Happijac motor drive

[racedrvr]

I have a Bigfoot with Happijacs. One of them keeps blowing the fuse. The jack moves freely when manually cranking the jack. Do any of you know if all the jacks use the same drive motor assembly? I have 4500 series jacks on mine, and I am looking to replace the bad one. I don't know for sure what the part number would be. I have found 600510. Will that work?

[DWeikert]

RamTC wrote:
All the motors are the same and it's almost always the bottom bearing that falls apart. If you're handy, you can replace the top and bottom bearing and the whole drive assy is as good as new for less than $10. As soon as these motors give off the sound of nuts in a blender, it's the bearings.

None of my motors ever had any unusual sound. The work fine one time, then the next it's frozen.

[RamTC]

All the motors are the same and it's almost always the bottom bearing that falls apart. If you're handy, you can replace the top and bottom bearing and the whole drive assy is as good as new for less than $10. As soon as these motors give off the sound of nuts in a blender, it's the bearings.

[racedrvr]

Wow, thanks for the replies. It sure sounds like I am not the only one with this issue! I may get a refurbished one, and send mine in for repair to use as a spare. I sure am glad they can be hand cranked. It saved me a lot of grief getting the camper off my hunting grounds and back on the truck at the end of the season.

Thanks again guys!

[DWeikert]

Just sent 3 HJ motor assemblies back to be rebuilt. Motor seize and blowing fuses. One motor failed a couple years ago, for the second time, and I bought a replacement with intentions of sending the dead back for repair and keeping it as a spare, which I never got around to. This fall I found the new(ish) motor had failed along with one of the others (both rear). So all 3 went back. HJ appears to have a water intrusion problem that I'm not sure their even working on. Their suggestion is to wrap them in a plastic bag when driving/storing in the rain. Sigh...

[bigfootgrey]

I replaced both 4500 motor heads 3 months ago. Both were front jacks on camper,full of water and rust. Happi jac said the seal goes bad on motor covers. Motors kept blowing fuses,rear jacks were fine. No problems with jacks,just motors. I keep them all covered when possible! Part number I have is182515

Bob

[portscanner]

Make sure you inspect the wiring all the way from the drive motor all the way back to the controller. Look for damage to the wiring and feel the harness for where there could be breaks in the wire or where the manufacturer put in splices in the wire.

You could have a short in the windings of the motor - but you could also have bad wiring going between the controller and the motor.

I got messed up on one of my jacks due to a bad splice. The wire from the motor one the jack was connected to two wires with wire nuts. Then 6" down that wire they had spliced the wire again and covered the entire length with electrical tape down to where the plug goes into the back of the camper. The splice they had hidden with tape (and it was a horrible splice) was hidden well and was causing me problems to the point I thought I had a bad motor. I found the bad splice only after a very close inspection of the cable.

If you have a volt/ohm meter and know how to use it, test the wiring first. If you dont have a meter or dont know how to use it, find a friend who knows how to do low voltage electrical work and have him help you test it. It might just save you the cost of buying something you dont need.

[HMS_Beagle]

On my prior bigfoot, 4500 jacks were fitted to the front and 4150 to the back. They had the same motors.

[racedrvr]

Thanks for the reminder Artum. I have read through the jack section and there is excellent info there. The one topic not discussed is the drive motor system itself. I suspect all the Happijac motor drives are the same as they appear to be the same from model to model. The ones on my 4150's look and run just like the ones on my 4500. I would just like for someone to confirm.

[Artum_Snowbird]

Have a look at the front of this section in Truck Campers under Truck camper University. Go way down to the section on Camper Jacks and look in there. There is complete take apart and lubricate instructions, parts lists, etc available there.

I took apart and lubed all four of my jacks in a day.. first one was 3 hours careful... by the fourth it only took an hour. I came up with a rig into my battery drill so that I could run the screw up and down with one hand as I applied grease lube to the threads.

Check it out, hope you find your answers.