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Merc Inboard 454 Gen VI Flywheel issue?

R

redhook98

New member
Good morning all! I had my port motor in my 38-ft carver blow back in July. Ordered a rebuilt GenIV, but they ended up sending me a Service Replacement (Gen VI with fuel pump boss). The flywheel and harmonic balancer are not the same. have a brand new balancer on the way, but been struggling with the flywheel. Finally bought one off of Ebay for a GenV/VI and it arrived yesterday. Just occurred to me that it is most likely for a sterndrive though. Part number is 10101171. I have heard of people removing the 168-tooth ring, heating it and installing on the other side of the flywheel. How difficult is this? Is a 10101171 for a sterndrive? Or inboard? Hard to find info. Thanks!
 
I believe so.
If it is machined on through, take it to a machine shop.
They will be able to heat the ring gear (not red HOT) on a turn-table, and gently spin it as they drive it into the required position.

But again..... not red hot!
 
If the 10101171 is machined on through (see A below) ...... you should be able to re-position the ring gear.
If like B below, perhaps it can be machined on through, and then set in position.

GM flywheel ring gear position.jpg
 
I put the flywheel in the freezer first, the thermal mass keeps cold as you heat the ring......it takes hardly any heat. The install goes faster too.....much less heat required. I don't want to heat the ring gear any more than necessary, the material in the ring gear will respond negatively to excessive heat. By freezing that large thermal mass, it takes very little heat to accomplish the flip.

Ps. Managed and worked a machine shop with my brother for years here in Duluth MN. This advice is coming from practical experience.
 
Last edited:
timguy said:
I put the flywheel in the freezer first, the thermal mass keeps cold as you heat the ring......it takes hardly any heat. The install goes faster too.....much less heat required. I don't want to heat the ring gear any more than necessary, the material in the ring gear will respond negatively to excessive heat. By freezing that large thermal mass, it takes very little heat to accomplish the flip.

Ps. Managed and worked a machine shop with my brother for years here in Duluth MN. This advice is coming from practical experience.
Click to expand...


The OP's issue has been the location of the ring gear.
The new flywheel that he received has the ring gear positioned for an I/O scenario (i.e., FWD).
He apparently has an I/B of which requires the ring gear to be positioned towards the face of the flywheel.

As for bringing the temperature down..... that is great if you have the time to do so.
Most machine shops are not going to do that.
They are going to use a turn-table, spin the flywheel, apply heat, tap the ring gear off, etc.

And you are absolutely correct regarding the amount of heat applied to the ring gear.
Un-even Red Hot will disrupt the hardening and will cause eventual failure.
 
Excellent Rick, been in Portland 3 times. Moved my sister out in 79, she bailed after St. Helens. I loved it out there. May go back to visit some friends next summer......I'm semi retired now. Still building some hot rod engines at home. Love the Chevy 327's 350's 400's, 427's and 454's. Ford FE's.....beautiful exhaust note and torque. Rebuilt a 1970 Chris Craft inboard 327 ski boat with Paragon drive. Made some performance mods. Performance was breathtaking. They only made a few of them, most had 307's I think.
 
Thanks everyone. Ended up just buying a brand new one from Michigan Motorz. Tired of sending good money after bad. Now I have a harmonic balancer issue. Separate thread.
 
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