oil pump drive gear wont fit!!!

TooGoode

rediculous DD
Mar 1, 2007
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argh i bough a supra from noredline. the motor was completely rebuilt but is in short block form still. i went to install the oil pump drive gear and it wont fit!! is there a difference in years as far as the size of the bearings? the bearing looks original in the motor where the shaft sits but is a little too small and the shaft wont go in........
 

Poodles

I play with fire
Jul 22, 2006
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Is that oil pump drive from that engine?

If not, it more than likely won't fit, it will have to be resized for the bearings...
 

p5150

ASE and FAA A&P Certified
Mar 31, 2005
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Central Idaho
I assume you are talking about the oil pump drive shaft. Chances are it just needs to be polished. The tolerance is very tight in there and the slightest bit of roughness wont let it in.

I had the same problem. It wouldnt go in until I polished the shaft
 

TooGoode

rediculous DD
Mar 1, 2007
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what i ended up doing was atatching the shaft to a drill press and turning it on then going over the journals with 800 grit for a little while....it fits!!
 

Jaguar_5

It's ALIVE!
Feb 7, 2006
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Hmm... I don't know if that was the best idea...

I'm not an expert but i have a feeling that will leave scratches on it, personally I wouldn't do it, not to mention you are just guessing on the clearances
 

gaboonviper85

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Jan 13, 2008
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Jaguar_5;1072402 said:
Hmm... I don't know if that was the best idea...

I'm not an expert but i have a feeling that will leave scratches on it, personally I wouldn't do it, not to mention you are just guessing on the clearances

800 grit is extreamly fine shit!!! That shaft would have an almost mirror finish if he used oil with sandpaper...

Bet he removed .0005" of material at the most.



To the OP...how is the fit??....did it slip right in or did you still have to play with it till it finally went in?....is there any side to side play?
 

TooGoode

rediculous DD
Mar 1, 2007
549
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Chandler, Arizona
it was a mirror finish as fuck......i had to play with it a little to go in but once it was in it had no play whatsoever and was snug while still able to spin.....
gaboonviper85;1072620 said:
800 grit is extreamly fine shit!!! That shaft would have an almost mirror finish if he used oil with sandpaper...

Bet he removed .0005" of material at the most.



To the OP...how is the fit??....did it slip right in or did you still have to play with it till it finally went in?....is there any side to side play?
 

Poodles

I play with fire
Jul 22, 2006
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A screwup here will cost you the motor...

If the oil pump drive siezes, the engine starves of oil and it's goodbye motor...
 

Jaguar_5

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Feb 7, 2006
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gaboonviper85;1072620 said:
800 grit is extreamly fine shit!!! That shaft would have an almost mirror finish if he used oil with sandpaper...

Bet he removed .0005" of material at the most.

Like I said, I'm no expert, but I was thinking more on the lines of microscopic scratches, and being perfectly round & level...

I was just throwing my .02 in ;)
 

gaboonviper85

Supramania Contributor
Jan 13, 2008
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Jaguar_5;1072781 said:
Like I said, I'm no expert, but I was thinking more on the lines of microscopic scratches, and being perfectly round & level...

I was just throwing my .02 in ;)

microscopic scratches won't hurt a thing....a glass mirror has microscopic scratches....

Its damn near impossible to remove imperfections from metal (I'm a machinist)....if he used 800 grit paper then he probably improved the bearing surface better then factory....although he should have mic'd it to give proper tolerances cause when the motor heats up that shaft is going to expand and probably wipe that bearing out...

So.....I recomend you remove it and have a machinist mic the ID of that bearing and mic the OD of that shaft and see if it is within trsm spec!


But if he kinda had to finagle that shaft in the I have a feeling its about .002" fit....what is the trsm spec on that fit.
 

gaboonviper85

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Jan 13, 2008
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Poodles;1072690 said:
A screwup here will cost you the motor...

If the oil pump drive siezes, the engine starves of oil and it's goodbye motor...

doubt that will happen....if I'm not mistaken its a brass bearing correct?.....he will just wipe it out and blow the oil seal....then have a mess to clean up but I don't think it will stop the pump from pumping...still not good though!!!