Rocker Shaft Problems???
05-01-2002, 05:04 PM
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Rocker Shaft Problems???
I have an 84 911 Carrera with a 3.2 Liter engine. In the past 6 months, I've had numerous rocker shafts loosen up creating the rocker to make a horrible noise. Does anyone know what the fix is? Is it possible that the shafts got mixed up when the engine was rebuilt 6 months ago creating them to not fit properly in the cam tower? Any help would be greatly appreciated.
Roland
Roland
05-01-2002, 10:49 PM
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You could try RSR rocker shaft seals, it may help. Also, the shafts must be torqued to the proper setting, I think it's 11 lbs, I'll have to check that one.
Last, if the shafts have repeatedly loosened and you continue to run the engine, of course the cam towers may have worn from the movement and you may have an oversize bore condition. You could posibbly need new towers, or it may be possible to hard anodize the bore for a slight buildup on the bore surface which would make the ID smaller. ( but that my be a long shot)
good luck !
Last, if the shafts have repeatedly loosened and you continue to run the engine, of course the cam towers may have worn from the movement and you may have an oversize bore condition. You could posibbly need new towers, or it may be possible to hard anodize the bore for a slight buildup on the bore surface which would make the ID smaller. ( but that my be a long shot)
good luck !
05-01-2002, 10:52 PM
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Forgot the last option ! Measure the shafts, you may have worn shafts requiring replacement, or maybe the shop that did the rebuild used old worn out shafts. (it's a thought )
05-03-2002, 04:06 PM
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When installing rocker arms, as the torque comes up (13.2 lbs), the nut shouldn't have to be held.
If the nut turns (or rather, has to be held) at full torque, either the shaft or the bore is bad.
I had 3 extra new shafts standing standing by when I did my rebuild, and used 2 of them.
There's a little blurb in Andersons book about this, pg 130, upper left. My shafts have stayed put, thanks.
You'll note that the shafts have a 45 deg (or so )chamfer on each end that create an edge that is quite sharp.
As I see it, this area expands (under the proper torque) and this edge "bites" into the bore without permanently denting the bore. Over torquing the bolt is recommended by some.......can't see it, personaly.
I used the RSR seals.....for leak prevention. No leaks either....I have other leaks to make up for them, however
If the nut turns (or rather, has to be held) at full torque, either the shaft or the bore is bad.
I had 3 extra new shafts standing standing by when I did my rebuild, and used 2 of them.
There's a little blurb in Andersons book about this, pg 130, upper left. My shafts have stayed put, thanks.
You'll note that the shafts have a 45 deg (or so )chamfer on each end that create an edge that is quite sharp.
As I see it, this area expands (under the proper torque) and this edge "bites" into the bore without permanently denting the bore. Over torquing the bolt is recommended by some.......can't see it, personaly.
I used the RSR seals.....for leak prevention. No leaks either....I have other leaks to make up for them, however
