New machine shop recommends a line bore due to the middle main bearing being slightly off round. Question for brain trust, how can one verify if it relly needs it or ?

Ps I don't want to repeat the half as- mistake I had with RIMCO again....which turned my 2.0 into a boat anchor

Thanks for your input.

Buy a bore gauge.
Take it to another shop for confirmation, they don't need to be a VW shop, just someone who has a bore gauge and knows how to use it. Just get measurements from them and evaluate for yourself.

I always check regardless, both before and after it comes back from the machinist. With the mag cases (i.e. 2.7L) I get them align-bored after they're shaved as well to make sure the mating surfaces are trued. Aluminum cases don't usually have that issue, but on either, it's also a way to go back to std bearings... at least on the OD and depending on your crank journals for the ID.

If it's a four and get's shaved you'll have the cam bore done as well. On sixes the intermediate-shaft bore get's done... TMI right?

You'll have to send it with the through bolts and torqued properly. The factory docs will have the allowed runout for the bores. Those gauges are expensive so a second opinion is definitely a good idea if you're working with new folks.

Good luck!

Most of these cores need a line bore by now

Guys thanks for reasuring me that I'm not being taken again.

perhaps things have changed but there was some issue sourcing some bearings a while back. std/10 over, std/20 over, etc, feeble memory. measure your crank too. no point paying for a bunch of machine work only to find you can't source what you need to reassemble.

I wouldn't do anything until you have a set of bearings and have the bores sized to the bearings and crank. Type IV take planning.

What was your issue with RIMCO?

I had heard this same thing.

My current case has been done 40 over.....so I think it is done.

I agree with Rick.
See what bearings are actually available before you begin

Rich