Miata Timing belt HELP! (woodriff key): Grassroots Motorsports forum: Grassroots Motorsports Magazine

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Aug. 29, 2010 2:49 p.m. Apexcarver UltraDork

I bought this car less then a week ago. The motor that is in it is a junkyard motor (100k miles) that was just installed last week by the PO (who is a friend). The motor still has a warrenty, so that is an option, but I just need to balance my options.

The motor had a leaky water pump, so I decided to go ahead and do the timing belt and water pump maintenice. Well, during teardown this is what I find.

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There is still a piece of the key in the crank nose. The motor is a 1996 1.8L (so a big nose)

If I can get the broken piece out should I just put a new key in and go with it?

Does it need a locktite fix similar to the short noses?

Use the warranty and get another motor? (motor ran well the last few days)

alternate links to larger images

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Aug. 29, 2010 3:37 p.m. Tyler H Dork

I would get a new key, bolt, timing gear and slap it together with some locktite 660.
Aug. 30, 2010 12:22 p.m. Apexcarver UltraDork

Went ahead and ordered the key bolt and timing gear. Hopefully it goes back together with no more surprises.

Where is a good place to get that loctite product?
Aug. 30, 2010 7:29 p.m. deadmeat New Reader

I would try calling around to Napa's and other such stores. Maybe Ace Hardware or similar stores.

-meaty
Sept. 5, 2010 3:08 p.m. Apexcarver UltraDork

Ok, I cant get the timing gear off of the crank nose, anybody have a tip on that?

The reserve plan seems to be to drill some holes in it, tap and thread some screws in and see about a slide hammer for that. (would have to buy a slide hammer and other tools)

All the manual has to say is insert into screw holes on it.. well, look at the pis above, no screw holes.

I have a new gear for it, so damage to it isnt really a problem. I need to get it off as there IS a piece of woodriff key broken in there.
Sept. 5, 2010 4:01 p.m. Javelin UltraDork

PB Blaster or use the drill/screw/slide hammer.
Sept. 5, 2010 4:08 p.m. Apexcarver UltraDork

looking like I am going to have to drill... I did PB it and tried what prying I was able to do without messing up whats behind it to no success.

as well as some heating with a propane torch. I might be able to get more serious with the heat. (more time with the propane, or I do have MAPP gas)
Sept. 5, 2010 7:43 p.m. pigeon Dork

I think you're rapidly approaching the point where it would make more sense to warranty exchange the motor.
Sept. 5, 2010 8:59 p.m. Jensenman MegaDork

I'm thinking you have voided the boneyard warranty. So it's time to forge ahead. Put down the torch! That will melt the timing cover seal. Get a muffler cutter or similar, turn the crank with the key pointing upward and grind a slot in the gear in line with the keyway. That way you don't risk messing up the crank. (You will, of course, need a new crank gear which you say you already have on order.) Grind a slot as deep into the gear as you can, then put a blunt chisel in the slot you made and smack it with a hammer. You are trying to split (crack) the gear. If you can't get a muffler cutter, then drill a series of holes in line with the crank keyway (same general idea).

Once split, the gear should slide off pretty easy. Use Scotchbrite or emery cloth to polish off the crud on the crank nose then install a new gear and key. I'd use some anti seize or similar to prevent a reocurrence.
Sept. 5, 2010 9:09 p.m. Apexcarver UltraDork

If all I have done is disassembly for the timing gear job and discovered the broken parts do you think it voids the warranty?

I really am starting to question forging ahead with this vs berkeley it and diving into an engine swap. I would really rather get it apart I think. (I have all the parts for it on hand)

So you think go at it with (in my tool assortment I am thinking a cutting wheel on my die grinder) and try to split the gear is the best way forward?

This is frustrating as hell.. I bought this car last week and got 3 days of driving it and now this
Sept. 5, 2010 9:23 p.m. deadmeat New Reader

Had a similar problem with a friends. The woodruff key broke, and piece actually got in between the crank nose, and the timing belt cog.

We went ahead and used a torch to heat the metal, but basically we started with small screw drivers, driving them behind the gear between the motor on each side, kind of working it off while heating the gear to try and expand it/loosen it. As it came out, we used bigger screw drivers and eventually big wedges to get it out.

It took a while, but it ended up working.
Sept. 6, 2010 7:48 a.m. Jensenman MegaDork

Apexcarver wrote:

If all I have done is disassembly for the timing gear job and discovered the broken parts do you think it voids the warranty?

That's ultimately between you and the supplier. It's corrosion damage, which has always been something of a gray area. I'm thinking they may have wanted a chance to swap it out before it got all disassembled. But there is another angle.

Think of it this way: you have an engine which you know runs well, but needs a crank gear. Once that repair is done, you now have a good running engine with a new water pump, timing belt etc. Are you willing to swap this motor out for an unknown quantity? The next one might not run as good and could have other issues worse than the one you face now.

It's a helluva lot more work to swap engines than to swap crank gears, even if said gear is seized.
Sept. 6, 2010 8:08 a.m. purplepeopleeater New Reader

Joe Do you have access to a gear puller? Could make life easier.
Sept. 6, 2010 9:49 a.m. Apexcarver UltraDork

I have a 2 armed gear puller and I was thinking in bed last night about cutting into the sides of the cog to create something for it to grasp (no room for the teeth to get behind the gear) and putting the old bolt on there to provide something for the center screw to push on. (added bonus, this dosent require bad loads on the bearings, its all on the crank, but shouldnt damage it)

Gonna have to try that, only thing is that my cutting wheel is 45min away at my friends CP camaro build, so it might have to wait for next weekend.

Jensen, you defiantly have a point there. It is time to forge ahead.

ARRG! I just want to drive the blasted thing!