" for the door to drop down, but the other spools will also unwind 2" of cable and leave lots of slack. This amount of slack allows the end winding to slip off the end of the spool. Now that spool has all the rest of the cable with lots of slop, and when you raise the door all the rest of the turns fall off the spool.
It would have been smarter to use two half shafts each winding a spool, so they each keep tension on the cable at all times, even if one end of the door gets pushed down an inch or two. Anyway after a lot of hassle I got both spools adjusted with the door closed so they have no slack, but I told Charlie to be sure he only opens the rear ramp on level ground.
Another problem I encountered while trying to adjust the springs, is the springs were built with no space between their coils. Lets say the springs are 20" long and have 100 turns. Now, when you lower the door the spool will unwind 10 turns of cable. This means you have just added 10 more coils to the spring, so the spring is now 22" long. So when I first adjust the spring I had to pull the spring to stretch it 2 1/2" (1/2" extra safety measure) plus give it one turn to keep tension on the cables. The spring should have been made with air space between the coils in the first place. I don't ever recall having to pull garage door springs to stretch them before I clamped them in place. Anyway, I finally got the job done, and Charlie said the door never worked so good, so I hope this helps if you ever have a similar problem and wonder just why the cable suddenly came off the spool. The second picture also shows a 1/2" hole we discovered in each corner, which let water get inside, so we had to patch them also.
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The spools for the cable have a thread type groove to feed the cable and hold it in place. The other thing I didn't like about this single shaft having two springs and a spool on each end, all working in unison, is when you lower the door on a perfectly flat surface and the trailer is also parked on the same flat surface, everything is fine, but if the ground by the door is slanted just 2", then one end of the door will rest on the ground, while the other end is up 2". Now, when you drive out of the trailer the other end of the door will lower 2" while the other end of the door doesn't move because it's already on the ground. Since both cable spools are clamped to a single shaft, the shaft will unwind the 2" for the door to drop down, but the other spools will also unwind 2" of cable and leave lots of slack. This amount of slack allows the end winding to slip off the end of the spool. Now that spool has all the rest of the cable with lots of slop, and when you raise the door all the rest of the turns fall off the spool.
It would have been smarter to use two half shafts each winding a spool, so they each keep tension on the cable at all times, even if one end of the door gets pushed down an inch or two. Anyway after a lot of hassle I got both spools adjusted with the door closed so they have no slack, but I told Charlie to be sure he only opens the rear ramp on level ground.
Another problem I encountered while trying to adjust the springs, is the springs were built with no space between their coils. Lets say the springs are 20" long and have 100 turns. Now, when you lower the door the spool will unwind 10 turns of cable. This means you have just added 10 more coils to the spring, so the spring is now 22" long. So when I first adjust the spring I had to pull the spring to stretch it 2 1/2" (1/2" extra safety measure) plus give it one turn to keep tension on the cables. The spring should have been made with air space between the coils in the first place. I don't ever recall having to pull garage door springs to stretch them before I clamped them in place. Anyway, I finally got the job done, and Charlie said the door never worked so good, so I hope this helps if you ever have a similar problem and wonder just why the cable suddenly came off the spool. The second picture also shows a 1/2" hole we discovered in each corner, which let water get inside, so we had to patch them also.
T 001.JPG002.JPG003.JPG004.JPG006.JPG007.JPG008.JPG
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