Underdrive pulley snapped off?????
well, last friday i was driving normal down the road and all the sudden i lost power steering, temp gauge started to rise, etc. shut the car off and looked under the hood and noticed the belt came off the pulley. towed it back to the house, looked underneath and the underdrive pulley was hanging there, all four bolts were snapped off! have no idea how it happened other than from the vibration from the billet lower engine mount slowly rattling them lose or something. i'll post pics soon...........
the underdrive pulley that runs the alternator, ac, etc. there is another cam gear lookin thing that drives the timing belt that the underdrive pulley attaches to. that is where the bolts are broken off and are stuck in. it sucks and i wonder how much the parts are goin to cost.
the underdrive pulley that runs the alternator, ac, etc. there is another cam gear lookin thing that drives the timing belt that the underdrive pulley attaches to. that is where the bolts are broken off and are stuck in. it sucks and i wonder how much the parts are goin to cost.
no. when the bolts were coming lose they widened the holes on the pulley, then broke off. so, i need a new pulley, bolts and its looking like i'll need the timing belt gear that is on the crank. doesn't look pretty..........
Ok that is the harmonic balancer That you replaced. What happpened is the After market underdrive pulley has holes that allow a slight amount of play around the bolts, or the bolts weren't tightened correctly. The peice you destroyed is called the Crankshaft timing gear, which need to be replaced. I would just put the Stock harmonic balancer back. You will get more out of a lightweight flywheel than the underdrive pulley anyway.
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From: Spec-Ops Motorsports, Fayetteville, NC
i dont believe the part was aftermarket or replaced, it was stock.
Matt, start looking for someone parting out a wrecked one and see if you can get those parts from them. You could also maybe get in touch with that place brad had his car at and see if they have a car up there.
Matt, start looking for someone parting out a wrecked one and see if you can get those parts from them. You could also maybe get in touch with that place brad had his car at and see if they have a car up there.
Did your serpintene belt come off the "track" in the pulleys? Does your AC work? VIbrations at about 3-4K RPM, whereas you can feel the vibrations in your seat? If so, I know what your problem is.........
Ok that is the harmonic balancer That you replaced. What happpened is the After market underdrive pulley has holes that allow a slight amount of play around the bolts, or the bolts weren't tightened correctly. The peice you destroyed is called the Crankshaft timing gear, which need to be replaced. I would just put the Stock harmonic balancer back. You will get more out of a lightweight flywheel than the underdrive pulley anyway.
The crank pulley has two functions. First is to run the serpentine belt and second is to dampen tortional vibrations. A one piece crank pulley will not dampen those tortional vibrations. This will end up vibrating the bolts loose. On MKIV Supras, I have seen them contribute to clutch / flywheel / TC / flexplate bolts all loosening also.
I highly suggest staying away from any pulley that eliminates dampening. The HP gained from turning the accessories slower is not worth the risk of damage and down time due to bolts coming loose.
I highly suggest staying away from any pulley that eliminates dampening. The HP gained from turning the accessories slower is not worth the risk of damage and down time due to bolts coming loose.


