Lining up BB oil pump gears
Thread Starter
Instructor
Joined: Jul 2016
Posts: 195
Likes: 37
From: Poway CA
Lining up BB oil pump gears
As I am putting my L-36 back together, I cleaned out the stock oil pump which has an acceptable clearance and appears brand new. After cleaning it out and putting the gears back in, I see that the two dots don't line up because they are both at the top of the teeth- one is not in a corresponding trough. Because of this, the dots can only be close, one dot ahead or behind the other, depending on how I place the last gear into the body. I would guess they should go back in their original position because of a wear pattern established but is this critical? I rebuilt the motor years ago and don't remember coming across this issue.
I tried looking in the overhaul manual, online, and other books I have but could not find anything.
I know I can always get good input here. Thanks for any thoughts!
I tried looking in the overhaul manual, online, and other books I have but could not find anything.
I know I can always get good input here. Thanks for any thoughts!
Race Director
Joined: Nov 2006
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From: Sunshine Coast, Queensland, Australia
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I'm thinking your over thinking it. I also find it odd that the dots don't line up. None the less, these things are machined to very precise tolerances. they run in oil 100 percent of the time. I have rebuilt that many oil pumps on antique Harley's which did not have dots on the gears. no long term issues.
Le Mans Master
Joined: Mar 2004
Posts: 7,493
Likes: 1,501
From: Little Rock AR
You could replace just the gears. Melling sells an oil pump rebuild kit. Includes gears, coupling, pressure regulating valve, spring(s). Reuse the good heavy GM casting and keep the existing pickup that is probably welded to the casting. Just an option.
Thread Starter
Instructor
Joined: Jul 2016
Posts: 195
Likes: 37
From: Poway CA
Thanks for all the input- I had read I needed to mark the relative positions of the teeth in a big block rebuild book and was a bit concerned- I found that Melling pump dots seem to be the same way-just a way to know which end goes up. It makes sense since there is no possible way to line up the dots, but I was concerned about a possible wear pattern like cam lobes and lifters.
l do appreciate the help to all those who contributed.
l do appreciate the help to all those who contributed.
