I'm replacing the Opti unit on my 1996 Z28. I have the 3 bolts out that hold the lower pulley to the crank hub, but the pulley won't budge. I've soaked the assembly with penetrating oil and tried to get it to spin, but to no avail.
It appears as if I can use a 3-point puller to remove the ring. Can anyone here please confirm the thread size in the holes on the pulley? It looks like 5/16", but the holes are a bit rusty and I'd expect the thread to be metric.

Thanks for any help,
Rick

 

Here's how you do it.

http://shbox.com/1/pull_pulley.jpg

Leave the crank hub bolt in.

 

Spray some PB Blaster on the front seam and on the back side of the pulley

 

I'm pretty sure that the holes in the harmonic balancer aren't threaded. If you're talking about the hub it's mounted to, I don't know the answer. If you need to get the balancer off, a small three point puller will work. Mine came off rather easily, but I didn't try pulling it off by hand.

 

The crank pulley on my '96 looks different than the one in Shoebox's picture. My pulley has small tabs between the three bolts that hold the pulley to the hub, and the tabs are threaded. These tabs with the threaded holes are located exactly where the jaws grab the pulley in Shoebox's picture. In my case, it seems a three-point puller with bolts (instead of claws as shown) would be easiest.

My crank pulley is original, so I guess the '96 is a bit different than the model Shoebox is working on.
I'd like to confirm the thread size in those tabs on the pulley.

Thanks again,
Rick

 

Wierd, but cool! I have a 96 and the balancer is like the one on Shoe's site. Pulled it the same way too! I guess you probably can use a 3pt puller, which makes things easier. You could go to the hardware store and buy some different thread pitch 5/16 bolts and try to thread them in. Also, if they are metric, keep in mind that 8mm is real close to 5/16.

 

The good news is, once you get the damper off this time it won't be that difficult next time. Once it is off, use some emery cloth to clean-up the OD on the hub (remove rust) and ID on the damper. Then put some grease on the hub before you reinstall the damper to prevent future rust.

I have an aftermarket SFI damper which I take off often and I don’t have to use a puller. I just slip it off with my hands.

Also, on your new GM Opti. I had the rotors screws get loose on a GM unit a while back. So you may want to remove the Opti cap, remove the rotor screws add some thread-locker then reinstall the screws ensuring they are tight.

WD

 

I got the crank pulley off using a 3-point puller and 3" x 5/16" bolts. Worked like a charm...
I'm sending the Accel Opti back to Summit in exchange for a GM unit. I suppose while I'm doing this job I will replace the water pump.
What is the best source for a water pump, water pump gaskets, and a new Opti seal?
I'm replacing the wires while I have everything apart, and I suppose I'll swap the plugs, too. What plugs do you guys recommend for a driver-type car?
Is there anything else I need?

Thanks very much for the help,
Rick

 

I have an aftermarket SFI damper also and need to remove it to replace opti seals. I have tried Blaster and still no luck. Which puller do I need to remove this unit the first time? The only holes in this unit are for the bolts the secue it to the hub. I also plan to check the rotor screws as you suggested.

Thanks!
Mike

 

I use a small rubber mallet and tap on oppsing sides and the damper falls right off the hub. Once its off I then do as described above by cleaning it up and greasing it so the next time it won't be such a pain.

 

Pulley differences are noted here: http://shbox.com/1/engine_front_diagram.jpg