Allan-Herbie Report post Posted April 12, 2018 Had my car for 3 years with no issues. Then all of sudden the pully loosened and threw a belt. Since then we have replaced 2 additional belts as the pulley continues to loosen quickly and it blows the belt off. Any ideas? We torque it to factory spec, and it continues. Quote Share this post Link to post Share on other sites More sharing options...
Destructo Report post Posted April 12, 2018 Stupid question, but are you using OEM belts or aftermarket? Also, have you considered replacing the pulley and hardware? Quote Share this post Link to post Share on other sites More sharing options...
Stimpy Report post Posted April 12, 2018 Loctite? Quote Share this post Link to post Share on other sites More sharing options...
Murcie612 Report post Posted April 12, 2018 Make sure the belt alignment especially on the ac compressor pulley is correct. Also make sure all the accessory pulleys are in good shape, check all pulleys while the belt is off. Quote Share this post Link to post Share on other sites More sharing options...
emanon Report post Posted April 12, 2018 Check the bearings on the pulley, it should spin freely enough you dont need an overly tight bolt. Something is binding inside the bearing, spinning the inner race and causing the bolt to loosen. Red loctite may help prolong the problem, but i suspect the next time it throws a belt the pulley will be seized completely. Im a little surprised it spins in the direction to loosen the bolt. Typical practice with anything spinning is normal operation would tighten the bolt, even if it meant using a left hand thread. Quote Share this post Link to post Share on other sites More sharing options...
deekss Report post Posted April 12, 2018 I had this, and so did Simon George with the high miler from Evo. The taper was worn inside the bottom pulley. A new pulley fixed the issue. There is no keyway or other mechanism to secure the pulley other than the bolt. The pulley is held tight on the taper alone by the bolt. If it's not the pulley that's worn, it will be the crank !! I understand however that this is rare, as the pulley is softer than the crank. Also on mine, as I'd been through a couple of belts, the spacer with the long bolt that you have to remove to change a belt, on the power steering pump bracket frame, had become squashed. This meant that the idler pulley on the frame was out of line, and causing the belt to run out of true. I shimmed up the spacer to get everything back in line, and had another one turned at a later date. Those are your problems ! Quote Share this post Link to post Share on other sites More sharing options...
emanon Report post Posted April 12, 2018 To clarify, I was talking about an idler pulley. Is it an idler or a fixed pulley (crank, etc)? Quote Share this post Link to post Share on other sites More sharing options...
deekss Report post Posted April 13, 2018 To clarify, I was talking about an idler pulley. Is it an idler or a fixed pulley (crank, etc)? I knew what you meant Allan. I hope you didn't impulsively get jiggy with the Loctite.... Quote Share this post Link to post Share on other sites More sharing options...
Allan-Herbie Report post Posted April 17, 2018 Anyone know what the torque spec is on the pulley? Quote Share this post Link to post Share on other sites More sharing options...
Allan-Herbie Report post Posted April 21, 2018 Anyone? Quote Share this post Link to post Share on other sites More sharing options...
AMHParts Report post Posted April 21, 2018 I think I have them Allan, I 'll email them over Quote Share this post Link to post Share on other sites More sharing options...
Allan-Herbie Report post Posted April 21, 2018 I think I have them Allan, I 'll email them over Thank you! Quote Share this post Link to post Share on other sites More sharing options...
Digibeam Report post Posted April 22, 2018 Power steering pump support frame,AC compressor,alternator 45 +/- 5 Nm Guide pulley screw 49 +/- 5 Nm Automatic tightener pulley screw 45 +/- 5 Nm Sorry for the late reply, hope this helps Also, for clarification, this is for Murcielago, if you need for Diablo let me know Quote Share this post Link to post Share on other sites More sharing options...
FrankD Report post Posted April 23, 2018 Do you have the torque specs for lugs on a 1998 Diablo ? thanks Quote Share this post Link to post Share on other sites More sharing options...
Digibeam Report post Posted April 24, 2018 Seems to be 98Nm for the wheel lugs, which is what I am assuming you are referring to. Quote Share this post Link to post Share on other sites More sharing options...
whiteout Report post Posted June 1, 2018 PM Gonzo. The belt cannot be centered on the pulley, it has to be on one side otherwise it will get thrown. Quote Share this post Link to post Share on other sites More sharing options...
THIRDGEN Report post Posted July 6, 2018 Check the bearings on the pulley, it should spin freely enough you dont need an overly tight bolt. Something is binding inside the bearing, spinning the inner race and causing the bolt to loosen. Red loctite may help prolong the problem, but i suspect the next time it throws a belt the pulley will be seized completely. Im a little surprised it spins in the direction to loosen the bolt. Typical practice with anything spinning is normal operation would tighten the bolt, even if it meant using a left hand thread. Just FYI, use blue loctite only and green if its a fine thread. If you use red, it will take a torch to get it off. Matter of fact I think it even says so on the tube. Quote Share this post Link to post Share on other sites More sharing options...
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