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Location:
Armidale
Registered:
January 2003
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Bizzare 7MGTE balancer 'problem'
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Thu, 16 September 2004 11:12
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This is a little weird - anyone else met this before?
The harmonic balancer on the 7M is a pretty deep unit, with the retaining nut seated deep inside a bit of a 'tunnel' through the centre of it.
Now, 'lining' this tunnel is a metal sleeve, which seems to have become detached. You can hear a bit of a rattle at idle, sometimes when driving (esp. on deceleration), when starting (it had us looking for a non-disengaging starter for a while...) and very noticeably for a second or two on shut-down.
If I stick my finger in there, I can move it around a fair bit, but it doesn't want to come out entirely. Apart from the noises, it doesn't seem to be a major drama, and I can't be bothered fixing it before the 1JZ goes in.
But the question is - is it likely to lead to catastrophic failure, or am I right in thinking it will probably last another couple of thousand km?
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Location:
Adelaide, SA
Registered:
May 2002
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Re: Bizzare 7MGTE balancer 'problem'
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Fri, 17 September 2004 00:43
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It sounds like your crankpulley is loose. There's a woodruff key the fits in a keyway in the crank and lines up with a groove/slot carved in the pully. It gets loose, rattles pretty much as you described and gets worse and worse and louder the longer you leave it. Eventually it'll wear the keyway in the crank and slot in the crank pulley out. If it has a metal sleeve in there already it sounds like sone-one has tried to fix it previously.
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Location:
Armidale
Registered:
January 2003
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Re: Bizzare 7MGTE balancer 'problem'
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Fri, 17 September 2004 03:21
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Hmmm ... possibly. Although the pulley (balancer) itself seems perfectly secure. And we've owned the car since new and AFAIK there has never been anything done to it previously.
But I'll have a peek at the keyway and see what I can find ...
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Location:
Lost in the K hole
Registered:
May 2002
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Re: Bizzare 7MGTE balancer 'problem'
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Fri, 17 September 2004 03:39
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take off ALL the belts... remove all tension from the pulley/ballancer, and see if its mobile...
the balancer is made in two sections... the centre section which attaches to the crank, a rubber damper middle part, and the outer ring which includes the drive channels.
it would be VERY hard for the inner part to be loose and not have the outer part loose also... ie - the whole pulley is loose - this is a major problem if youve been driving for a while as it will destroy the engaging section of the crank, and the pulley will never retighten.
so yeah, de-tension the pulley, see if its mobile, get a socket onto the pulley nut, see if its loose.
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Location:
Armidale
Registered:
January 2003
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Re: Bizzare 7MGTE balancer 'problem'
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Fri, 17 September 2004 13:38
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I have already taken all the belts off - that's how I pinpointed the noise in the first place  (I started searching for what I thought might be a dodgy idler bearing).
The whole balancer is rock solid, as is the nut that holds it on. That's what makes it so bizarre 
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Location:
melb
Registered:
June 2003
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Re: Bizzare 7MGTE balancer 'problem'
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Fri, 17 September 2004 15:19
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Double counter weight 7M s have a round peice of steel, rubber bonded in the centre of the crank pulley with a 50 mm hole in the middle for the bolt to go thru, sounds like its buggered and thats your noise.
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Location:
Armidale
Registered:
January 2003
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Re: Bizzare 7MGTE balancer 'problem'
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Sun, 19 September 2004 14:12
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Cambelt, that sounds more like the problem.
Any idea what the implications might be for running like this for a while? I have a 1JZ for it gathering dust in the shed, but things are conspiring to stop me fitting it for now ... the old 7M will have to do for a few more weeks.
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