Intermediate Shaft Bearings

[Nohawkscott]

My machine shop guy just told me that they pulled the oil pump shaft and bearings out of my block in order to vat the block. This is something I really didn’t think would need to happen since we discussed leaving these bearings in place and using his non-caustic cabinet to clean the block.

I’m not opposed to replacing these bearings but I had been told it wasn’t a can of worms worth opening, now he’s telling me he’ll just reinstall the old bearings since they still look good??

is there any particular insights regarding this shaft and bearings I should share with him? This shop see’s mostly domestic stuff so they might not be completely aware of potential issues with just driving some bearings back in..

or maybe I’m overthinking this?

[digger]

i think they are "line" reamed from factory so if you remove them they will likely not go in concentric anymore so you're probably better to replace (especially if they are not ultra low mileage) and have them line bored and honed in situ once they are pressed in.

[Nohawkscott]

Does this sound about right?

[digger]

I have seen that process mentioned before and it apparently works ok but it isn't how i would do it as a first option (i would have it line bored to size after pressing in if they have equipment to do so and then hone. Since it is a flexible sleeve so not guaranteed to be perfectly concentric after pressing it in an honing it wont correct that). In any case the shop should be able to tell you what to do as they are supposed to be the experts. There usually multiple ways to skin the cat

[Nohawkscott]

That makes sense to me digger. I’ll get some new bearings ordered and talk to the machinist tomorrow about their plan.

In your experience is it a normal scope of work to replace these bearings during a rebuild if an M20 or are the originals usually left in place?

[digger]

That makes sense to me digger. I’ll get some new bearings ordered and talk to the machinist tomorrow about their plan.

In your experience is it a normal scope of work to replace these bearings during a rebuild if an M20 or are the originals usually left in place?

Normally left in place if they are in good condition but given the age and mileage these things are hitting there does seem to be issues with them flaking away from fatigue so these threads do pop up every few months