MT-03 660 - Drive Sprocket Removal

[Bourneriver]

Hi Everyone

I'm Richard a new member from the UK

Trying to remove the drive sprocket on my 2011 MT-03 660.

Bent back the tabs on the tab washer but I can't seem to budge the nut.

Don't have a pneumatic impact gun so using a 2 ft long bar, person on bike, both brakes on.

Still no-go so I'm wondering if its a left hand thread or there's a trick I'm missing?

Don't want to use heat as I have an O-Ring chain, plus not sure if there is a nearby output shaft seal or similar.

Any suggestions gratefully received.

Richard

 

[Snakebite68]

There should be enough of the thread sticking out for you to see whether it's a left or right hand thread.

A picture of the offending item would help here...

[Bourneriver]

Hello

Thanks for your reply.

Picture attached. No protruding thread but looking at You Tube videos for other bikes (inc. XT660) they are all right-hand threads, so suspect mine is too,

I think now that its just very tight.

Asking around a friend has said he had similar when a bike shop fitted his sprocket with a pneumatic impact gun - suggests over-torqueing which is a worry. I didn't own the bike when my sprocket was fitted so can't be sure.

May have to talk to my friendly MOT garage and see if they can get it off. It's that or drill the nut and split it 

[Snakebite68]

Where in the UK are you?
Might be someone close with an impact gun...

[Bourneriver]

I'm in Bournemouth BH4 postcode

[NE0]

another effective method is a hammer and a sharp chisel to knock it around and unthread it. Its a bit of an acquired skill, but once you get it going its comes off easily.

 

Don't hit it on one facet of the nut, vary it.

[Snakebite68]

7 hours ago, Bourneriver said:

I'm in Bournemouth BH4 postcode

Yeah, too far away for me, I'm West Yorkshire lol.

Ok, a 2' bar isn't as long as you imagine (I use a 3' breaker bar on mine).
I assume you're trying to turn it by hand, your legs are stronger.

I would try one of these:

 

Do the same as you were with someone on the bike and the brakes.

 

1/ Soak the nut in penetrating oil.

Put the bar on so it's horizontal and put your foot on it.
Making sure it's not gonna come off the nut, start taking up the flex in the bar.
Once there, bounce slightly. If you're using a proper breaker bar, I'd expect to see a very stiff nut flex a 2' bar a couple of inches.

One of these bounces should crack off the nut.

 

2/ Soak the nut in penetrating oil.

Put the bar on so it's horizontal and put your foot on it.

Making sure it's not gonna come off the nut, start taking up the flex in the bar.
Once there, get a third person to strike the back of the socket with a hammer (firm flat blows (doesn't have to be really hard or anything)).

This will basically act like an impact gun.

[Bourneriver]

Thanks for the replies.

I have been trying penetrating oil but it is getting it into where the actual male and female threads are in contact.

Also breaker bar is an old school Norbar torque wrench which doesn't flex, well not at these sort of torques.

Access is tricky for anything too brutal, not wanting to damage the bike when it does let go and tools move about a bit. Also I seem to be at the maximum the rear brake can apply when preventing the wheel from turning via the chain which is of course straining those components too.

I'm going to call in at the MOT garage over the weekend and see what they can do.

Thanks again for all your suggestions.

Richard

[drewpy]

I would use a heat gun as there may be thread lock on there and should help undo.

I've had to jump on my breaker bar in the past