Happijac Parts list/Repair Instruction

I had the same problem with a rear motor that would not work and Happijack told me exactly what they told you regarding a DIY repair.
I decided to call my dealer and he told me that when those motors seem seized they need to be replaced.
I mailed him the old motor and he mailed me a new one. Works fine.
Try calling your dealer.

WestCoast1969 wrote:
I am having some difficulty with the two rear motor heads on my jacks. One seized up and the other is really noisy, so I emailed Happijac about repair costs and this is what I got.

If the motor head has not been used in a while it is possible that the brushes on the motor have begun to seize. SOMETIMES you can break them free by inserting the manual hand crank in the socket (leaving the lever in the up position) and attempt to turn the handle ¼ turn. If this does not work and you are mechanical you could attempt to take the top cover off the motor head (6 screws with square head insert) and pull the gears exposing the top of the motor spindle. Wrap the spindle with a rag and apply vise grips and attempt to turn the motor.


If this fails we have a program to refurbish the motor head for $59.95. ( But does not include shipping (( this could be a high cost because of the weight and distance from and to 84037)) ).

We also have refurbished motor heads for $95.00 or new motor heads for $179.95

AN RGA MUST BE CREATED BEFORE SENDING IN THE PRODUCT. ( You can call 800 231 7440 to acquire an RGA)

In addition to the above quote I also received (6) pdf documents that contain parts list and repair instruction. See below.


45 series parts break down
4150/4160 Diagram Parts List
Cam Install
Clutch Adjustment
Outer Jack Tube Removal
Upper Assembly

Thank you very much for sharing the PDF files, they should be put in the Truck Camper University if not in there already...

Excellent Info...

KKELLER14K did an excellent write up on the 4150 thats in the TCU- adding the linked files...

3 years old? Odd parts list, instructions but nothing on the motor itself, though I suppose does tell you how to remove to send to them..

H/J didn't suggest a possibility, but think I might remove motor and verify problem is in motor and not jack assy. before investing on the options? Brush seizing-causing motor to bind? Never heard that before, curious scenario..brush sticking and not making contact-motor wont run or intermittent or spark having to jump & burning up brushes or carbonizing up. I suppose but Ive never seen brush material that was strong enough to keep motor from turning (or if jammed and manually rotated rotor would just break brushes. I must not understand their comment?

EDIT 07/2018: I have the 6 original linked H/J pdf files uploaded to google,
They can be downloaded from here...
https://drive.google.com/drive/folders/1dfkxKiCIuDGdBL8Db6SK78Maa9h1ZrbQ?usp=sharing

Thanks for the pdfs, good to have.
My camper has spent most of its life outside, and the jacks definitely show it. I can tell you a seized motor is most likely caused by a seized lower bearing, requiring complete motor disassembly or replacement. I found the correct bearing at Grainger. Someone here suggested using an air nozzle at the lower drain hole to remove the plastic cover, and I can tell you it worked well. One new motor allowed me to rebuild them one at a time without taking the camper out of service, leaving me with a spare.