d_jabsd
d_jabsd Reader
10/3/20 6:12 p.m.

I bought a used SR20 (GT2560) to install in my 94 Miata.  the wheel doesn't spin freely.  it spins with giving pressure, but i can't just flick it and have it spin until it stops.  is this normal, or should i rebuild?

spandak
spandak HalfDork
10/3/20 6:30 p.m.

If I remember on my last one it would spin freely but I don't think I was like a top. It wasn't a ball bearing so that makes sense. 
Probably worth a check. I paid a local shop less than $100 to replace the turbo seals and balance it. 

frenchyd
frenchyd PowerDork
10/3/20 7:03 p.m.

In reply to d_jabsd :

Take a magic marker Mark one blade and the housing adjacent. Spin it and mark where it stops. Do it several times. Marking each spot. If you notice a pattern  the bearings need work. If it's random you're probably good to go. 

BoxheadTim (Forum Supporter)
BoxheadTim (Forum Supporter) MegaDork
10/3/20 7:22 p.m.

How long since the turbo has been on a running engine? Could it just be total lack of lubrication and/or caked up oil in the cartridge?

Any shaft play?

rustomatic
rustomatic Reader
10/4/20 1:44 p.m.

That's definitely not ideal.  Housing should be clean (inside), wheel should spin effortlessly, and there should be no shaft play.  Even my 23 year-old Holset HX meets these marks . . .

d_jabsd
d_jabsd Reader
10/4/20 6:07 p.m.
BoxheadTim (Forum Supporter) said:

How long since the turbo has been on a running engine? Could it just be total lack of lubrication and/or caked up oil in the cartridge?

Any shaft play?

no shaft play at all. no gritty /scraping sounds no binding at certain points to indicate a bent shaft. if i had to guess it hasn't been in a car in a while.  maybe i'll just pic up a rebuild kit and tear into it.  get everything cleaned up. 

d_jabsd
d_jabsd Reader
10/4/20 6:11 p.m.
rustomatic said:

That's definitely not ideal.  Housing should be clean (inside), wheel should spin effortlessly, and there should be no shaft play.  Even my 23 year-old Holset HX meets these marks . . .

it will spin, but only do a partial rotation.  it does look like there is oil on the turbine side.  i'm going to rebuild it to be safe.  

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
10/4/20 9:06 p.m.

What is peoples' definition of "no shaft play"?

Every turbo I have ever fondled had a decent amount of radial play, because there was no oil pressure to keep the journal bearings apart.  Having a LACK of play would seem to indicate a problem.

 

I always went by the rule of thumb that if you couldn't make the compressor wheel contact the housing, the turbo bearings weren't worn out.

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