Permobil M400 issues

[Gearhead]

I could not figure out how to jack it up since my jack is pretty tall to test the motors. I will have to wait until my wife gets home with our van with the power lift for further testing on that.


However, a couple things I noticed, 3 out of the 4 casters to not turn very freely. They take a little bit of force. Does that sound like those bearings are bad? Also I can go in reverse and it seems to work pretty good, even turning both ways. Does that make any sense? Thanks again!

IF you have power seat tilt you can use that function as a jack. With foot plates flipped up, tilt seat enough to allow a 4x4 wood to fit under foot rest mount center. Then tilt forward, foot rest mount will contact 4x4 and raise front casters and hopefully center drive wheels (I know it works on FWD). Put another 4x4 under chair frame for safety (as a jack stand). Hopefully you can run motors off the ground to listen to them too.

I had a M300 that casters didn't swivel freely when new. Tech came out and installed some sort of updated washers to caster swivel. They still didn't swivel/pivot freely. A slight swivel drag is needed to reduce caster flutter. Caster wheels should roll freely. If not, check for string, rope, cloth remnants tangled up in wheel axle.

Reminder, if you have a caster wheel dragging so much that you have to compensate with joystick, bad caster should slide (verses roll) on some surfaces.

[dmccoyks]

Thanks for the idea of lifting with the tilt. I will test that out tomorrow. One of the 4 casters will swivel about 1 turn by just giving it good flip. The other 3 will not turn at all when I try to flip and can only be turned by some force to move it around.

I lifted my chair this evening, ran the motors and they both seem to turn the wheels okay as far as I can tell. I also disengaged the motors on each side and rotated each wheel by hand, they both seemed to rotate smoothly, however the left one makes a whining noise while rotating and the right one is quiet. Any thoughts?

[Rustyjames]

It's possible that motor got hurt, but I'd get the caster situation cleared up and go from there. It's not uncommon for a motor/gearbox to have some noise but still be serviceable.

[dmccoyks]

That is my next step to replace them in the next few days when the parts arrive. I was thinking though if it is the bearings then wouldn?t it affect turning both ways and not just to the right side? Also wouldn?t it affect it turning when both ways in reverse.

[Rustyjames]

You mentioning that three of four casters are stiff so there's no telling how it'll act. As far as reverse being better that might be because the bearing could be "unbinding" allowing it to travel easier.

[dmccoyks]

Okay I will replace them and see. I also removed both of the motors today and I am going to open them and look at the brushes etc. and see if anything looks bad. Thanks again.

[dmccoyks]

Another question if you don’t mind. I want to replace my grey tires with black ones while it is apart. What are the largest size tires I can put on the front and rear casters. They show 200x50 on the current ones.

[Rustyjames]

I don't think there's an available next size up that'll work, but not sure. Honestly, I'm not familiar with Permobile, but You might be able to get more info about that question on the forums at wheelchairdriver.com.

[dmccoyks]

Okay I will ask there. Thanks

[dmccoyks]

I wanted to post an update to my issues and let you know what fixed the problem. It turned out to be my left motor was the issue. I ended up taking it apart and it had a lot of carbon build up on the commutator of the motor. I cleaned it with some fine grit sandpaper as well as the brushes and it is working great. See enclosed pictures of before and after the motors were cleaned. Also as you can see the left motor is much worst then the right one. I appreciate everyone?s help.

[dmccoyks]

First picture didn?t upload.

[Gearhead]

Looks like Rt one had brush skipping.

[nonoise]

Nice work. I would order new brushes to install later. The original curvature is difficult to replicate.

[dmccoyks]

Thank you. Someone mentioned I should run the motors without any load for approximately an hour to help conform the brushes since I smoothed them out or when I replace. Does that sound right to you guys?

I would like to order new brushes, but I don’t know where to get them or know the true sizes. Does anyone know the sizes or part # and where to order replacements?

[nonoise]

These should be fairly available.

Try this site https://store.eurtonelectric.com/brushes.aspx , but first check our their youtube.
https://www.youtube.com/watch?v=J7yo0PheRzE