How Do I Remove Pinion Gears When The Hex Head Is Stripped?

[rb99]

I am trying to change out my old pinion gears and the allen head grub screws are sort of stripped. I have heated them but to no avail.

One of them I used bolt pullers and it came off but scored the shaft all the way up as it scraped off.

I don't want to drill them out because I think the gears are still good, I just have some new ones that are 25 teeth from 20.

[Brady Watson]

This is probably too little too late...but the correct wrench size is 1/8"...not 3mm. The wrench needs to be square ended, not ball ended - or the head will strip.

I would try a fresh 1/8" wrench from the hardware store and mash it down in there as you try turning it. Buy a few. They are cheap. You might get lucky. I would give up on the heat method since it can damage the motor.

I've had to do this in foreign lands that only had access to metric tools and brute force with a good puller was the only way to get it off. It will scratch the shaft, but as long as there aren't any burrs, a quick polish with a scotch pad and it's no worse for the wear.

If the puller fails to do it...time to get the whizzer wheel out and cut it off.

-B

[rb99]

I have the correct wrench, just on there, probably with blue loctite.

I will use the pullers I guess...

Thank you Brady.

[rb99]

For anyone in the same situation I found a Torx ratchet tip that was ever so slightly larger. I carefully positioned it on the allan grub screw. I tapped it with a hammer a couple of times, and used the ratchet to remove the stubborn grub.

[coryatjohn]

Often, an impact wrench will coax out a stuck bolt where human strength would just strip it. Something about the way it hammers frees stuck bolts.

[Rob Gunn]

Try Heat, candle wax, the correct size wrench. If that doesn't work then you will have to drill it out, or grind it like Brady said. You can always drill and tap a new cross screws.

[harryball]

Sounds like the op solved the problem. When I ran into a similar problem before, I used an "easy out" extractor and it worked like a champ.