front cover/oil pump stub shaft

[Calan]

I started cleaning and inspecting various parts for my new engine build tonight, and want to get some advice on the front cover.

The cover and oil pump gears look to be in good shape. There is no play or wear on the gears, but the end of the stub shaft is chewed up where you put a wrench on the back side to hold the oil pump sprocket. There is some very slight "grooving" for lack of a better word on the stub shaft as well...but it is very slight; you can barely see or feel it. The cover has the BS removal freeze plug in it, and the two seals, pump sprocket, and castle nut were replaced with new OEM ones about 5-6k miles ago.

I'll try to get some pics posted, but in the mean time:

1. Can I buy just the stub shaft somewhere?

EDIT: Answered this one myself; found the Mirage shaft with the oil groove

2. Do you think the front cover is still good? The seals still look look and feel new, with no visible wear (I'll replace them though anyway if I keep this cover). If anything, I may want to replace the back gear cover (is it available separately?), but I don't think the slight wear from the stub shaft is even worth that.

3. There is no lateral play that I can detect in the gears, and VERY slight thrust wear visible on the cover. There is a slight bit of in/out play, but I think that is normal? Does anyone have the go/no-go numbers handy for the oil pump?

I really don't want to sink $300 into a new cover/oil pump, but obviously I don't want to take any unnecessary risks with my new motor either.

Are the topline kits from Extreme PSI any good? (Also, they don't show any gears in the pic).

Thanks guys...

Craig

 

[Calan]

Pics (sorry...best I can do at the moment):

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[Zex4g63]

I generally just buy a new set of gears from JNZ and reuse the cover so long as the engine did not have a major failure before. I then polish the rear cover on a piece of granite with sandpaper to remove the scratches and make it flat. After that I make sure that it has the reasonable clearances as per the manual.

 

[woooop]

Buy new and OEM not topline or ebay trust me. I gess you have to ask your self how important is my motor and car, if you dont care go cheep.

 

[Calan]

Does anyone have the factory clearances handy? The gears look to have barely any wear at all.

BTW - I believe this cover/pump only has about 15-20k on it.

 

[AndrewD5418]

Buy new and OEM not topline or ebay trust me. I gess you have to ask your self how important is my motor and car, if you dont care go cheep.

There is somebody on ebay that sells OEM but for cheap..

 

[Zex4g63]

Does anyone have the factory clearances handy? The gears look to have barely any wear at all.

BTW - I believe this cover/pump only has about 15-20k on it.

Oil pump side clearance
Metric Standard
Drive gear 0.08-0.14(.0031-.0055)
Driven Gear 0.06-0.12(.0024-.0047)

 

[Calan]

That is from the gear to the side of the housing/front cover?

Thanks much

 

[lacroixdp]

Buy new and OEM not topline or ebay trust me. I gess you have to ask your self how important is my motor and car, if you dont care go cheep.

This is absolute rubbish. I've used aftermarket oil pumps before with no ill effects whatsoever (as have many other people on here *I have seen a few cheap-o's from ebay lock up however - that's why you order from a reputable vendor*). A great example of good aftermarket parts that immediately comes to mind is Parts Dinosaur. I prefer OEM sure, but it's misleading to make such a blanket statement when in fact aftermarket parts are just fine for most applications. It's a great way to fix your car if you're on a tight budget.

 

[big_d]

^^^ I agree, I use the bsek that parts dinosaur sells on my beater dsm and it has been flawless for about 8k miles. The motor was also put together with a full ebay gasket kit with arps and a cometic head gasket and it has yet to leak a drop of anything. People have different experiences with different products, you make the decision.

 

[dsm-onster]

Oil pump side clearance
Metric Standard
Drive gear 0.08-0.14(.0031-.0055)
Driven Gear 0.06-0.12(.0024-.0047)

I see that Craig has the 7bolt gears. And those numbers are from the 2g manual. The 6bolt gear teeth are straight cut. Does the above apply to all block variations?
EDIT: nevermind. I just looked it up in my 6bolt overhaul manual and it shows the same tolerances. If 2g and 6bolt are the same, the 1g 7bolt should be the same.


Craig, I'd run it. The oem oil pump is tough and reliable. From my experience it can see some real issues before it should be something you replace. I've used a oem oil pump with slight in and out play for several thousand miles and really beat on the car. In fact I don't think I've touched an oem oil pump with out some lateral play. I've rebuild a few 4g63s over the years (none due to an oil pump failure ). It's my opinion, but if lateral play were a concern, the service manual would have put in limits. I'd run it.

 

[Calan]

Thanks Matt. That's what I'm thinking as well.

I looked it over really good again last night, and it looks fine. The only thing that gave me even a slight concern was very fine wear grooves in the housing where the stub shaft rides; but they are almost imperceptable. If I remember correctly, my cam caps have had more wear than this every time I've looked at them

I'm gonna pick up a new stub shaft and seals (which I felt bad about taking out, since they were still like new after only 5k or so; but better safe than sorry)... and run the hell out of it.

 

[TOONAH]

I would just like to add that I had some serious concerns about the stubby shaft scenario.
I did create a new post some time ago regarding this possibly critical component.
There are two types of stubby shaft available. The Mitsubishi oem one has a groove around the circumference of the o.d. of the shaft, exactly where the oil feed hole is in the pump gear. The other type such as the PCI one that Parts Dinosaur sells, does not have this groove. After much debate with other DSM enthusiasts, I came to the conclusion that using the PCI type is risky. Some members here replied to my post that the non-grooved type do not receive proper lubrication and can seize up the oil pump. Also they tend to be not well balanced. The bolt hole might be a few thousandths off center and the shaft will wobble adding stress to the oil pump gears.
I had already installed a PCI type in my 7 bolt project engine. I had the motor ready to go back in and was loathe to tear the motor apart, especially pulling the oil pump back off, since I used copper adhesive on the gasket.
After much thought I realized that the stubby might be removed by just taking the oil pan and the front cover off. I had to remove the timing belt and the oil pump sprocket of course. It is easier to remove the castle nut cover for the stubby bolt. I was able to put a long 10 mm open ended wrench beside the crankshaft and engage the flats on the inside end of the stubby. Holding the 10 mm I was able to loosen the stubby bolt. I used a magnetic pick up tool to hold the end of the stubby and pushed it out. I replaced it with the Mitsubishi one with the oil groove. The whole job took less than 2 hours. I feel much better about it now.
I highly recommend to all of you not to use the stubby without the oil groove. The groove fills up with oil and is centrifuged to the stubby shaft journal surfaces, providing far greater
lubrication of both ends of the shaft than the non-grooved design. Stick with Mitsubishi (DSM) designs where ever possible. A lot of after market manufacturers cut corners to save money. The new oil pump I bought from Parts Dinosaur looks great. I have bought many parts off them. This is a design issue, not a problem for Parts Dinosaur. I continue to buy parts from them. I have suggested to them that they stock the OEM Mitsu stubby instead.
Hope this helps clear up any doubts about which Stubby to use.