Oil pump drive worm gear orientation?

[Datsun 1600 Nut]

Hi guys,

Can anybody here confirm which way around the worm gear must be installed on the crank?

I have recently built my L18 and have started worrying that I have installed the worm gear the wrong way around on the crank.

All of my FSM's do not specify the orientation of the gear sufficiently, and I can't exactly remember which way around I installed it. One side has a fairly large chamfer on it, and it seems that the gear teeth are offset to on side?



What consequences are there to installing this gear the wrong way around?

Any help will be appreciated.

Thanks.
Jared

[Three B's Racing]

Installed with the dimple for the timing chains bright link facing outward.

[Three B's Racing]

Oh SHIT!! I was thinking crank timing gear sorry doh!!! Look for witness marks on the mating face from the oil slinger.

[okayfine]

Ah, the good ol' oil slinger, another thing that can go on two ways, but only one is correct. Ask me how I know.

[datzenmike]

Spindle drive gear,.... I don't think it matters. Turns the same way either direction you install. Look at the closest tooth location above the key way. Now turn backwards... tooth in same location.

[defdes]

Like a nut will thread onto a bolt either way.

[abisel]

I believe the side with the chamfer goes inboard toward the engine to fit over the crankshaft fillet.

[Chickenman]

I believe the side with the champher goes inboard toward the engine to fit over the crankshaft fillet.

Correct orientation, but toothed crank gear goes on first. Champher on worm drive gear should face crank gear. BTW, that looks like a very early L16 worm gear with shoulders. Brass gear had shoulders as well. Later versions ( L18, L20B and L24 > ) were symmetrical in shape with no shoulders.

Picture of later style worm gear with champher facing crank gear:

[Datsun 1600 Nut]

Thanks for the help guys.

I pulled the front cover seal out and pulled the gear and had indeed installed it with the chamfer towards the crank pulley.

I have the later style worm gear as depicted in Chickenman's post above and not the one in the photo in my original post.

I did not notice any change in the position of the dizzy shaft at TDC when installing the gear in either direction but have left it with the chamfer facing the timing chain for peace of mind.

[Chickenman]

Peace of mind is always good.

BTW, the one in your first post was only used on early L16's. The shoulders were different offsets. I believe this style only came on early L16's ( 1968 and perhaps early production 1969's ). It is steel and not Brass. That style defiantly makes a difference which way you install it. Mesh will be off center if installed backwards.

The later style could probably be installed either way and work..... but ONLY if brand new worm and spindle gears are used. Once the gears " bed-in " they must be re-assembled eaxactly the same way. The Champher makes it easier to slide over the end of the crankshaft and is used for proper orientation.