Several months ago I bought an aftermarket optispark (vented) distributor and disassembled the necessary parts on my 94 Z28 engine to install it (radiator, water pump, balancer, smog pump, etc.). Just yesterday I decided to finish the job. I managed to install the distributor seal quite easily but it took 3 tries with the water pump shaft seal. I ended up making a special installation tool from the old w/pump coupler (GM 10128334). I simply ground off the "grooved" end at an angle to make it a tapered end, sanded it, and then buffed it on my wire wheel to make it as smooth as possible. It worked great using oil, a 24mm long socket, and being very careful. I can provided a picture of this special tool if anyone is interested.

My question is does it make any difference which end of the new GM coupling (GM 10128334) goes toward the block? One end of the coupling has a groove about 1/8" or so from the end. I see no purpose for this groove. I can not remember how I took it apart.

Dave

 

For the o-ring, all you needed was a sharpie pen cap.

I don't think the orientation of the water pump coupler matters. I upgraded to an electric pump ages ago.

 

the groove goes towards the block per manual; not sure why (or that it really matters). I have the official GM specialty tool (looks like a pen cap) and the only way I can ever get the seal on is to install the seal after I put the cover back on.

 

Thanks, I thought the grooved end went towards the block but I just wanted to make sure although I see no purpose for the groove.