parish8

iTrader: (6)

i have had the opertunity to work with 6 diferent turbos now. brand new they all had noticable play in the shaft. more than i thought should be normal but they were all brand name expensive turbos and worked fine. i would say a prety easy .010 from pushing it one direction to pushing it the other direction.

sounds like a u joint to me.

kbracing96

iTrader: (26)

You guys seem to think .020 is too much so i googled it and came up with any where from .018-.022 for a side to side spec with most every site I found.

http://wwwrsphysse.anu.edu.au/~amh110/turbo_page.htm

kbracing96

iTrader: (26)

FWIW they have this much clearance because they use whats called a floating sleeve type of bushing where the shaft spins in the bushing and the bushing spins in the house, dividing the the turbine speed between the two.

I, like the others think your noise is coming from something else. It may have already been there, you just won't lessening for it before

Steve88

iTrader: (5)

I would agree that the noise is probably from something else besdies the turbo. I have been racing turbo Buicks since the early 90's and I have seen some pretty worn and tired turbos with quite a bit of slop that still wouldn't rub the housing. The first time or two I checked a turbo for play I was shocked out much there was but now I don't sweat it unless the turbo is using oil. In my experience using oil is the first sign of trouble so if its not using any its probably OK.

TG02Z71

iTrader: (2)

Great information, I would never have thought you could get away with so much play on something spinning 80,000rpm or more!
I guess when all the internals are warmed up that could cut the cold tolerances in half leaving just the right amount for lubrication.

Steve88

iTrader: (5)

Most of the clearance goes away when oil pressure is added. I have a friend with a preluber pump that builds oil pressure without the engine running. You can wiggle the shaft in the turbo and feel it move then when he turns on the 40 psi pump there is no more movement instantly.

GOGO-C

I put 55k on my 67 and no probs ever . these turbos are designed to out last your truck . sounds like mabe a loose exahust hanger.