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mark houghton mark houghton is online now
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Join Date: Jul 2008
Location: Central Washington State
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Originally Posted by mark '87 930 View Post
Thanks Mark. I didn't mention the rebuild of the turbo much as it seems to be 'taboo' to rebuild your own turbo. I bought a rebuild kit and have most of it apart already (I've done it before on a different turbo) but I'm having a hard time with the turbine housing and getting it off. Will tackle that tomorrow.

I'll have to check the housing to make sure it's still ok. There was enough shaft play that I could feel it without it being on a dial indicator, so I knew it had to be done. Only had 10-15K miles on it though since new.
Two types of play to look for....radial and run-out. Run-out should be almost non-existant (I don't know the specs), and excess would indicate the thrust plate is worn. Radial, when applying sideways pressure to either end of the shaft, definitely should not cause contact of the wheel with the housing. Apply pressure and slide a feeler gauge between the wheel and the housing. Anything less than .005 inches clearance would indicate new bearings at the least, because the balance would be compromised and risk rubbing on the housing. I am by far not an expert and as with everything I start by learning from others and then by doing. Get everything apart and look for signs of wear. Stock sizing and dimensions are available to compare your wear against.

I think we've all been led to believe that turbo rebuilding is a taboo subject for the DIY'er. That's true if rebalancing is needed. Otherwise, these things are pretty straighforward. Even brand new, there will be a lot more "play" than a person would think, given that the bearings are sized to allow the shaft to ride freely in a layer of oil by design.

I could be all wet - and I'm sure I'll hear about it from my esteemed friends out there, but suffice it to say that other's have successfully done this. I like pushing the envelop and challenging conventional wisdom...that's my nature.
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Mark H. 1987 930, GP White, Wevo shifter, Borla exhaust, stock everything else. The result of a massive Pelicanite good will fire recovery effort. Truely an open book, ready for the slippery slopes to modification.
Old 01-08-2010, 05:57 PM
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