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Thread: Turbos with ZERO! shaft play.

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Posts: 1-10 of 19
2009-04-20 13:18:07
Turbos with ZERO! shaft play.
Radial play: While looking directly at the end of the shaft (either compressor or exducer side) you can move it up, down, left and right.

Axial play (end play): While looking directly at the end of the shaft you can move it in and out.

I've read so many for sale threads about turbos with zero shaft play that I assumed there existed turbos with zero shaft play.

Finally after having dealt with many new and used turbos I can finally weigh in on the subject.

No turbos have zero shaft play. They actually come with quite a bit of radial shaft play when new. It may be less noticeable in a new turbo without any miles on it, but even pumping oil through it once will make the radial shaft play obvious and significant. This play is by design, and nothing to worry about (and goes away almost completely with oil flowing through the bearing). I didn't know this until experiencing it for myself. I was worried some used turbos we had were in trouble until I realized the new turbos were the same and all journal bearings/ball bearings have radial play from the get-go.

Axial play is almost non-existent on a new or well taken care of used turbo. Is this what people are talking about when they advertise a turbo with ZERO! shaft play? It must be, because I guarantee you they have radial shaft play, and quite a bit of it.

If you do have a turbo with no shaft play, it is likely seized.

That is all.
2009-04-20 13:51:24
Someone finally posted this

I know in my personal dealings, I always indicate "minimal/no shaft play" by the axial play. Axial play, IMO, is the killer.

Should have radial play, as when the oil pressure builds in the cartridge, it forms a barrier and that's why your wheels need to be balanced. Once the turbine starts to spool, if it's out of balance, it runs the possibility of coming into contact with either housing when at speed, which is obviously not good. Think of the wheels on the shaft as floating, when in operation.

Now, if you take the above into consideration, and end up with lots of axial play, the wheels on the shaft can actually shift and cause themselves to lose balance (even though balanced) and come into contact with either housing and damage themselves, or cause the shaft to come into contact with the bearing (either thrust or ball) and damage the shaft/bearing etc.

I personally look at it like a wheel that's been balanced on your car, but the hub bearing is shot. Runs fine radially, but if you have too much axial movement, it could end up running out the assembly and you'd end up with a possible mess on your hands. May not be the best analogy, but I've seen some pretty nasty things happen, so it fit for my recollection.
2009-04-20 18:41:01
2009-04-20 19:09:02
You say duh, but I see turbos for sale right now that say they have no shaft play. They are all over the Internets. I guess it was obvious? Thanks for cluing me in earlier.
2009-04-20 19:20:04
I just always assume everyone is lieing, or doesn't have a clue.
2009-04-20 19:21:45
maybe they should word it.......no obvious shaft play???
2009-04-20 19:25:55
Or acceptable garrett shaftplay. They come with enough from the factory LOL.
2009-04-20 19:33:32
Originally Posted by tomaz1684
maybe they should word it.......no obvious shaft play???
If your turbo doesn't have obvious shaft play it's broken.
2009-04-20 19:34:47
Originally Posted by Ken's
I just always assume everyone is lieing, or doesn't have a clue.
That's what I'm leaning towards.
2009-04-20 19:47:50
Originally Posted by BenFenner
That's what I'm leaning towards.

Well maybe I should start calling your CPT. Obvious!
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