A couple of years ago, I installed an ATI balancer on my car, as preventive maintenance. I noticed a couple of months ago, when changing the oil prior to winter storage, oil all over the oil pan. Therefore, it appears I have a leak somewhere, which I'll fully investigate in the spring, as it's too cold in the garage now.

When I originally worked on the car, I took the opportunity to install an LS2 timing chain, as it's supposed to be an upgrade. Naturally, I had to remove the oil pump to do this. I read in one of the "aftermarket" reference books that when installing the pump, you should remove the front cover of the oil pump, loosely bolt the pump to the engine, then fiddle with the pump body's location, while placing 0.002" shims somewhere around one of the pump's rotors. I assume that this is supposed to center the pump on the front of the engine.

This brings up a question, since I might have to go back in there, if the front cover is the source of my oil leak. Since the reference book wasn't too clear about the method with these shims, I referred to the factory shop manual. The FSM didn't seem to mention anything beyond "carefully bolting the oil pump in place". So that's all I did.

Secondly, 0.002" is PRETTY DAMNED THIN!! I didn't realize that shim stock that thin is available. How would you ever be able to place something that thin in place, let alone be able to accurately use it as a measuring tool?

Therefore, is this really necessary? By not using this method, did I mess up my oil pump? Is this step really necessary?

 

I used three sets of feeler gauges to shim the pump. I believe some will say it is not necessary.

 

Check out youtube. Tons of videos about shimming and porting ls oil pumps. VERY easy mod.
So easy I can't believe company's charge big bucks for a ported oil pump.

 

Personally, I think this is something started on the internet. I have done many, shimmed none. No problems anywhere. As you stated, if it were that critical, the service manual would include it. How many gerotor pumps have you shimmed in other applications.

Doesn't the book you are referring to also show the damper installation with a longer bolt? I think I have the same book and if it is the one I am thinking of, nice pictures but I wouldn't exactly follow it in deference to the GM Service Manual.

 

I appreciate the input. But while doing some research on the internet, yesterday, A) I saw a couple of vendors that sell the proper shim stock, but don't show a CLEAR picture of how to use it; B) and a couple of other "home mechanics", who like me, looked at the factory shop manual, which doesn't mention any special procedure in installing the pump.....

 

The book I was referring to is entitled 'How To Build High Performance Chevy LS1/LS6 V-8s', written by Will Handzel.

 

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Sorry I was taking about sing the feeler gauges to center the pump on the crank. I placed my 3 in a triangle pattern. I think I used 0.003? There are plenty of pics online.

 

This is how I did it the first time I installed my oil pump...(copied pic from internet)

Used the method cause a ton of guys on the other LS forum recommended doing it this way.

2nd time I had my pump out for a cam swap I just threw it back in without using the feeler gauge method. I couldn't get the pump cover off (used locktite and started stripping the torq screws).....

If I ever have my pump out again I'll let you know if there is any difference in wear, but I'd bet it would be minimal if any.

 

Excellent picture!

I can see the usage of the shim stock, but I didn't have any in the tool box, and wanted to get the car buttoned back up. So, when I re-installed my pump, I loosely installed it, moved it to whatever "center" I could feel by rocking the pump on what little movement there was in the bolt holes, and tightened it down.

 

Didn't shim mine. No problems that I can tell.

 

Didn't shim mine.

 

I'm going with this, I have a Mastiff too and I know that no one with a Mastiff would ever be wrong

Attachment 48345013

 

Hum, wonder if he's going to get the message. 5 years old. Thread

 

Interesting to see this discussion float to the top, and I was the author!!

So far, after about 6-7000 miles of driving, I've experienced no issues with the engine. And with respect to the oil leak that I originally mentioned, I checked the torque on the lower oil pan retaining bolts, and found that they all were a little loose. I forget what the exact torque value for them is, but it's pretty low, something like 90-100 INCH pounds of torque, and even at that low a number, all of mine were somewhat loose. I snugged them up, and it's been OK ever since (about 3 years, now).

 

thanks for piping back in, this is Corvette Forum, no one ever leaves - and thanking someone for advice they put years ago is my style .... my thread - and for those who are concerned I'm posting a C3 in a C5 page, the front suspension is C5
https://www.corvetteforum.com/forums...ic-tew-25.html