Yet Another Gear Issue.

[LazzurusMan]

So, I've installed my gears, shimmed them, adjusted motor height and tested the whole thing without the piston and cylinder.

It sounds horrible.

I open her up, and this is what the bevel gear looks like. Is this shimmed too close to the motor? Motor height too high or low?

Please don't tell me I've ruined it and need to buy another set of gears.

View attachment 76076

View attachment 76077

 

[Pewpewpetie]

I would say the bevel is sitting to low for the pinion, therefore not meshing adequately. If you were confident with you shimming and motor alignment the maybe something interfering with angle of pinion. I've worked on some guns where I've tested with gb closed and pistol grip on, sounds fine. Then I put the whole gun back together and the lower reciever pushes the grip out of alignment. I believe there is a video of you tube demonstrating this. 

 

[LazzurusMan]

Yeah, my shimming was perfect.......to the gearbox and other gears. Pinion to bevel shimming was awful. I've since re shimmed and she sounds a little better now, though still  a little loud. I'll be posting a video in a separate thread today.

 

[Sneaky]

Question: when shimming do you take everything out of the gearbox shell, then shim on gear - close the box, spin it with you finger.  Repeat for each gear.  It is time consuming, but that’s the most accurate way to spot out any issues.

 

[Rogerborg]

Yes, that's what I do.  Take everything out that can touch the gears, including the cut off lever and anti-reversal latch.  If you've taken the time to open the gearbox, you might as well take the time to do it right.