One if the threads on the hub is nakered now. can i get away with using just one screw; as the disc's still held on by the wheel nuts etc?

Absolutely fine.

 

To help stop this and other similar problems in the future, I usually put a smear of copper grease on the bolt thread. Its much more likely to come out when you want it to.

 

yea will be grand, theyre only really there to hold the disc against the hub, just to stop the disc from slipping out of place

 

Yep just fine. I hate those damn screws, why oh why did they make them out of lead?

 

cheers guys! ill do that then. yea they're crap those bloody screws!! got the 2 off the other side with a philips head drive that fits into a drill. put some large mole grips around it, and used it to remove the screws. worked a treat! shame i thought bout that after doing the side i nakered.lol!! anyone know the thread and length of those? M6x?? Thanks again!!

 

I find an impact driver soon sorts these out!! :broon:

Cheers
Dave

 

Andy,

Don't confuse an Impact driver with an Impact wrench.
Most Impact drivers are Hand-matic, not Air-matic.
Impact wrenches are the tools you see tyre fitters abusing your wheel nuts with.

They look like a heavy metal screwdriver, with usually a 3/8" square bit to which you the relevant screwdriver end. Then you put it in the offending screw, and hit it with a hammer!! The driver has an internal cam that, along with the shock of the hammer blow, just moves the screw a little, so you can get a proper screwdriver in.

I've had one since the early 70's when I was working on Jap motorbikes thet were put together with star screws that reacted with the casing material and corroded badly.


I agree with RevorTD - put a smear of Copper Grease on the thread and importantly, on the taper of the screw - in these hub screws, it's the taper that "grabs" rather than the thread corroding in.

Mike

 

heavy metal screwdriver

Lol.. heavy metal screwdriver :rocker:

 

You can always drill through the screw and re-tap the thread to M6 btw, if you want to replace it.

Brian.

 

You can get electric impact drivers too I believe.

 

No, that would be a wrench.

The whole idea here is that the thrust from the hammer gets the toolbit firmly into the screw so it will not slip, therefor you need a hammer to provide the inward thrust.

They cost like 20£ for a nice one, and they have exchangeable bits, its the right tool for the job.

Jon

 

No. You're not understanding here. The point of a hammer-type impact driver is that you're hammering the tool ON to the fastener in question.

An electric (or air driven) impact wrench can only be held onto the fastener by hand force, so for difficult crosshead screws, you'll just chew the head.

As has been said before, you *cannot* undo the screws that hold small japanese bike engines together without an impact driver..

Brian.

 

How do you think a hammer drill works, or a pneumatic drill?

12v impact wrenches are also recommended essential kit for Chinese scooter riders.. to remove the variator (which you can't do without an impact tool).

I see potentially what you mean about the screws but given the first action is a impact/twist whether you use a hammer type or wrench either should work.

 

I'm sorry but I agree with Brian. They do not work in the same way. The hammer type impact driver as they should be called (not the same as an impact wrench) works on the principle of the downward force generated by the hammer forcing the bit of the driver into the fastener and then the internal cam uses some of that force to provide a bit of twist to free it.

Impact wrenches don't work on a hammer principle. They work on the principle of a weight spun at high speed which is suddenly stopped to provide a jolt to the fastener. No downward force is applied.

Hammer drills work in another way to either.