PM932 Popping out of gear!

[tlmartin84]

As of today, my mill has started popping out of Low and migrating towards High. As long as I hold some pressure on it, it is fine.

I talked to Quality Machine and they said I would have to open it up.

Just curious if anyone else has had this issue, or saw any other members with this problem.

 

[benmychree]

Sounds like worn gearing. I have a 19" Regal lathe that did that in high range, it turned out to be that apparently the helical gear that drove a dog clutch wobbled a bit under power and the dog clutch wobbled out of engagement and into the next tooth space with a big CLUNK! I had to recut the clutch teeth to solve the problem, and taking lighter cuts also helped.

 

[gb1551]

I have the same problem with my MP932, manufactured in 2015. On semi-heavy cuts or cuts that have vibration, the lever kicks out of third gear on its own.
I opened the gearhead and inspected the gears and shifters. It all looks fine to me. I think the problem is a weak spring (part#40). This spring pushes an 8mm steel ball (part#39) in an indented groove on the shaft keeping it in gear. I added more pressure on the ball by stretching the spring about 100 thousandths, so it will stay in the groove and not bounce out. So far, I use the mill a few times without any problem with popping out of gear. I hope it continues without issues





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[tlmartin84]

I have the same problem with my MP932, manufactured in 2015. On semi-heavy cuts or cuts that have vibration, the lever kicks out of third gear on its own.
I opened the gearhead and inspected the gears and shifters. It all looks fine to me. I think the problem is a weak spring (part#40). This spring pushes an 8mm steel ball (part#39) in an indented groove on the shaft keeping it in gear. I added more pressure on the ball by stretching the spring about 100 thousandths, so it will stay in the groove and not bounce out. So far, I use the mill a few times without any problem with popping out of gear. I hope it continues without issues





.

Thank you for this information. I may try to replace the spring all together. Mine only does it with large drill bits/chucks, that have some "wobble" to them. Any vibration, and it pops out.

Did you have to drain the oil to get to it?

 

[COMachinist]

I have my PM932 head disassembled right now to replace oil seals and bearings. One of the most worn part I noticed is the shifting forks. I replaced them just incase they became a problem. Check them for a loose shaft set screw.
CH

 

[tlmartin84]

Thanks guys, this has to be something simple. it only has a few hundred hours of run time...if that.

Anything I need to watch for when opening up the case, flying pins, springs, etc.

 

[gb1551]

I would go through Quality Machine since the machine is new and may very well be under warranty. Let the direct you. They can forward you instructions.

 

[tlmartin84]

I would go through Quality Machine since the machine is new and may very well be under warranty. Let the direct you. They can forward you instructions.

I contacted them. It is out of warranty so repairs are on me.

 

[COMachinist]

Oh, if you did not drain and clean the gear box before you ran it. You will definitely need 3 new 6003zz double sealed bearings on bottom of your gear train shafts. Mine has less than 30 hrs on it, and they were toast. The tops bearings are good.
CH

 

[tlmartin84]

Oh, if you did not drain and clean the gear box before you ran it. You will definitely need 3 new 6003zz double sealed bearings on bottom of your gear train shafts. Mine has less than 30 hrs on it, and they were toast. The tops bearings are good.
CH

It was drained and new fluid put in it. I did not pull the head.