Alejandro Guerrero

Hello, I am trying to install my crank hub and came to a couple of speed bumps.
1. What is this round thing? I can't find a mention of it in my FSM but it exists and it was on my shelf next to my crank hub. Should have paid attention while taking stuff off but here we are. Also, Do I need to remove the key that the crank gear is on before installing the hub? The hub doesn't have a key slot in it so I know I need to take the first one off, but it is hard to see if the second one will get in the way.

Thanks

Nomake Wan

Do you have a '96? If so, that's the Crank Position Sensor tone ring. It goes on first, and is keyed. The hub is designed to but up against it when installed (and is why the '96 hub is 0.100" shorter than the 92-95).

Alejandro Guerrero

That explains it. I have a 94, but am running a 96 timing cover, gen 2 opti, elecatric water pump and a normal timing chain so that circle thing came with my 96 timing cover. Appreciate the help. So that means I don't remove that first key then, only the second.

mtwoolford

If you want to retain the crank postioner ring, and the stock (unkeyed) crank hub, you need a key specific for a 96 LT engine, and the one you have is not it. The 96 key will be ground down so that it has a shoulder (normal key height) which engages not only the lower timing chain sprocket, but also the slot in the ring youre holding; the thicker part of the key goes in towards the engine, and the thinner part is level with the crank outer diameter, allowing the crank hub to slide onto the crank snout and butt up against the crank positioner ring (make sure the slot in the ring is actually engaged with the shoulder of the key) , thereby holding the ring in place. Ignore the second slot in tne crank hub (furthest from the engine) unless you're running an aftermarket crank hub with a keyway machined into it.

Nomake Wan

To add to the above, here's a photo I stole from an eBay ad that illustrates the differences pretty well:

Alejandro Guerrero

Thanks for the help guys! I don't really want to take the timing set apart so I may just look into getting a letter hub. Since my car is still running obd1 do I need to do the crank sensor? I just have the 96 cover to account for my gen 2 optispark.

Nomake Wan

You don't need it, but if you don't install it you'll need to put a bolt or something in there so that you don't spew oil everywhere obviously. If you want to use an OBD1 hub, just leave the CKP toothed ring out and use the OBD1 crank key.