Turbo is off and checking it over. 4 hard years on a Garrett 2860. I've never worked with a ball bearing turbo before. It has more shaft play than seems right. No contact is noticed. Does anyone have a ball park estimate of shaft tolerances?

https://www.turbobygarrett.com/turbo..._bearing_turbo
I found this... but I don't find anything with actual numbers.

 

That's weird. I'm pretty sure garrett had numbers posted somewhere.
how much play does it have that you measured? IIRC if no contact I'd pretty much continue to run it no matter what

 

It measured at .007-.008" It felt like a lot more when I wiggled it by hand. It doesn't matter much as the turbo is not wanting to come off the manifold anyway... every bolt is stuck... and limited room to get a wrench on them securely. Do most just run the miata turbo's until they break?... as they don't seem to lend themselves to disassembly and repair. V-band sure seems like the way to go.

 

Are you positive it's a ball bearing and not a journal bearing turbo? How many bolts are on the center section to exhaust housing? Journal bearing has 4, ball bearing has 5.

 

Sorry to bump an old thread, but this is the most recent one of these I found.

For the garrett bb turbos, it seems that there's some radial play which is fine unless it's making contact with the sides, but any axial play is bad even if it hasn't been run in a while, right?

 

In theory (or writing) but my 2560 had all sorts of play, radial x axial. Didn't scrub anything and worked just fine. Even at 20 psi.

I seem to remember. 006 as listed maximum radial. In the end, I think if it doesn't scrub, it's fine.