How to re-assemble oil pump?

[belling]

I took apart my oil pump (1970), and now when I tighten the nuts it seems to bind. I've heard of other people having this problem, is there some magic to getting it to spin freely?

[Tim Walsh]

I belive the experts say don't disassemble it and if you do, mark the orientation of the gears so that it can be put back together exactly right.

My sugestion is to just pick up a later oil pump (76?-89) since I'm assuming you're doing the oil bypass mod and the later pump has a larger pressure side.

[belling]

I wasn't planning on doing the bypass upgrade, so I guess I'll have to find an old oil pump.

As soon as I pulled it open I knew I shouldn't have done it. :P Curiosity killed the cat and all.

[ChrisBennet]

C'mon there's something like 4 parts isn't there? I'd try the 16 combinations before I gave up...
-Chris

[belling]

I've got the parts right. With it all closed up and the nuts finger tight, it spins fine. Tightening down the nuts and it gets hard to turn. I'll keep playing with it...

[NevenM]

There is generally no problem with disassembling and recon oil pumps. You can reset the end clearance by 'glass plating' the housing. I'd firstly try and determine what is binding, ie are both sets of gears tight, Try assembling it with the top and then the bottom set of gears, if they spin freely then the end play is ok, it is the engagement of gears. Then 'incrementally' assemble the pump, do the pressure one first and then the scavange one (which has 2 gears IIRC). It is also possible to assemble the pump incorrectly (which my engine builder did!) with the shafts transposed (I noticed this as I fitted it to the crankcase)

HTH

Neven

[Jim Richards]

it'll turn better with some oil, even using WD40

[snowman]

I have dissassembled an early oil pump, put it back togather several differen't ways, including the exact way it was taken apart and found NO difference. Anyone else found the same?

[belling]

I got it back together fine. There was some grit in the holes the little fitting posts push into, and it seems like they were deforming the case a bit. I cleaned everything up really well, oiled it up, and it turns fine. I diddn't change which gear goes where, or which way the gears go on the shaft, but I have no idea exactly how the gears were meshed. It doesn't seem to matter.

Thanks for the help!

[snowman]

ITs supposed to make some kind of difference, but in the case of an oil pump does it really? Anyone with some kind of long term experience on this subject?

[126coupe]

$175.00 came from one of my race engines works great