Ok I am doing a CSI install right now...I went to pull my hub off and I noticed that the hub itself is not keyed at all...however the part of the crank, aka the part that remains inside of the timing cover IS indeed keyed. (my friend called it a woodruff key? spelling?)

anyway, point is, is that I have been fighting a small oil leak for quite some time now, and I am wondering that the hub may be wrong. I had the hub replaced last year thinking that the rear of the hub may have been scored or warped (especially from a bbk underdrive pulley install) prematurely causing the seals to fail. Well sure enough it did not totally fix the leak!!

The replacement hub part # that was used is 12553250

When I look this up on GM parts direct it does not list specific years that this part is to be used on. I am wondering if this is the wrong one!! I want to nip this leak in the butt for the last time. I am doing the work now, and I wondering if either I got something that is GM being dumb, or a mechanic who did the previous "fix" installing the wrong part.

HELPPP please...other than this the CSI install is going fine, I just wish the rest of this was as simple...

 

The crank hub that you purchased is the correct one. 1996+ hubs are slightly shorter to make room for the crankshaft reluctor ring for the CPS. Stock crank hubs are NOT keyed or indexed to the crankshaft, and rely on a press-fit onto the crankshaft snout. This is absolutely normal. The hubs do not go bad as to induce leaks, but the front seal on the timing cover does. Have you replaced the front main seal on the cover yet?

 

I'd suggest you put dye in you oil and use a black light to determine where your oil leak is coming from. There are two seals above the crank seal (opti and water pump) that be the source of your leak as well as the timing chain cover seal and oil pan gasket.

 

thanks guys, yeah i have the entire rebuild kit from thunderracing..i am going to swap all fresh seals in there....i doubt the original work done by the mechanic included rebuilding the timing cover...

anyway the install is going smoothly...about to rip the guts out of the stock housing!

 

Well its Sunday morning, and I think I hit a wall!

I am trying to get the hub back on (the csi and opti installed very easily) and this damn hub will NOT get threaded.

I have no markings as to where it would need to line up with or anything because I rotated the crank manually anyway when doing the timing chain swap.

Earlier, RamAirTA said that the snout and the hub ARE NOT keyed to each other. Does this mean that the hub can go on any way?? I do however have markings on the balancer relative to the crank pulley, and I have noted that they only fit on 1 way to the hub.

So question is - whats the best way to get the hub not only ON the snout, but ALSO orientated to the crank snout (if any is needed for that matter)...

THANKS guys, I want to fire this thing up sooooonnnnn

 

There are several ways to do it, but may be just as easy to look for the shadow of the keyway inside the hub and line that up with the keyway on the crank.