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DIY Turbo Discussion greddy on a 1.8? homebrew kit?

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Old 01-02-2011, 01:10 PM   #1
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Default question for anyone that has ever rebuilt any turbo

bought an oem SR20DET garrett T25 turbo. There was a little shaft play so I rebuilt the turbo with an ebay kit.

Thing is, although the shaft seems to spin freely and smoothly, it takes more effort than the new chinacharger t25/t28 I also have as a backup. It just takes a little bit more effort to start/keep the fan assembly by hand than it does the chinacharger, which starts to spin if you just look at it.

Everything looked ok during the rebuild, apart from the journal bearings, which were for the longer version of the T25 bearings, so I had to reuse the old journal bearings. Only other difference was that the C clips were a standard type, versus the "wavy" type that came out of the turbo originally. Also, I only pulled out 2 c clips for the journal bearings from the stock turbo, even though the gpopshop diagram shows that there should be 3 clips. The rebuild kit had 3 clips, and I used all three. I did use oil when installing and dumped a bit into the CHRA

So the question is, has anyone rebuilt a turbo and found the effort needed to spin the shaft increased slightly? Will the shaft kind of "break in" and spin easier after it's been installed and run for a bit? Wondering if I should maybe rebuild again with a Gpopshop kit instead of an ebay kit, although I suspenct they are the same parts.
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Old 01-02-2011, 01:51 PM   #2
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The two sr20's I had both did not move very freely compared to new turbos, but I'm pretty sure that's totally normal. They should also loosen up once they are properly lubricated.
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Old 01-02-2011, 02:11 PM   #3
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mine seemed to be fine. I used the GPopshop rebuild kit and was just extremely ---- about cleaning everything in the parts washer , lubricating everything, and keeping it all in the right order.

Did you also mark your orientation of the wheels so that they are still at least close to balanced?
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Old 01-02-2011, 02:41 PM   #4
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Sounds like I might be ok. heartening.

Yeah, I scribed the front nut. Reused it since there was no way to scribe the replacement nut and have it match. It's a nut, doesn't really go bad.
The turbine wheel/shaft was a solid assembly, it had a hex end with about 50% of it grinded away, presumably for balancing purposes. Made grabbing it to remove the compressor nut hard, had to use locking pliers and pray they didn't slip.
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Old 01-02-2011, 04:23 PM   #5
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The journal bearings need oil in them for it to spin freely. When I rebuilt my 15g it didnt spin as well as I thought it would too. I took it out a little while ago after running it in the car and with oil in the bearings it spins pretty freely.
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Old 01-02-2011, 04:31 PM   #6
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I rebuilt a Garrett CHRA last spring and it was a bit tighter than I expected, but still spun freely. It worked great once I got it on the car.
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Old 01-02-2011, 04:34 PM   #7
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What about carbon? I rebuilt mine a while back that I purchased on here, and it didnt spin to freely until I had to scrape mass amounts of carbon from here:

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Old 01-02-2011, 04:38 PM   #8
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yeah, I have a wire wheel on a drill press and I cleaned the **** out of everything that was being reused.

this seems more common than I knew - I'll go ahead and install it. Any problems should be apparent pretty quickly, even if it's with a smokey death.
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Old 01-02-2011, 04:41 PM   #9
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Quote:
Originally Posted by tronik View Post
yeah, I have a wire wheel on a drill press and I cleaned the **** out of everything that was being reused.

this seems more common than I knew - I'll go ahead and install it. Any problems should be apparent pretty quickly, even if it's with a smokey death.
good luck to you then!

I just sure as hope you didnt hardcore wire wheel the shaft itself. I trust you didnt.
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Old 01-02-2011, 04:48 PM   #10
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I did the part around the turbine, where the collar and grooves are. In some diagrams, there is a second seal or clip that is meant to go in the forward of the two grooves. Mine didn't have anything in it, and there was oil sludge baked into the groove. More sludge on the back of the turbine wheel. I did see from google searches that others didn't have a second seal/clip in that groove.

I did wire off the sludge, but the wire wheels I use can't take off any metal. I've used them extensively during the rebuild of this car to clean parts, bolts etc, and it's been super useful. Never seen it impact metal though, apart from soft aluminum, which it shines up.
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Old 01-02-2011, 04:55 PM   #11
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Good deal, I just wished I had a wire wheel setup like you have... I am stuck with primitive tools like SS, copper, and steel wire hand brushes. Is the seal on the exhaust side of the shaft able to move around?

EDIT: I ask this because when I was rebuilding the same turbo, I had a new piston ring, but the ring was a little to big that when it was compressed, it didnt seat in the grove totally, thus not allowing the whole shaft to fit in the CHRA until I dremeled 1mm off one end. After that, with a little tap with my palm, it popped in with the ring fully compressed and seated.

#5 is what im referring to.
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Old 01-02-2011, 06:08 PM   #12
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yeah, same thing with mine - in snapping it on, as well as the one that goes on the thrust bearing, it bends the ring outwards. No amount of squeezing it in pliers could get it to sit in the confines of the groove - but I think that's actually the point. It prevents the assembly from sliding out of the CHRA. I had to tap my turbine wheel shaft into the CHRA with a hammer, until it snapped in.

Unless something catastrophic has happened with the turbo, I'm pretty sure that it's the thrust bearing that's responsible for most of the shaft play turbos get. Everything else is just "while you're in there".
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Old 01-03-2011, 01:39 AM   #13
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Quote:
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nice
GET THE **** OUT.


you and YOUR bullshit post, we are not going to buy **** from you!!!
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Old 01-03-2011, 03:56 PM   #14
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I bought a reconditioned exchange turbo from turbo technics highly regarded here in the UK. I remembered that it was tight...yes it would turn by hand but needed a little effort was tight there was absolutely no play back and forth nor side to side. when fitted was very fast car so no problem there. I wouldn't be concerned sounds like mines.
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