Bye bye banks turbo?

[legendman]

Originally Posted by IamDave0887

We really couldn't find anything wrong with it.

Pics?





What did you order?

Which turbo do you have?

If you couldn't find anything wrong with your turbo maybe the problem is some where else?

[turbonator]

Originally Posted by IamDave0887

Turbo is in pieces thanks to help from Dondandd.

We really couldn't find anything wrong with it.

You can see where the bushings contacted the shaft as there is a slight polish to the shaft, but there's nothing obviously damaged.

What i plan on doing is ordered a new turbo and rebuilding my existing one for a spare.

I have a feeling the current turbo has seen some very high EGTs going by the rig it came off of as it was used to tow something big and over long distances.

The truck was a converted TBI 454, crew cab long bed 2wd with a TH400, a USGear under/overdrive, a 5th wheel in the bed, full entertainment system complete with TV, and a sleeper mated into the rear cab window that extended into the bed.

couldn't find anything wrong with the truck body wise. No rust, no rot, nothing. The engine had a fairly fresh coat of cat yellow from top to bottom so someone built it. Couldn't find any external damage to the engine, but never heard it run either.

i did not realize the banks turbo was so big that it took 2 guys to R&R it........ so you are going to buy a new banks turbo? if you are buying the banks, seems pretty steep price to pay, consider from what you say it could be worth more than the truck.... should take kenny up on his offer for the gm-4 and just buy the pieces and rebuild the banks... just my .02 cents...

[acesneights1]

it's yours if you want it. I will give you an old downpipe to hack up.

[turbonator]

Good man Kenny, it will give Dave a chance to do some turbo comparisons and post up his results....

[D.Camilleri]

Your money Dave, but I don't think you have found the problem. Every bad turbo I have ever seen has had a ton of play in the shaft to where the fins would hit the housing, the shaft would be scored and basicly junk, usually causing the seal to fail and letting oil go out the exhaust. All turbo's typically have some play in the shaft, and when oil pressure fills the bearings it takes up the play. Typically the only time the shaft should touch the bearings is at start up or if the engine is turned off too soon before the turbo spools down. If the turbo would have been oil starved, the shaft would be shot. Did you look carefully for an exhaust leak before you pulled the turbo? When the turbo was off and on the bench, would the wheel spin easy? By easy, it should be smooth with no rough spots. Adding a few drops of oil to the oil inlet should make it turn free also.

[acesneights1]

Originally Posted by turbonator

Good man Kenny, it will give Dave a chance to do some turbo comparisons and post up his results....

I think the GM4 will out perform the banks but I would love to see a test.

[IamDave0887]

Originally Posted by D.Camilleri

Your money Dave, but I don't think you have found the problem. Every bad turbo I have ever seen has had a ton of play in the shaft to where the fins would hit the housing, the shaft would be scored and basicly junk, usually causing the seal to fail and letting oil go out the exhaust. All turbo's typically have some play in the shaft, and when oil pressure fills the bearings it takes up the play. Typically the only time the shaft should touch the bearings is at start up or if the engine is turned off too soon before the turbo spools down. If the turbo would have been oil starved, the shaft would be shot. Did you look carefully for an exhaust leak before you pulled the turbo? When the turbo was off and on the bench, would the wheel spin easy? By easy, it should be smooth with no rough spots. Adding a few drops of oil to the oil inlet should make it turn free also.

No exhaust leaks found. This engine is really sooty, so spotting a leak would be easy. i found nothing pre-turbo that would cause this.

Spoke with the head tech guy at banks and he says it's turbo related, along with a few other mechanic friends that have put their eyes and ears into this problem to help figure it out.


The shaft would not spin easily. It would bind randomly when turning it.

Adding oil didn't seem to help. it would free up for a second but would always return to sticking for some reason. If you let it sit for a bit it would be really tough to turn, but not a dragging against the housing kind of difficult. It didn't make any noise of wheels hitting housings when sticking and turning difficult.

I ordered a T04B from Banks, with gaskets and 3 day rush shipping for a little over $1,000.

The GM-4 won't out-perform the banks turbo. The banks unit doesn't have that backpressure wall, and with no overdrive, that's exactly where the engine sits on the highway. The banks unit is much free-er flowing. Sure the GM-4 would boost better off the line, but it would choke up later on.

The GM-4 wouldn't fit either. The GM-4s exhaust elbow is cast iron. There is no cutting and re-welding that to be leak free. The elbow points down at a 90* angle, where as the banks turbo exits right out the back of the turbine housing.

It is what it is.

I'm planning on ordering a CKO HX40WII and the downpipe kit for the other truck too as i have a bit of extra money coming in from a stock market fund of mine.

Eventually i will order a rebuild kit for the current turbo and keep it as a spare. I only paid $300 for the entire Banks kit including 3/4 of the exhaust system. The turbo doesn't owe me anything. I got 20,000+ miles out of it, and i ran it hard too.

[D.Camilleri]

Dave,

It would be interesting to put a dial indicator on the shaft of your bad turbo. Remove the compressor wheel and indicate the shaft. I am thinking it sounds like the shaft could be bent and causing a bind up in the bearings. In fact, if found to be bent, it could have a crack and be ready to break. Just a thought. I would expect to see some runout based on your symptoms.

One other thought, could be a problem with the seal in the turbo, binding up.

[tanman_2006]

I have a rebuilt banks t04b on the shelf. If i would have seen this thread earlier i would have made you a deal... Its set up for running on 6.5's with a custom DP elbow.

Glad you got it figured out.

My GM3's cast turn down unbolts from the turbo fyi. I think a new flange could be made with a direct outlet.

[IamDave0887]

Originally Posted by tanman_2006

I have a rebuilt banks t04b on the shelf. If i would have seen this thread earlier i would have made you a deal... Its set up for running on 6.5's with a custom DP elbow.

Glad you got it figured out.

My GM3's cast turn down unbolts from the turbo fyi. I think a new flange could be made with a direct outlet.

Damn it....

Oh well. New turbo arrived yesterday.

Still want to sell it?

Another spare cant hurt, and i'd like to see how a banks until runs on a 6.5 anyways. lol.

Gonna order a HX40WII for the 96 at some point.