Gearbox shell problems, drilliing a good idea or not?

Soberts

I have been trying to stick a new set of high speed gears into my kwa gearbox. No matter what combination of shims i use, i cannot get it right. The new gears are very slightly thicker than the stock KWA gears and are just too tight a fit.

I noticed that the bearings are not fully sunk into the shell and stick out about 0.75mm into the inside. I was wondering if i was to drill into the shell using a drill bit as shown below would i weaken the shell or would it be ok? The drilling would be to sink the bearings further into the shell, giving more clearance for the gears and shims

THE MINDER

Soberts wrote: »

I have been trying to stick a new set of high speed gears into my kwa gearbox. No matter what combination of shims i use, i cannot get it right. The new gears are very slightly thicker than the stock KWA gears and are just too tight a fit.

I noticed that the bearings are not fully sunk into the shell and stick out about 0.75mm into the inside. I was wondering if i was to drill into the shell using a drill bit as shown below would i weaken the shell or would it be ok? The drilling would be to sink the bearings further into the shell, giving more clearance for the gears and shims

That bit is for drilling wood Steve!

Soberts

THE MINDER wrote: »

That bit is for drilling wood Steve!

Haha!! Yeah i know but the gearbox shell is only pot metal so its soft enough, it also means that i dont go any deeper than i need to because the drill bit has no taper on it.

I dont know any other options really!

Leftyflip

Before you go drilling the shell or anything - try a different set of bearings or bushings. I know I have some original KWA bearings knocking about, or are you purposely staying away from them?

Soberts

Leftyflip wrote: »

Before you go drilling the shell or anything - try a different set of bearings or bushings. I know I have some original KWA bearings knocking about, or are you purposely staying away from them?

No not staying away from them at all, just trying to get the new gears to work! All the bearings are the same size in this gearbox, think it might be the 2gx one so it uses all 9s instead of two 8's and one 9mm bearing. Would you happen to have a set of 9mm bushings/ bearings you would let go of, i can buy them off you when im getting the sector chips?

I will have to double check the size tho, but i know they are all the same size

Leftyflip

Soberts wrote: »

No not staying away from them at all, just trying to get the new gears to work! All the bearings are the same size in this gearbox, think it might be the 2gx one so it uses all 9s instead of two 8's and one 9mm bearing. Would you happen to have a set of 9mm bushings/ bearings you would let go of, i can buy them off you when im getting the sector chips?

I will have to double check the size tho, but i know they are all the same size

I have some, but I think I left them in AWOL with some of my other bits - I'll let you know later mate.

cascar

i got the same problem before, when talked to Chris from MIA and he said the stock KWA gears dont require shims. THats why my gears werent fit.

F.U.B.A.R

so what there self shimming?

Soberts

The stock gears have what look like shims on them but they are permanently attached. I cannot get them off!

I think i might just leave the gearbox with the stock gears for as long as i can but i really want those high speed gears in there at the same time

Leftyflip

KWA gears are pre shimmed - in most cases they're bang on and there's no movement, occasionally there is a tiny amount but nothing serious. the gearbox shells are designed for those gears, or vice versa.

Soberts

I bought that drill bit pictured above and it worked perfectly! I have the high speed gears (13:1) in now and im pleased with the result (just incase anyone was interested or had the same problem!)