Turbo shaft play... how much is too much?

[RussJ]

My truck's been acting different lately, so taking the advice of others, I checked a few things. The problem that I found is some turbo shaft play. My question is this, how much is too much? What is the best way to check (preferably without removing the turbo)? Just grabbing it with my fingers there is some side to side and a little up and down play. There may be some wear on the inlet housing. I say "may" because it could be wear or it could have been machined that way. I'm not sure how to post pics or I would. Any ideas?

 

[Bob4x4]

from the factory... ... ... .

INSPECTION

Visually inspect the turbocharger and exhaust manifold gasket surfaces. Replace stripped or eroded mounting studs.



Visually inspect the turbocharger for cracks. The following cracks are NOT acceptable:

Cracks in the turbine and compressor housing that go completely through.

Cracks in the mounting flange that are longer than 15 mm (0. 6 in. ).

Cracks in the mounting flange that intersect bolt through-holes.

Two (2) Cracks in the mounting flange that are closer than 6. 4 mm (0. 25 in. ) together.

Visually inspect the impeller and compressor wheel fins for nicks, cracks, or chips. Note: Some impellers may have a factory placed paint mark which, after normal operation, appears to be a crack. Remove this mark with a suitable solvent to verify that it is not a crack.

Visually inspect the turbocharger compressor housing for an impeller rubbing condition (Inspect Compressor Housing for Impeller Rubbing Condition). Replace the turbocharger if the condition exists.

Measure the turbocharger axial end play:

Install a dial indicator as shown in (Measure Turbocharger Axial End Play). Zero the indicator at one end of travel.

Move the impeller shaft fore and aft and record the measurement. Allowable end play is 0. 026 mm (0. 0001 in. ) MIN. and 0. 127 mm (0. 005 in. ) MAX. If the recorded measurement falls outside these parameters, replace the turbocharger assembly.

Measure the turbocharger bearing radial clearance:

Insert a narrow blade or wire style feeler gauge between the compressor wheel and the housing (Measure Turbocharger Bearing Radial Clearance).

Gently push the compressor wheel toward the housing and record the clearance.

With the feeler gauge in the same location, gently push the compressor wheel away from the housing and again record the clearance.

Subtract the smaller clearance from the larger clearance. This is the radial bearing clearance.

Allowable radial bearing clearance is 0. 33 mm (0. 013 in. ) MIN. and 0. 50 mm (0. 020 in. ) MAX. If the recorded measurement falls outside these specifications, replace the turbocharger assembly.



Bob

 

[jwilliams3]

Basically look for oil leaks (in liquid form).

Measuring play you generally want no more than . 020" radial play (side to side) (that also covers up down )

On a Holset you want NO axial play (in/out) with the shaft.



If the compressor wheel has been rubbing the compressor housing on its own then the turbo needs rebuilt (basically).

 

[RussJ]

The "wear" I saw came off on my finger, so although it looked serious, it turned out to be a very light oil or grease film. It was about 1/8th inch wide, just outside of the impeller blades.

I borrowed a dial indicator from my father, but hav'nt found time to measure yet, hopefully tommorrow. Can you measure the side to side play with a normal feeler guage or do I need something else. All I do know is that I can feel the play in the shaft with just my hand. Only side to side, not in and out.

I am not even sure if this is the root of my problems, but I am darn sure concerned with the tolerances/overall condition of my turbo.

My money is presently being saved for a clutch and fuel system, a new turbo was still a ways down the road!

 

[Bob4x4]

A feeler gauge will get you close enough.



Bob

 

[RussJ]

Well I got out the feeler guage this evening and it turns out I have about

. 015 inch axial play. Well withen specs. I could'nt believe that as much as the impeller moved by hand, it turned out to be so little once measured. Oh well, it's good to know the turbo's okay after all!

On the other hand, if that was'nt the problem then what is? I guess my focus must now turn to the fuel system. Hopefully this weekend I will be able to check out the FCA, but how do you check the rail relief valve?

Thanks for the help so far everyone!