3.4 oil pump shaft install

[jetta90]

Good day to all.................just doing the very common intake gasket repalcement on my 2002 Impala with the 3.4 engine.
I've reached the point of having everything pulled off including the leaking lower intake gasket. I'm going to replace the o-ring on the oil pump drive shaft while I have all the components off for easy access.
I've pulled the oil pump shaft out of the block and I wonder if there is anything to watch out for when instailling it back in the block.
Is there something that needs to be aligned?? When looking inside the block through the hole the oil pump shaft fits into, all I see inside is an hexagon(?) shaft sticking up vertically that fits into the bottom side of the oil pump shaft once i slip it back in the block. Where does the other end of this hexagon shaft go to.................to oil pump itself I guess? Does it fit into the pump in a certain way? It looks very loose just sitting there without the shaft in place. Almost looks like it could fall over in the motor right now.
Any thoughts or "heads up" on this would be greatly appreciated.
Thank you.

[maxwedge]

Yes you need to line up the pump drive and catch the cam gear at the same time, the teeth are helical and the drive will turn as it goes in so the initial alignment is tricky, if you had marked everything on disassembly coming out and did not turn the engine over, it is just like a dist. install that has the oil pump drive on it.

[The_Mechanic_33]

Oil Pump Drive Replacement

Removal Procedure

1. Remove the upper intake manifold.
2. Remove the fuel feed and the return pipe from the fuel injector rail.

1. Remove the oil pump drive bolt.
2. Remove the oil pump drive clamp.
3. Remove the oil pump drive.
4. Remove the oil pump drive seal.

Installation Procedure

1. Install the oil pump drive seal. Coat the seal with rtv.
2. Install the oil pump drive. Notice: Refer to Fastener Notice in Service Precautions.

1. Install the oil pump drive clamp bolt. Tighten the bolt to 36 Nm (27 ft. lbs.).
2. Install the fuel feed and the return pipe to the fuel injector rail.
3. Install the upper intake manifold.

[The_Mechanic_33]

This bulletin is being issued to revise Steps 1 and 2 of the Lower Intake Manifold Installation procedure in the Engine Mechanical sub-section of the Service Manual. Please replace the current information in the Service Manual with the following information.
The following information has been updated within SI2000. If you are using a paper version of this Service Manual, please make a reference to this bulletin on the affected page.
Intake Manifold Installation - Lower
Important: All gasket mating surfaces need to be free of oil and foreign material. Use GM P/N 12346139 (in Canada, use GM P/N 10953463) or the equivalent to clean surfaces.
1.Install the intake manifold gaskets.

2.Apply small drops (8-10 mm [0.31-0.39 in]) of RTV sealer, GM P/N 12346286 (in Canada, use GM P/N 10953476) or the equivalent to the four corners of the intake manifold to block joint (1).
3.Connect the small drops with a bead of RTV sealer that is between 8-10 mm (0.31-0.39 in) wide and 3.0-5.0 mm (0.12-0.20 in) thick (2).
The remaining steps on the original bulletin remain unchanged.

[jetta90]

Thank you folks for the reply.
I was going to start putting it back together today but the oring the parts store ordered isn't the one that belongs on the oil pump shaft. So much for well laid out plans.
Look like all I need to do to install the oil pump shaft unit is ensure the gear drive teeth mesh and that the vertical "hexagon" shaft enters and engages into the bottom of the oil pump shaft.
I couldn't see where the other end of the "hexagon" shaft connects to, but I would guess it engages into the oil pump itself somewhere deep in the block?
You guys have been a great help. Thank you again.

[Colt Hero]

When I did my gaskets in May, the oil pump drive unit came out with the hex shaft still attached to it. I just popped on the new O-Ring and dropped the whole thing right back in. From what I had read, it didn't matter how this thing went back in. It wasn't a position-sensitive thing like a distributor (and apparently this was true - unless I got incredibly lucky). Anyway, it didn't seat all the way in initially, and I turned and jiggled it a bit for a few minutes until it finally dropped all the way in. Then, I just tightened the bolt to the proper torque. This was the only part of the project where I almost had a big problem. A friend stopped by right at the moment where I was removing the single bolt on the clamp holding the pump drive. He distracted me enough that the metal clamping bracket ended up slipping down into some crevice of the car's frame!!! It didn't hit the ground and I couldn't see where it was (and I couldn't get underneath the car with no way to start it). I was about to lose a lot of time trying to jack the car up high enough to place it on either jackstands or (better) ramps, when I decided to try fishing a coathanger in there. Took probably 30-40 minutes, but the bracket finally dislodged and fell to the ground. Thank God!