Garret BB turbos, how much play?

[newsh]

Just pulled the GT3071 off my coupe and it has a little play in the shaft. You can hear the bearings when you spin it by hand. Is this normal? I'm wondering if it needs a rebuild already

[Billman]

they cant be rebuilt. You must change the center section if it is damaged (don't know though if what you see is normal or not)!

[Acidburn]

speak to hoffer76 on here, he's had this happen a few times with 3071r's

[Billman]

what pressure did you run with it? Overboost and at the rev limiter.

[Rocco]

3071´s are a **** talking about reliability?

KKK for the win?

Good luck Newsh

[newsh]

I haven't driven it for a year, hard to remember what boost it was running but I think a little less than 2 bar and about 1.7 at the top end. Its a 3B so no overboost. I did have boost creep problems to start with though as I had a small port wastegate on it and it was climbing to 2 bar at high revs. This was on RS2 software so I was actually holding back.. I replaced the WG pretty quickly though and then Mihnea mapped it, in the end we couldn't boost too high in the midrange due to surge..

[Billman]

according to Pauls excel file the 3071 is at 1,7 bar from 6000-7500 well outside the efficiency map. Maybe you overspeed it. Maybe it has nothing and its ok.

[diesel des]

The garret gtr turbos have a lot of play. This is normal. Along as the wheels don't contact the housing they are fine.

[A80Avant]

this is funny how it develops as a thread...

one asks a question about play, then someone will take this for granted and trash the garrett turbos in general, then someone else will come and say its the other way around and garretts are fine etc etc...

best thing to do is to videotape and post the play of the shaft. Those with garrett turbos will be able to judge better that way.

i did about 40K kms with my 3071 bought from 034 and had no issues. run 2.1overboost and around 1.7 to the redline.

there is always a bit of play sideways and in and out of the shaft on the BB garretts

[newsh]

this is funny how it develops as a thread...

Yes, sometimes the only way to avoid confusion is to not ask!

Good idea though, I will make a small video later

I seem to remember it had a bit of play from new so just checking, if it was a KKK it would be fooked..

[Bram]

A little play should be fine. As soon as the engine is running the oil pressure will rise and supports the turbo shaft with some nice oil layer to get it stable. I think Garrett turbos should have less play than a KKK though, due to the dual ball bearing build

[JP]

From experience and not necessarily correct as it is only my experience.

Journal bearing turbo's

Sideplay allowable when journal is dry so long blades dont touch the housing.
Thrust play an absolute nono and requires rebuild


Garret GT turbos

Sound noisy on the bearings on engine shutdown as it carries on spinning
sound noisy as if the bearings have had it when you spin them by hand and they are dry

Can have sideways play so long again the blades dont hit the housing
Can have a surprising amount of thrust play so long the hot side blades dont hit the heat shield


My only other experience with ballbearings is my sons skateboard on which he runs ceramics. For which there are two designs those that achieve maximum spin the quickest and those that go on forever and take little to get them going but just accelerate really slow. When these are clean and freshly lubed up they are noisy bearings with lots of play yet so long we remove the seals and clean them regularly they keep going and going for years providing they haven't been overheated from lack of lubrication. I can only assume that this ballbearing characteristic also applies to turbo's and so long we run filtered clean oil to the turbo and it hasn't been cooked turning into watery p155 then there should be no reason to worry about noise and play providing the initial criteria above are met.

[gnutz2]

My garret BB turbo sounds very rough when it's spun by hand.

Only when the oil is up to temperature it sounds ok.

Also 2 bar is fine right up to redline if you look at the compressor map.

[Billman]

My garret BB turbo sounds very rough when it's spun by hand.

Only when the oil is up to temperature it sounds ok.

Also 2 bar is fine right up to redline if you look at the compressor map.

I have looked at it and our engine is at 2 bar from 5500 RPM outside the compressor map.

[gnutz2]

I work out 2bar on a 2.2l engine with 90% ve at 7000rpm is 52lb/min.

And 2bar at 5500rpm is 40lb/min.

What ve did you use on your calculations?