How do you bend a turbo shaft.?

[matt dunn]

How does a turbo shaft bend without something going through the blades of a turbo?

http://www.youtube.com/watch?v=hmtFa0sz0yE

the front wheel still runs true although there is a more than normal amount of play,
and the shaft is not broken
and there appears to be no chips off the blades or anything,
just what has worn off from rubbing on the housing?

[jondee86]

Overspeed ? Overheat ? Compressor surge ?

Cheers... jondee86

[stolic]

DAMN

I'm guessing sh!t got super hot, and that sh!t melted the other sh!t.
Super hot exhaust gas, failure of turbo cooling? Shaft made of playdoh due to budget cutbacks?
love to see what sort of condition the bearings are in.

[Mr Ree]

I would be interested to see what things look like with the housing removed.

From the axis it appears to be spinning on, I would think the bend has happened between where the shaft leaves the CHRA, and the turbine wheel.

What sort of turbo is it, and was it new or rebuilt?

[matt dunn]

Was a brand new genuine Garrett turbo. GT3076R ball bearing.

It has been on the car almost since we first built the 1800 motor,
so it has done quite a few years of racing,
so it's not like it was faulty from new or made of crap metal or anything like that.

Was on the car and runing fine during qualifying, then did a slow lap mid session to let the tyres cool down,
and when I went to do another quick lap there was no boost.

[Mr Ree]

Oh, in that case, that isnt too bad then all things considered.

I dont know exactly how the Garrett shafts look, but all I can presume is metal fatigue at a point where the shaft thins, caused this issue??

P.S Time for a GTX?

[Bling]

Is that one of those variable geometry turbos?

[RS13]

Overspeed, excessive temperatures/rapid (uneven) cooling, metal fatigue, bearing misalignment, harmonics, wheels jamming on housing, engine backfire, surging.. there are plenty of things that can bend turbo shafts. I'd hazard a guess and say a combination of wear and heat cycling.

[Flannelman]

Seen the same on a BA Falcon XR6T. That instance the car was given some spirited driving then immediately switched off when they got back. Shaft temperature reached the point where the steal could be bent with the weight of the turbine.

While the circumstances are different, the outcome has been the same.

[Phothog]

The rear bearing cage has melted, the bearings that are suppose to be held apart are now touching each other, the inner race has been worn on one side of it.

Hence the reason it looks like its bent...

Which it could also be head droup, but with the sound it was making, most likely the above.

Seen this enough with the XR6-T Turbos...

Chris.

[matt dunn]

melted cage sounds right from what i have been told,

also have been told the the bearings from the ball bearing turbo will now be in the sump of the engine,
so the sump has to come off.

[Mr Ree]

Yes, I would definitely be changing the filter and flushing the engines oil system many times over with cheap dino oil, just to be sure.

Who knows how many tiny fragments of metal could be making their way through the system.

Goodluck, fingers crossed no other damage has been done.