Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum - View Single Post - RB20 Crankshaft pulley out of alignment...backing out?

kungfujoe · 01-16-2017, 01:47 PM

Something strange has happened to my RB20DET. It won't keep an alternator/water pump belt because they flip, then break. They are flipping because, while the water pump and alternator are at least visually in line with eachother, my crankshaft pulley seems to be working its way out of the engine. It is visually at least half an inch too far out.

The only thing I've done recently that might have caused this is that I put a big breaker bar on the crankshaft pulley nut in order to brace the engine while I torqued down the flywheel. While we were doing this, the nut broke loose. After we were done with the flywheel, we were sure to torque it down. A couple weeks later, this issue came to a head when I broke a belt. I put a new belt on (which appeared visually to be well out of alignment) and it flipped immediately.

Naturally, knowing nothing else about it, I assumed we had failed to fully secure that nut, so I put a 27 on, and gave it a good hard turn. With the transmission in gear (tried 1st and Reverse) and the handbrake on, I was still able to turn the engine a bit, which I thought was odd (my clutch is nearly brand new. Less than 1000 miles on it, and it's a 6-puck unsprung ACT, so it should be good to go). Basically I was getting stopped by the compression stroke on the engine. Furthermore, I don't feel like that nut went in at all and, despite the compression stroke, I must've been putting at least 100 lbs of torque on it (I think. I'm guessing. I really don't know, but it was a lot).

Anyway, is this the issue? This is so strange that I feel like it could be something else. I can see the rubber bit that I think is supposed to be hidden by the pulley (the harmonic balancer? I'm not 100% sure what it is), and it's almost perfectly aligned with where the belt should go.

Thoughts?

01-16-2017, 01:47 PM	#1
kungfujoe Join Date: Aug 2012 Location: Tacoma, WA Age: 35 Posts: 2 Trader Rating: (0)	RB20 Crankshaft pulley out of alignment...backing out? Something strange has happened to my RB20DET. It won't keep an alternator/water pump belt because they flip, then break. They are flipping because, while the water pump and alternator are at least visually in line with eachother, my crankshaft pulley seems to be working its way out of the engine. It is visually at least half an inch too far out. The only thing I've done recently that might have caused this is that I put a big breaker bar on the crankshaft pulley nut in order to brace the engine while I torqued down the flywheel. While we were doing this, the nut broke loose. After we were done with the flywheel, we were sure to torque it down. A couple weeks later, this issue came to a head when I broke a belt. I put a new belt on (which appeared visually to be well out of alignment) and it flipped immediately. Naturally, knowing nothing else about it, I assumed we had failed to fully secure that nut, so I put a 27 on, and gave it a good hard turn. With the transmission in gear (tried 1st and Reverse) and the handbrake on, I was still able to turn the engine a bit, which I thought was odd (my clutch is nearly brand new. Less than 1000 miles on it, and it's a 6-puck unsprung ACT, so it should be good to go). Basically I was getting stopped by the compression stroke on the engine. Furthermore, I don't feel like that nut went in at all and, despite the compression stroke, I must've been putting at least 100 lbs of torque on it (I think. I'm guessing. I really don't know, but it was a lot). Anyway, is this the issue? This is so strange that I feel like it could be something else. I can see the rubber bit that I think is supposed to be hidden by the pulley (the harmonic balancer? I'm not 100% sure what it is), and it's almost perfectly aligned with where the belt should go. Thoughts?