Mechanics 101

[rhysk]

I am removing the timing belt gear from the crankshaft. I have a puller which has moved it half way off, but from there it won't budge. I am going to apply a bit of heat using a propane torch.

Question: Do I have to replace the gear if I heat it up?

[sabretooth]

It will return to its normal size when it cools back down, so nope.

Wht are you removing? The crank pulley?

[rhysk]

I got the crank pulley off easily enough. The gear (for the timing belt) won't move. I'm doing the oil seal on the crank, which is behind the gear. The gear has two M4 bolt holes, so I can use a puller, but I keep breaking the bolts.

I just chipped the rim of the gear trying to lever it off, so I will need a new one anyway (they are apparently quite cheap - US$20). But the f....king thing is still on the engine.

This is on the NA.

[sabretooth]

Definitely find a pulley puller. My gear was stuck on because a little rust formed in the join. I used some engine building tool (I'd modded to become a pulley puller - I'll find out the name of it when a mate comes back online) and it eventually worked the gear off. You should be able to find one to hook around the rear rim of the gear - it needs to be one which doesn't just grip the rim, but also the back of the gear.

[ndragun]

i use a large flat head screwdriver and swear a lot.
Typically i find the more socially unacceptable the swear word - the easier it is. Or if you don't have a particularly offensive swear word at your disposal, increase the volume of whichever words you DO have access to.

[rhysk]

You should be able to find one to hook around the rear rim of the gear - it needs to be one which doesn't just grip the rim, but also the back of the gear.

Cool, I have one of these jaw type pullers, but it is the wrong size and doesn't quite line up correctly. Do you have one? If you have a moment this week, could I come round and have a look at it so I know what size I need?

The puller I have been using so far is the type that bolts up to the front of the gear. That, and a screwdriver, along with the appropriate language for removing pulleys.

[kitkat]

when i went to get the gear off i tried for ages trying to just pull it off or lever it off with screw drivers and what not, then i gave it a wiggle left and right by hand and it came straight off.

Also the timing gear and seals are under $50 from mazda.

[sabretooth]

I'll get a mate to photograph what it looks like - the tool I used is at his place at the moment (as it's his). I think it's actually meant for piston rings or something like that. He bent it doing something and it became useless. So when I was doing my clutch at his place I grabbed it and turned it into a pulley puller. You can find them in most decent hardware stores anyway.

[rhysk]

Thanks mate. You're talking about this type, right?


kitkat - cheers, i'll try wiggling it but I don't like my chances.

[sabretooth]

Yep that's it. Very handy tools to have.

[sabretooth]

OK, the tool I used to remove my stuck timing belt gear was actually a valve spring compressor. The only reason I was able to use it as a pulley/gear puller was because he bent the tool using it I think it was a cheapie.

[rhysk]

Cool. I still haven't picked up a new puller, but I plan to this afternoon. Last night I went medieval on it with a screwdriver and propane, and managed to get it from 1/2 off to 3/4 off, before I ran out of leverage

[irwin83r]

dude

if your replacing it, drill and tap two m10 holes in the gear buy some high tensile threaded bar or bolts and use them as jacking holes.

also make sure you emery the shaft clean it and let it soak in some wd40 for awhile (hours) or some penetrene (or what ever its called).

then heat till it glows (well not quiet) once its over 100degs (will boil water on contact or your spit ) it should of expanded afew thou and then jack it of with the threaded bar/bolts. you'll need a backing plate or a piece of plate with two m10 clearance holes and a packer thats slightly smaller than the shaft your pulling it off OR tap a third hole in the plate and put a big bastard bolt through that to push on the shaft.

that is if you have acess to taps drills plate and threaded bar

in any case if you heat it i would be tempted to cool the shaft imediatly after wards with water or oil in a squirty bottle so the heat dosnt transfer up the shaft too much, it probably wouldnt be a drama, but if you find your getting the shaft as hot as the gear then both will be growing together
and if you heat the shaft too much you may change its properties..

just afew things to ponder, if you can try this without having to buy something would be worth doing but the puller is deffinatly a handy tool. just dont tooo cheap, cheap but good but cheap cheap and they flop around an slip off things and arnt hardened properly.

[irwin83r]

or is the gear hardened too much to drill just realised drilling and tapping may not be an option then

[rhysk]

I thought about that - one of my pullers uses M8 bolts - but access is pretty limited for a drill.

Anyway, I got a puller the correct size, and 2 minutes later it was off.
I actually already had a few pullers, but none that were suitable.

Thanks to all