I spend to much time here....
- Sep 26, 2002
Yes, very good info. I would like to add something. On the drain back holes, as was stated, drill the longer one on pump body in steps (starting with a bit slightly larger than current hole and stepping up until 1/4 as last bit) I have an extended 1/4 bit which makes it somewhat easier. I once drilled with 1/4 (not steeping) and the bit did not stay centered in hole, come through on the outside of body. Also I drill the cover hole to 5/16.
Concerning the number of vanes--I am now a firm believer in nothing but a stock 7 vane GM rotor. I have had 2 10 vane rotors break--destroying both pump halves. This past summer I had 2 friends trans with GM (not aftermarket) rotors in them. Drove me and them crazy. Dave Huseck was kind enough to talk to me many times about my problem of pressure fluctuation. Once I told him I had a 13 vane rotor his exact words were "get rid of the 13 vane and put a stock 7 vane in and all your problems will go away" and they did. Pressure was all over the place-even cooler line pressure would drop from 55 @ min. TV to near 0 @ full TV. Most of the bushings were worn from lack of lube. I did NOTHING but change the rotor. Hope this helps someone. BTW, INDEEDGN what max. line pressure do you LIKE?
Thanks for the insight on the 10 vane Lee! I have a USA replacement 10 vane I was planning to use for a fairly stock overhaul. It looks like I will just use the parts out of it that I can with the 7 vane rotor. Anyone know if I can use the 10 vane slide? (With the 7 vane rotor)