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Location:
goldy coast
Registered:
September 2004
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keep snaping balancer key?
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Sat, 15 January 2005 00:23
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Hey about 4 months ago i snapped the key that holds the harmonic balance and crank shaft timing gear in my rwd 4age, and last night it did it again!  , what would be the reason for this? could there be to much play in the key way,or my cranck shaft needs to be balanced or something?
mike
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Location:
Brisbane
Registered:
February 2003
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Re: keep snaping balancer key?
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Sat, 15 January 2005 00:36
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too muich play in keyway and/or key is wrong size
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Location:
goldy coast
Registered:
September 2004
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Re: keep snaping balancer key?
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Sat, 15 January 2005 06:10
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yeh thought so ill get it sorted anyways just i hope it doesnt do it again because its a serious pain in the dot
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Location:
Melbourne
Registered:
January 2003
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Re: keep snaping balancer key?
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Sat, 15 January 2005 06:21
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Harmonic distortion caused by crankshaft flex ? what is it happening at 11.000 rpm , sounds like the pulley keyway might be shagged out , or its not going to full distance on the crank . Does the pulley line up correctly when installed ?
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Location:
goldy coast
Registered:
September 2004
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Re: keep snaping balancer key?
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Sat, 15 January 2005 07:05
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| improvedae86 wrote on Sat, 15 January 2005 17:21 |
Harmonic distortion caused by crankshaft flex ? what is it happening at 11.000 rpm , sounds like the pulley keyway might be shagged out , or its not going to full distance on the crank . Does the pulley line up correctly when installed ?
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no 1st time it happend was at 6000 rpm this time was at max 4000 rpm,also the pulley lines up how it should so i dont think it is that. Another thing i notice when the engine was running before it broke at a 850-1000rpm idle the balancer had a slight wobble nothing crazy but when rev'd higher it would straighten up, would this slight wobble slowly break down the key and balancer?
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Location:
tallahassee FL usOFa
Registered:
May 2002
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Re: keep snaping balancer key?
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Mon, 17 January 2005 03:49
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sure, any wobble is going to load it more then something that is running smooth & true.
how long was before the first time????? how long after it was installed, for a timing belt or something?
the key only does and is only capable of a small percentage of the holding power necessary, so it needs torque & good surfaces. it has to be installed right.
i think the thing came loose at first because of a poor install, and the 2nd time because the surface of the hub and the timming gear/pully weren't smooth & flat. a right hand thread & rough surfaces & low torque arent going to last long.
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Location:
goldy coast
Registered:
September 2004
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Re: keep snaping balancer key?
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Mon, 17 January 2005 08:45
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i half pulled it apart yesterday to have a better look and the actual key is still good only abit worped im guessin from when the balancer snapped off, after pulling another harmonic balncer n holder bolt straight off another engine ive notice that the bolt is different to the 1st two that have stuffed up i know the last bolt i used was off a 7me..? but was exacly the same as the bolt that was in there.
so im guessing that the bolt was to fault this time maybe thats y the head snaped off it and the stud is still inside my crank shaft 
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Toymods Board Member
I supported Toymods
Location:
Turramurra, Sydney.
Registered:
May 2002
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Location:
goldy coast
Registered:
September 2004
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Re: keep snaping balancer key?
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Mon, 17 January 2005 10:37
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oh k so the origonal bolt the 1 piece was no good? the one i have now is the 2 piece, so this should help?
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Toymods Board Member
I supported Toymods
Location:
Turramurra, Sydney.
Registered:
May 2002
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Re: keep snaping balancer key?
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Mon, 17 January 2005 22:52
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Yep, that's what I've heard.
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Location:
goldy coast
Registered:
September 2004
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Re: keep snaping balancer key?
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Tue, 18 January 2005 12:25
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oh ok should be all good then this time....  on another note would anyone be able to give me a rough price on some nevo balancers for a 4age i was thinking while its off i might aswell throw on a better one 
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Location:
tas
Registered:
June 2002
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Re: keep snaping balancer key?
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Tue, 18 January 2005 13:16
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I had a simualr problem. My pulley was wobbeling quite bad when i got the car, when i took it off to inspect, the key was sheared in half, the keyway in the crank itself was worn to the point of the keyway unable to slot in straight. Buaght a new crank pulley and made my own key out of case hardened steel and made sure it would stay in place. Also tightened the it RIGHT up to specs, obviously the previous person to remove it did not tighten it up enough.
Also abit of a design flaw in my opinion is having the thread the wrong way around, so instead of that big bolt tightening with the engine spinning, it has the opposite effect of working it's way loose.
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Location:
Adelaide
Registered:
December 2004
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Re: keep snaping balancer key?
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Wed, 19 January 2005 02:14
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If the keyway has broken it is possible that the pulley has worn down the crank snout by spinning on it and therefore will be too loose.
The crank pulley should have a reasonably tight fit with the crank and the key.
I would suggest that if you change it you should pick up new keys and a new crank bold from toyota. Itll only cost you $10 or so.
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Location:
goldy coast
Registered:
September 2004
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Re: keep snaping balancer key?
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Wed, 19 January 2005 10:50
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ok my next question how would i go about extracting the balancer bolt stud out of my crank shaft? i was thinking an easy out but its impossible to drill through the stud
mike
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