on a 93 CTD or any for that matter, is there a maxium bearing play on the turbo impeller bearings. Say if one was to put a dial indicator on the impeller nut and check side to side play, what is acceptable????

Thank You.
Apache.

 

Go to Holset and download the service manual for your turbo. It will have all the specs you need.

Jay

 

After you build as many as we build, you sorta get the "feel" for it, and can tell what acceptable and what should be rebuilt.

When we upgrade a turbo, or fit a new compressor/turbine wheel into a housing, we make sure there is atleast a .025" gap between the side of the blade and the housing on each side. This is the minimum and maximum allowed clearance for the wheel. Any more of a gap and you lose airflow, and less of a gap and normal shaftplay could result in the wheel rubbing the housing.

When checking for shaftplay, take both compressor and turbine wheels in your hands, and move the shaft up and down, one at a time. The bearings are no pressed on the shaft, or into the housing, and they ride on oil, so there will ALWAYS be shaftplay.

For example, I just eyeball-measured a brand nw T3/T4 Hybrid Garrett Turbochargers shaftplay, and I'm guessing it's got about a .005"-.008" movement. I don't have a dial-indicator here, but we do use them in the shop, so I could test another for shaft play using the dial indicator after the holidays.

There should be no thrust play at all (back & forth) since the thrust bearing controls how much thrust the shaft is allowed. Shaft play should only be the minimal amount to let a layer of oil pass bewteen the bearing & shaft / bearing & housing.

I hope that helps a bit...

 

Thanks a bunch for the info, my friend has a 89 with 190k and says he has 0 play. This got me thinking, during the last service I grabbed the impeller nut and kinda went side to side with it and I felt movement, I never put a dial indicator on it. I was afraid of what I might see. I have not tried both ends or checked thrust tollerances.
I dont have any problems with my 93, smoking or noise and I always let it cool before shut down, guess Im to parinoid with repairs and maint.
I tried to download the Holset info, but where I live our internet connect is a slow 26 kbps and the download would take 30+ minutes.
I should install a pyro ,but I have yet to, Its stock, but the pump was rebuilt which was supposed to add 15%HP. Could one reach EGTs that would cook parts pulling and working it to hard?? I love to smoke them gassers and Ferds pulling grades with the trailer or camper.
Thanks again.
Apache