Oil pump gear swaps

[spyderdrifter]

I'm just looking around for info, but not planning on doing this for myself. Will the oil pump gears from a 7 bolt oil pump fit and work in a 6 bolt oil pump? I know 6 bolt gears are spur cut and the 7 bolt ones are helically cut.

 

[gofer]

Way back when I knew nothing about 4g63's I remember helping a buddy assemble a stock build 6-bolt 4g63 that was going in a Colt and we put the 7-bolt helical gears in there.

Moving this from the Newbie forum...

 

[spyderdrifter]

So are you hinting that this would not be the wisest thing to do?

 

[007jimmy]

I believe 90s had straight cut gears and 91+ are helical.

 

[spyderdrifter]

All I've seen are 6 bolt are straight and 7 bolt are helical.

 

[19Eclipse90]

The spur gears show as an early 1G item, both '90 and some '91.

As for the topic, it is possible to swap gears if the clearances check out; people have done it before without issue.

Mitsubishi, however, said it wasn't: Diff. oil pumps? | Galant VR-4 > Technical Discussions | GalantVR-4.org Mitsubishi Galant VR4 Forum. This popped up on the Link forums twice within the past few weeks.

 

[007jimmy]

The spur gears show as an early 1G item, both '90 and some '91.

As for the topic, it is possible to swap gears if the clearances check out; people have done it before without issue.

Mitsubishi, however, said it wasn't: Diff. oil pumps? | Galant VR-4 > Technical Discussions | GalantVR-4.org Mitsubishi Galant VR4 Forum. This popped up on the Link forums twice within the past few weeks.

You are right on the early 91s too. The oil pump drive gear in a 89-91 04.3 is P/N MD121120, and the driven gear is MD125361 (I believe these are the straight cut gears). The late 91-99 regardless of bolt pattern is P/N MD174581 for the drive gear, and MD174582 for the driven gear.

 

[spyderdrifter]

Interesting, engine grenading is always a wise choice Guess I'll make sure my friend uses the spur cut gears then.

I saw this and copied it "Everyone is entitled to their own opinion, but not their own facts." I wish everyone abided by this.