The crank pulley on our 78 280Z is wobbling. Everything was fine but today when the kid drove it home, it was making a clanging sound. I was able to see why very quickly. The front pulley is good but the rear that is closest to the block is the one that is wobbling. Ideas and fixes?

You need a new one. The rear one is usually part of the vibration damper which is held in place by a rubber interface. If the rubber fails you need to replace the damper. MSA sells a new performance damper that is a good deal.

You need a new one. The rear one is usually part of the vibration damper which is held in place by a rubber interface. If the rubber fails you need to replace the damper. MSA sells a new performance damper that is a good deal.

Aloha,

That's what I thought. I have euro damper in the box in the garage but it will do me no good because the car has A/C. Thanks for confirming my initial thought. Mahalo

David, I have no personal experience with this shop, but he rebuilds harmonic balancers for Zs and Corvairs. www.dalemfg.com/daley_001.htm

He was talked about on another site and they all had good things to say about him. Much cheaper than a new one from MSA. Just my 2cents.

Cheers, Mike

Does anyone know what the bolt size on the front of the pulley is?

If the 78 is the same as my 73, it is 27mm or 1 1/16 inch.

Bonzi Lon

I bought one from Nissan about 8 months ago so as far as I know they're still available. Same bolt for all except the earliest L24. 12309-21000 is the bolt and 12308-65000 is the washer. Total was about $9 IIRC.

Thank you Bonzi and Steve, I have 27mm spocket in the garage so I am GTG. We plan to reuse the bolt but if it is also defective as was the pulley we will get one from Nissan using the part number listed. I hope this replacement goes well. We got a new factory pulley from MSA, got it for a good price.

Any last minute advice before we tackle the project?

Pretty straightforward from there, just don't get the 'while I'm at its' like I did. I set out to replace the pulley and then I decided to do the front cover seal and the timing chain tensioner. By the time I was done, I ended up doing a valve job as well since I had ruined the head gasket taking off the front cover.

Thanks Steve....everything is off except the pulley itself. I thought I had a good puller...but no, the bolt is too long and don't want to remove the radiator to use it. I am off to find one...Napa...Sears...here I come.