Noisy gearbox with SHS hi-speed

[Clone1B]

Hi guys,

I've recently put SHS 13:1 gears and an element hi-torque motor in my ICS m4, was my first time shimming a gearbox but I think I did an okay job as everything was rotating freely and the pinion met the bevel gear at a good angle, only a slight axle movement on the spur gear. One thing I've noticed is that with this setup the gearbox sounds pretty grindy but I've gone through and triple checked to make sure nothings in contact. Put a couple hundred rounds through it and opened it up to check for wear and couldn't see a single bit on the gears or the gearbox.

Is this just what high speed gears sound like?

[sparrowhawk]

Re: Noisy gearbox with SHS hi-speed

did you try adjusting your motor height, every so often lower or raise it,and check the sound

[seansamurai1]

Re: Noisy gearbox with SHS hi-speed

That above, could also be the motor making a grindy noise, I've found Chinese motors to be fairly noisy.
When shimming did you start with the bevel gear? If so did you get that as low as possible? If it sits too high it tends to make more noise when the motor engages, my SHS gears are fairly quiet in mine.

[Clone1B]

Re: Noisy gearbox with SHS hi-speed

I've got the motor height good. The height didn't seem to make much of a difference to the grindy noise, I could just hear the pinion gear engaging at a different angle.

When shimming I found that if I set the bevel gear almost flush with the gearbox the pinion gear wouldn't engage it properly and it slightly scuffed.
It might just be the motor, its a lot torqier than my ICS Turbo 3000.

[danhc]

Re: Noisy gearbox with SHS hi-speed

did you lube it?

[Clone1B]

Re: Noisy gearbox with SHS hi-speed

Lubed it enough. Nice gunky grey grease on the moving contact parts, not enough to splatter though.

[sj_asc]

Re: Noisy gearbox with SHS hi-speed

Shouldn't be too loud at all, As pointed out, the bevel gear shimming is essential.
Also essential the gears are shimmed with the lower half screwed shut on each adjustment, it makes a big difference.
Although it's more difficult with the ICS, the sector gear position is essential to tappet operation.

[danhc]

Re: Noisy gearbox with SHS hi-speed

maby try breaking the motor in by running it on a couple of double a batteries in distilled water?