View Full Version : 250sx cam chain tensioner bolt stuck?
tri again
05-15-2012, 07:01 PM
External cam chain tensioner with 2 bolts holding it in.
One bolt popped loose like it should and the other one really wants to simply twist off inside the case.
so I walked away from it.
Heat? Will heat melt anything inside the tensioner?
Thanks
Dirtcrasher
05-15-2012, 07:11 PM
I'm lost with the SX at this point, however:
I believe they are held on with 2 outer bolts, one of which you got out.
But thats not the way to do it, there should be a center bolt that frees the spring to allows to tension on the chain.
Got a manual ?? C'mon, we have free one's here!!
Howdy
05-15-2012, 07:37 PM
Why are you removing it? If your replacing the cam chain, doing a top end, ect you don't have to remove it. You can release the tension on it without removing it.
Howdy
shortline10
05-15-2012, 07:38 PM
Their always very tight !!! Put a little heat on it and it should come loose . The center 6mm bolt just gives you access to the flat head screw that releases the tension to the cam chain .
tri again
05-15-2012, 07:40 PM
I'm lost with the SX at this point, however:
I believe they are held on with 2 outer bolts, one of which you got out.
But thats not the way to do it, there should be a center bolt that frees the spring to allows to tension on the chain.
Got a manual ?? C'mon, we have free one's here!!
Seems like the more I read, the less I know, or I'm a victim of paranoia and tunnel vision,
or both.
Really hate to have a machine down this time of year for a silly mistake.
One mounting bolt popped loose and the other one really feels like it wants to twist off
inside the case.
The center bolt came out ok and I was able to push in through that center hole with a screwdriver and feel the
chain rail flex.
If that mounting bolt twists off, I fear it will be worse to deal with than a broken exhaust stud.
I just like hearing all the worst case scenarios before I start something I can't finish,
or at least have a spare and a backup but promise I'll re read it again.
Dirtcrasher
05-15-2012, 07:47 PM
Like I said, the manual will tell you all.....................
tri again
05-16-2012, 05:21 AM
Just to finish off this thread,
first of all, thanks.
85 and 6 tensioner has about 15 separate parts and it looks like a
coiled spring, maybe 15-20 turns, wants to rotate the adjuster bolt with a certain amount of tension
to load the chain rails.
I thought they might be oil fed or hydraulic or pressurized somehow but that spring screw rotation concept
is fascinating.
Sounds like clockwise rotation with a small screwdriver backs off the tension so it can be reinstalled.
The 87 says to screw in clockwise to unload the tension and
jam it with some 'heard' wire until it gets set back into the engine, lightly mounted,
and then released to do it's job.
Makes me want to get one on the bench to see what really happens..
However complicated they are, apparently they work for years and are almost never an issue unless
physically smashed or needing to be retracted in the event of a new timing chain or guide rails.
Info is kinda splattered between page 69 and 82 with pix on pg 86, btw
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