turbo ???

[EscaladeDiesel]

I have the GM-8 turbo out and off of my '98 Suburban. I do not know much about them, is there a way I can tell if it is OK without taking it apart? The impellor spins, but with some resistance and I am not sure if that is as it should be or not.

[ 07-02-2004, 09:50 AM: Message edited by: EscaladeDiesel ]

[turboGMC]

Its hard to tell how much resistance your talking about if it spins freely. It should have very little.

The initial way to see if a turbo needs rebuilding is to see how much play the shaft on the impeller wheel has. Up and down-there should be a little. Id say 1/8 inch or less. Even new it has a little play so dont get too worried. ~~And then in and out- it should have almost basically none. Very little and you it will be kinda hard to tell it is even moving. Ive got 140xxx on mine and it is still in that condition.

[EscaladeDiesel]

can this be checked as is, or must the inlet cover be taken off?

[grape]

just reach in and grab the nut that holds the inlet wheel on..........WHITHOUT THE TRUCK RUNNING.

[EscaladeDiesel]

its off the engine (which is out of the truck)..the shats has ZERO movement in any direction, thought it was supposed to have some movement, especially since this is not a new turbo.

[Salemone]

Sounds like you have galled bearings and shaft.
The impeller should turn freely. The shaft also could be "coked up". Just needs cleaning.

[EscaladeDiesel]

not knowing how the impeller is supposed to spin, all I can say is that is spins when you twist it, but it does not continue to spin when you stop, is it supposed to spin more freely than that? Also, what is the best way to clean it what do I take apart? What products? thx

[ 07-04-2004, 08:05 AM: Message edited by: EscaladeDiesel ]

[ees]

In my experience with gas turbos the turbo does not continue to spin after you flick it. Shaft play should be on the order of tens of thousandths of an inch. I imagine it is slightly different from turbo to turbo. It is hard to feel. You really need a dial indicator to see it.

If it spins smooth (no rough spots) and all the fins look good you likely have a turbo that at least has some more miles in it.

-Eric

[gmctd]

Put it on the truck and run it a bit.
Check it when warmed up, with fresh hot oil in the bearings, engine off - should spin more freely, with little side play or end play.
But, it will spin freer and somewhat longer.

[ 07-06-2004, 06:21 PM: Message edited by: gmctd ]

[EscaladeDiesel]

cant put it on just yet (see my other recent post). I am scatching my head, as everyone talks about "play" and the shaft on my turbo has zero, its completely solid, no play in any direction, and this is a turbo that has almost 50,000 stop and go city miles on it.

[jcomp]

If I read your other post correctly, your old engine failed due to lack of oil. It's possible your turbo was also oil starved and was damaged. I would suggest that you have it looked at by a professional. Not your mechanic, but someone who specializes in turbos.

Your turbo may or may not have lots of miles left in it. Personally, I would have it looked at just for the peace of mind.

[EscaladeDiesel]

Took my turbo to Majestic Turbo in Irving(Dallas) he said it was as tight and w/o play as one can be and that it should be just fine.