Timing sprocket

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scouttster
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My tercel:: 1984 Tercel Hatchback
Location: SW Florida

Timing sprocket

Post by scouttster »

You guys are positive the timing sprocket and crank shaft are 2 seperate parts? I have used heat and PB blaster, and its a toughy.. Oh, that key doesn't pull out, does it? Its a machined key as a part of the crank shaft, correct?
Thanks
Terkey Hatchback
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sdoan
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My tercel:: 1983 Tercel 4wd DLX 2nd owner (sold), 1984 SR5 3rd owner (sold), 1984 with 4A engine and factory sunroof SR5 3rd owner.
Location: Bellingham, WA

Re: Timing sprocket

Post by sdoan »

The crank, sprocket and key are all separate parts. I would heat the sprocket and try to keep the crank cool to let expansion of the sprocket work for you. It doesn't have to be very hot. You don't have much to pry against and I don't think there is enough room to get puller jaws behind it so prying lightly with screw drivers on either side might walk it off. Let us know how it goes.

If you've used a lot of heat you will probably want to replace the oil seal behind the sprocket and it's easy to replace the whole oil pump then too. Napa had Aisin pumps last time I checked.
scouttster
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Posts: 115
Joined: Thu Jan 01, 2009 6:14 pm
My tercel:: 1984 Tercel Hatchback
Location: SW Florida

Re: Timing sprocket

Post by scouttster »

yea, the oil seal is shot thats why I'm taking it off - to replace the gaskets and seals, etc. It was rusted on, but I finially got it off. I used the screw-drivers enough to get it so that I could slip the pulley jaws behind and still she was tough. I had to walk it out the whole way.. Any advice on getting that key out? That seems to be rusted in there..
Thanks for the tip. I posted a pic of the process so others could maybe learn from it..
Image
Terkey Hatchback
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splatterdog
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Re: Timing sprocket

Post by splatterdog »

Just leave they key for now. Clean all the rust off the crank and sprocket and it should be a slip fit. Just don't be too aggressive. Dremel/wire wheel is my preferred method. I also use the thinnest film possible of anti seize on reassembly. Wipe up any excess so as not to get any on the belt.

Don't forget the cam seal too.....
scouttster
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Posts: 115
Joined: Thu Jan 01, 2009 6:14 pm
My tercel:: 1984 Tercel Hatchback
Location: SW Florida

Re: Timing sprocket

Post by scouttster »

Thanks for the reply. Forward part of the key is all de-formed and eroded from the harmonic pulley being loose. Crank screw was loose and as a result a back and fourth wiggle or play occurred that did a number on the pulley and the key. I posted a pic of the pulley a few posts back. Any tips on how to get it out and if I do get it out whats procedure for getting a new one back in? Slip fit in? Pressed in with a c-clamp maybe?
Terkey Hatchback
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sdoan
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My tercel:: 1983 Tercel 4wd DLX 2nd owner (sold), 1984 SR5 3rd owner (sold), 1984 with 4A engine and factory sunroof SR5 3rd owner.
Location: Bellingham, WA

Re: Timing sprocket

Post by sdoan »

The key should be a slip fit - but with no clearance so dirt and deformation can make it tight. If you take it out get the keyway clean.

You can leave the key in and dress it with a file (don't nick the crank) - it doesn't have to be perfect. Or I've had good luck driving keys out using a hard straight blade screw driver as a drift. Lay the blade flat across the keyway in line with the crank and drive the key towards the back of the keyway. The key often lifts up at the front as it comes out. The problem with this is that if the key is really stuck you may just end up with a more mangled key. Keep in mind that the key is made of soft steel so can easily deform as you hammer on it.
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splatterdog
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Re: Timing sprocket

Post by splatterdog »

If it's mangled it's gotta go. Tap it out as sdoan said. A small sharp chisel works well too.
scouttster
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Joined: Thu Jan 01, 2009 6:14 pm
My tercel:: 1984 Tercel Hatchback
Location: SW Florida

Re: Timing sprocket

Post by scouttster »

Just wanted to comment on the removal of the Key for others to learn.
No hammer or screw-driver as a drift to remove is necessary.
It was fairly easy to remove.

Just grab at it with a pair of vice-grips, then position a small piece of wood between the vice grips and the crank for a lever action ( fulcrum ) and with light downward pressure it lifts right out easily. New Keys are about 28 cents at Napa
Terkey Hatchback
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