View Full Version : DIY: Putting a1 shafts into z3 pump

04-21-2008, 07:08 AM
Well if you are running the z3 pump in a K24 or any motor for that matter you need to swap the balance shafts over from the oil pump that came on that block to the z3 pump housing. Ok first start off by removing the bolts you see here. There are 3 on the right side that I believe to be 12mm and 5 more 10m bolts on the left side of the cover. The 3 12mm bolts get tq'ed to 20 ftlbs on when putting them back in at the end of the thread.
With the cover off this is what we are going to be looking at. If you rotate the shafts up like in the picture then you can slide the lower one out first.
You then need to remove this 14mm bolt from the other balance shaft. Hit this puppy with a good impact wrench and it will come right off. If you don't have one then you could also use a pipe wrench on the shaft to hold it while using a normal ratchet(not reccomended). If you do go this route then be carefull where on the shaft you put the pipe wrench as to not mess up the weights.
I have now removed the shafts from both pumps and you can see the difference here in this picture. The k24a1 shaft is on the left and the z3 is on the right.
You can see here where the k24a1 pump cover has holes in it so the shafts don't make contact with the cover. It is not a good idea to use the k24 cover on the z3 pump since all the bolt holes don't line up and Doug made a good point about the oil getting whipped up by the shafts.
I started out grinding it with this really crappy dremel bit and it took forever. This is where we are going to be grinding though.
Doug showed me the light with this super sweet flap wheel:mcool: You are going to grind a few mm off of the cover and we will check the clearance once we get the shafts installed. Clean up that surface REALLY good since we dont' want any aluminum debree getting in the oil or the engine. Good soap and water on that puppy is a must and then give it a light coat of oil again:mwink:
Ok reinstall the shafts in the same order they were removed and make sure to line up the timing marks on the gears. The gear with one dot will slide in between the two dots on the other gear. Don't reinstall the 14mm bolt and gear on the balance shaft yet since we still need to check the clearance of the shafts.
Bolt down the cover and spin the shaft with your hand. If it is not touching anything and spins freely then you can pull the cover off back off. Grab a hold of that shaft again and reinstall the 14mm gear and bolt that the oil chain is going to connect to. Rebolt down the cover and enjoy your new oil pump.

04-21-2008, 08:13 AM
Great writeup!

Make sure to properly torque the three larger bolts, as they retain the balance shaft bearing shells just like the girdle retains the main crank bearings.

04-21-2008, 08:15 AM
Great writeup!

Make sure to properly torque the three larger bolts, as they retain the balance shaft bearing shells just like the girdle retains the main crank bearings.

Good point Doug. 20 ft lbs!