oil pump gear confusion

[92nolatist]

Hey guys, I need some help here. Im disassembling my motor for the first time and I got down to the oil pump and noticed, when I took it apart, that the gears inside are helical and my car/motor is an early 92 6 bolt. Now, my question is aren't the 6 bolt oil pump gears supposed to be straight cut?

The motor has 182,000 miles on it and Im replacing just my gears; the case is in perfect condition so Im going to reuse it. This motor has NEVER been taken apart, ever. I bought straight cut gears off extremepsi.com because it said they were for a 6 bolt. So what do I do here, use the new, straight gears or get helical ones?

Thanks,
Dave

 

[kimcheefists]

If you're motor is a 6 bolt, and extreme PSI says the gears are for a 6 bolt, then the straight cut gears'll work. Make sure to get both the drive AND driven gears.

 

[92nolatist]

Thats what i was thinking. And I know about both gears, thanks. But why would there be 7 bolt gears in my car???? Is there a difference between the two as far as oil pressure goes?

 

[bastarddsm]

I have had both straight and helical gears in my late 6 bolts. I was under the impression it was the early (90) 6 bolts that had one type, and late motors had the others.

 

[kimcheefists]

No idea on why you have the helical gears or what the difference in oil pressure is but from what I know about straight cut gears, they're stronger than helical cut gears. The only "bad" thing about straight cut gears are they're more noisy.

 

[92nolatist]

Hmmmm as long as the new gears fit without issue. I could care less about the noise, I honestly like the sound of straight cuts.

Thanks everyone for your help and have a wonderful Thanksgiving!

 

[kthackst]

Make measurements to make sure the gears are the same size. Measure the thickness from one side of the gear to the other.

I had a helical oil pump and put straight cut gears in it and I did get yelled at. One of the DSM gods where I live told me the thickness of the gears is different.

But i havent had any problems yet. So i dont know if it doesnt matter or if I just have a ticking time bomb on my hands