Snapped the idler pulley clean off.....

DrumrBoy

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Sorry to not include pictures but it happened on track and the pieces are littered around....several folks did find pieces (in their headlight in one case!).

Has anyone ever had the bolt holding the spring-tensioner pulley snap off? If it were any other shaft I would think maybe the belt was too tight, but this was the idler....by definition it should provide enough slack to not break itself right?

Maybe just a fluke, but wondering if its happened to anyone else.....
 

Richard Koch

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I had that happen one time on my 1999 RT-10. It appeared like the metal crystallized and the stud snapped off. Unfortunately I was up at Johnstone Ridge on Mt. St. Helens on a Sunday afternoon. I was lucky enough to be able to ge a part from Larry's Viper Parts and we were able to repair it theree. Mine broke just as I drove into the parking lot, so no major damage occurred. It was a bit of a pain replacing it and we needed a metric box ratchet to get the nut tght. We put it back, replaced the serpentine belt, and topped off the coolant. I have always wondered whether someone had over tightened in the past. I made sure I didn't tighten it too much so it wouldn't happen again.
 

Fatboy 18

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I did it after replacing the pulley with a Billet aluminum one, the OEM bolt could be a little longer ;) I think I over tightened it and broke the casting

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You can see by the amount that broke off that the pulley was being held by only that much bolt thread!
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So I carefully cut the casting and filed the face flat, then got a spacer machined up and ran a tap down the hole to increase the thread.
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Then purchased a longer bolt to hold the pulley :)
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Job Done, without having to replace the timing cover :)
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DrumrBoy

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Good thought on the longer bolt and deeper threads. Mine appeared to snap forward of the spring assembly, bolt just sheared 90 degrees.....but I will check thread depth. Thanks guys.
 

Roysviper

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Sorry to not include pictures but it happened on track and the pieces are littered around....several folks did find pieces (in their headlight in one case!).

Has anyone ever had the bolt holding the spring-tensioner pulley snap off? If it were any other shaft I would think maybe the belt was too tight, but this was the idler....by definition it should provide enough slack to not break itself right?

Maybe just a fluke, but wondering if its happened to anyone else.....


YES....I was driving a Roe Supercharged 96 GTS that I use to have and it did the same thing.......I went to the nearest shop....Auto Zone I believe, and for just a few dollars they had the EXACT replacement pully for it and said it is a universal pully that is used on many different type of cars.....boy was I lucky....put it on right there on the side of the road and drove on with no further problems at all........easy, quick fix......:headbang:
 

JoelW

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Sorry to not include pictures but it happened on track and the pieces are littered around....several folks did find pieces (in their headlight in one case!).

Has anyone ever had the bolt holding the spring-tensioner pulley snap off? If it were any other shaft I would think maybe the belt was too tight, but this was the idler....by definition it should provide enough slack to not break itself right?

Maybe just a fluke, but wondering if its happened to anyone else.....

Of course you'll think this is crazy but it happens on Dodge Grand Caravans pretty regularly if the tensioner is not replaced. The tensioner freezes and then breaks the bolt off or spits the belt off the pulley. I used to replace the tensioner as a matter of course when I serviced Caravans. Same one bolt design. Same thing may have happened to you - could even be the same tensioner or a very similar design. Check the tensioner bearing or spring for a reluctance to release. Part is cheap and walking down the road talking to yourself not so much fun.
 
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DrumrBoy

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The tensioner freezes and then breaks the bolt off or spits the belt off the pulley.

That makes sense; I still have the spring tensioner piece and can check it for seize. Thanks all for the input; I'll replace the whole assembly (tensioner spring shaft and pulley....to be sure!
 

Fatboy 18

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I think Jance GTS, is referring to the Under Drive pulley, The pulley is smaller than stock. No one tells you this when you swap them all over ;) So I ended up having to purchase a new (different length) belt. Not sure on the standard belt length, but my new 7 rib belt measures 1980mm Ive not noticed any diffrence in engine or cooling performance and to be honest some of the Billet pulleys are heavier than the OEM steel pulleys........But it looks good :D

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