Jump to content
SAU Community

Turbo Shaft Play...

Samon

By Samon,
in Engines & Forced Induction

 Share

Recommended Posts

Samon Proficient

Samon

Posted
Posted

Hello all,

My first post (I think... maybe not) over in the 'dark-side' of the forums...

I'm about to do the big RB25DE => RB25DE+T conversion, and I'm pretty sure I've got everything I need... only worry I have is with the turbo itself. It's a stock R33 RB25DET one, but there's a little bit of shaft-play. I've heard that it's okay to have a little bit of up/down movement, but no back/forwards (I guess you'd call it 'end-play' or something)... is this right? It moves about 3mm back and forwards... is it worth getting it re-built? What kinda prices am I looking at for that? I've done plenty of searching, but can only really find threads related to 'items for sale' adverting 'no-shaft-play' or 'minimum shaft-play' so far!

Cheers,

Sam.

Link to comment
https://www.sau.com.au/forums/topic/221097-turbo-shaft-play/
Share on other sites
Samon Proficient

Samon

Posted
  • Author
Posted
so your facing the wheel and you can pull it up and down or your facing the wheel and can move it side to side with 3mm of play?

if second one then yes its rooted.

If I look directly into where the dump-pipe bolts on, i can slide it... in-and-out about 3mm

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

Better than moving side to side? wtf?

Side to side is perfectly OK, every single turbo will have S-2-S movement even for a ball bearing turbo. Bush bearings move substantially more.

When the car is on, running with oil pressure this movement is taken up by the oil in the cartridge.

Front to back (or in and out) is the BAD movement of the lot.

Samon Proficient

Samon

Posted
  • Author
Posted
Better than moving side to side? wtf?

Side to side is perfectly OK, every single turbo will have S-2-S movement even for a ball bearing turbo. Bush bearings move substantially more.

When the car is on, running with oil pressure this movement is taken up by the oil in the cartridge.

Front to back (or in and out) is the BAD movement of the lot.

That's the impression I was under. I'll have to have a look at it tonight when I get home, but how much movement (in and out) is okay?

Kinks Grand Master

Kinks

Posted
Posted
Better than moving side to side? wtf?

Side to side is perfectly OK, every single turbo will have S-2-S movement even for a ball bearing turbo. Bush bearings move substantially more.

When the car is on, running with oil pressure this movement is taken up by the oil in the cartridge.

Front to back (or in and out) is the BAD movement of the lot.

From what I have picked up over the years, in a bush bearing turbo any axial (front to back, in and out) movement is bad because it means the thrust washer has worn out. Some radial movement is OK. In a ball bearing turbo, a very small amount of axial movement is OK. Radial movement is a bad sign.

That said, a friend's brand new ball bearing HKS turbo had about 3x more radial play than the stock item we took off. I was quite surprised but I guess they run wider clearances as part of the design.

Plenty of disclaimer on the above though, I have done 2 turbo swaps myself but never one due to imminent failure :down:

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

The new turbo = no oil in it.

Turbo taken off car = some oil to pickup the slack.

Turbo off a car, same model etc probably should have less play (except if its worn and so on)

I've had my turbo's off, bush bearing, had a bit of play, same with my GT30

So one of each type, and both had side-t-side, the GT30 had less... but then we are talking MM here so its minimal overall

Samon Proficient

Samon

Posted
  • Author
Posted
The new turbo = no oil in it.

Turbo taken off car = some oil to pickup the slack.

Turbo off a car, same model etc probably should have less play (except if its worn and so on)

I've had my turbo's off, bush bearing, had a bit of play, same with my GT30

So one of each type, and both had side-t-side, the GT30 had less... but then we are talking MM here so its minimal overall

Just had another look, much closer this time, and in reality we're talking about less than 1mm in/out play. This should be fine, right?

nizmonut Community Regular

nizmonut

Posted
Posted (edited)

i was reading manufacturers manual the other day and browsed past this particular subject, factory manual says ideal maximum forward to back movement or thrust should be .8 of a millimeter.

Edited by nizmonut

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Duncan
      RB26DETT Sketchy boost mod?

      By Duncan · Posted

      Manual boost controllers (where a little of the boost was bled off) were quite common back in the day, because they were cheap and easy. Generally they had a manual adjustment screw rather than being fixed like yours. Down side is they always bleed boost, not just when you want them to so an electronic boost controller that uses a solenoid will have less lag.
    • nash47
      Cas issue

      By nash47 · Posted

      Hello , im new here and i have A31 home build  RB25det neo stock eng / turbo  aem ems 2 blue connector  aem 3.5 map aem cas disk aem wideband connected to ecu  355 lph pump 550 nismo yellow injectors side feed aftermarket regulator  and won’t start with base aem tuner basic tune eventually flipped cas 180 degree so it triggers on correct stroke not in exhaust cycle  Now it won’t start Wideband reads 10 and 11 at lowest fuel setting  and will share calibrations soon for aem tuner i think something is wrong in aem tuner    please if you have any information, am very grateful         
    • nxh
      R34 4 door side skirt identification

      By nxh · Posted

      Legend. I ended up finding the facebook account of the owner of the first car i sent but sadly he deactivated the account. I think you’re right in saying it’s some sort of well done custom job. Really appreciate your help anyways.
    • GTSBoy
      boost source Size Garrett gt28 gen2

      By GTSBoy · Posted

      Totally equivalent. Stock often goes from the comp cover because that's where the actuator is also installed and the factory needs 2" of hose to make the connection - and it comes as a pre-assembled unit. They totally have a boost reference from somewhere between the turbo and the throttle(s). Oh, jeez. Just do it in M12 then. We don't actually care that much. I would expect any such AN converter fitting to rely on an o-ring or some other seal onto a flat surface under the flange of the hex**, because bolt threads are no intended to provide a pressure seal. unlike..... pipe threads. **which also requires a suitably flat and smooth surface on the turbo's boss to provide the seal.
    • timmy94
      boost source Size Garrett gt28 gen2

      By timmy94 · Posted

      I also used NP   That’s were it’s seems to be the best place to fit it? All schematic shows also that it’s should be referenced from the turbo housing. But idk, I do see high hp cars without any connection or anything to their turbos, so I really don’t know how they connect their things
×
×
  • Create New...