Gearbox

[brooksy]

Im sure this has been spoken about before but I can't find it,I have just started building my 210 and the gearbox. When I turn the spur it doesn't run very free. If I remove one or both of the gold shims from both sides of the diff will this help?.

Phill

[TonyM]

I think there is a little tolerance in the manufacture of the gearbox. I've built two, and one needed bronze shims either side, while the other needed none. I think it's just a matter of shimming, or not, until you feel no side play.

[brooksy]

Cheers Tony, I'll have a look tonight

[s22jgs]

its likely you may have overtightened the screws holding the caseing together.

There is a very fine line between it being done up and over tight.

back them off half a turn but not enough that the casing comes apart and then test it

[brooksy]

Hi Steve. Definately not over tightened the screws. If I back the screws off enough for the gears to run free and how i would like them,they're way too loose.
I'll give the shim idea a try tonight and hopefully that's all it is.

Cheers for the reply though.

[Tweaky]

Hi, last time I had my gearbox apart I found the spur/slipper shaft pinching up in the housings when I tightened the motor plate. All the original clearance had gone. I.e. try wagling the spur slipper assembly in and out of the housing when assembled. There should be a little bit of axial play. I had to put 3x0.8mm thick spacers between the 3 pronged yokey thing and the gearbox housing to stop it pinching when tightening the motor mount screws. I put it down to the plastics just giving a little over time, surprised it happened on a new one!
Hopes this makes sense, I'll try and take a picture later.
Paul

[TonyM]

I found that two of the long screws that fix the gearbox to the motor plate were just a bit too long and protruded through the plate, to the extent that when fully tightened the slipper plate was rubbing on the screw thread. After adding another washer under the screw head all OK.

[Tweaky]

Originally Posted by TonyM

I found that two of the long screws that fix the gearbox to the motor plate were just a bit too long and protruded through the plate, to the extent that when fully tightened the slipper plate was rubbing on the screw thread. After adding another washer under the screw head all OK.

Yes that's the first sign that the carrier and gearbox is squashing, if you check the axial play on that slipper assy, you'll notice there won't be any, or when you turn the spur it will feel notchy and stiff. When that happens, get shimming.

Its a great car, but plastic material selection on a couple of items could do with improving.

[brooksy]

Tried the diff and theres just the smallest of movement so I tried your idea tweaky, put thin shims between the gearbox and the pastic spacer and it's spot on now

[Jason A]

When I last rebuilt my gear box I defornatly found that if the gearbox screws are ever so slightly to tight it was causing the gearbox to lock up a bit. The thing is that plastic does give and with only ever so slight backing off of couple screws my gearbox was silky smooth again.