Has anyone replaced their balance shaft bearings on a 3RZ?

[eurasiaoverland]

Hi

Just want to start by saying I am not interested in doing a balance shaft delete. At all.

I've stripped my 3RZ right back for a re-bore due to cylinder wall damage from a dropped valve. I pulled the balance shafts and notice that one of the bearings looks a little worn.

I've found a couple of places which sell new sets of balance shaft bearings:

Toyota 3RZ 2.7L Balance Shaft Bearing Set

https://www.ericsperformanceparts.com/home.php?cat=259

Has anyone changed their balance shaft bearings??

Thanks!

 

[Konkordmusk]

Should be able to do the job easily with a camshaft bearing removal/install tool, but you may already know that.
If there WAS severe damage to the bearing, I would say mic and check the bearing surfaces and see if they're alright. But as you said, its minor damage and is probably fine.

 

[eurasiaoverland]

Thanks for your reply.

The rear bearing on the RH balance shaft is dark from wear, and both balance shafts are slightly scored rotationally. I doubt this is really a problem, but new balance shafts are cheap so I was thinking just to replace the whole lot.

OTOH, given that the balance shafts receive no loading they can probably get away with a bit more oil clearance than standard. There is no detectable play in them.

 

[Konkordmusk]

I see three options here, one which you've already mentioned which is to get new balance shafts.
The other would be to take the current ones to a machinist and have him mill the bearing surface and mic to see if OE replacement bearings will work or if you should go with oversize bearings.
The third is just to install the new bearings on the current shafts.
If you say they're only slightly scored, I would just install new bearings and call it a day. Maybe some emery cloth love on the scored surface.

 

[eurasiaoverland]

Engine was very poorly maintained and had drit ingress through an unsealed oil pan. I'm going with 2x new balance shafts and a new set of bearings.

LCE Performance do a specially made bearing installer / remover for $25. Think I'll just give the bearings and tool to the machine shop to get in.

3RZ Balance Shaft Bearing Remove & Install Tool