Tensioner Roller Failure '88-S4
#16
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Join Date: Feb 2010
Location: Cobourg, Ontario
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Thanks Malcolm, Roger did mention the lower idler wasn't needed also. My concern with that is, there is now an exposed area of the timing belt at the bottom of the engine below the crank pulley. A problem for dirt/grime to get in? I realise the balancer is there to provide some distance, but is there a plastic cover or something out there that could cover up the gap? Or do I perhaps, pull the bearings off the idler & just put the bracket back on the guide pins?
#17
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The centre plastic cover and harmonic balancer should prevent any debris from entering.
I've had the lower idler assembly off of my my car for years now, I have one of the first batch of porkensioners............no concerns at all.
I've had the lower idler assembly off of my my car for years now, I have one of the first batch of porkensioners............no concerns at all.
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Just to add a note about the OEM roller you originally purchased and subsequently failed.
It was most likely an INA bearing and I feel just bad luck that it failed.
Most of the parts suppliers buy from the same sources and more than likely sell the same parts in this situation.
Great looking car!!!
It was most likely an INA bearing and I feel just bad luck that it failed.
Most of the parts suppliers buy from the same sources and more than likely sell the same parts in this situation.
Great looking car!!!
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Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."![thumbsup](https://rennlist.com/forums/graemlins/bigok.gif)
![](https://cdn.shopify.com/s/files/1/1694/8685/files/928sRus_rennlist.png?v=1621798567)
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
![thumbsup](https://rennlist.com/forums/graemlins/bigok.gif)
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
![thumbsup](https://rennlist.com/forums/graemlins/bigok.gif)
#20
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With reference to Mrmerlin's post #2 regarding "the slight wiggle" to the tensioner roller bearing.
I recently completed a TB replacement and noted this and I checked it against the previously changed roller and noted the same "wiggle". My evaluation was that this "wiggle" allows the roller to set itself up into the same plane as the belt thereby insuring that the TB does not get any imparted twist into the belt due to any small axial out-of-alignment from the tensioner roller assembly.
Tails 1990 928 S4 Auto
I recently completed a TB replacement and noted this and I checked it against the previously changed roller and noted the same "wiggle". My evaluation was that this "wiggle" allows the roller to set itself up into the same plane as the belt thereby insuring that the TB does not get any imparted twist into the belt due to any small axial out-of-alignment from the tensioner roller assembly.
Tails 1990 928 S4 Auto