GT-67 questions
#1
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GT-67 questions
Hey guys, I have been hearing a weird tink tink tink noise from the truck under little throttle so I investigated today. I took both the filter and exhaust off the turbo, then I stated checking for slop in the turbo because I think the sound is like the turbine hitting the housing. I can move the shaft up and down and side to side a little bit. What are the tolerances or are there any? I feel there should be absolutely no slop what so ever, but am I wrong? I can feel the slop if I hold on to the intake side and move the exhaust side. It has done this since I put the damn thing on, that is why I havent gone wot. I have only made it to 60 percent throttle for less than a second because of it. Ahhhhhhhhhhhhhh, I dont think I'll ever get this thing running.
#3
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There should be a bit of side to side movement because of the way the bushings work, I believe .020 is with in spec (about the thickness of a match book cover). If the trubine is hitting the housing, it usually makes a loud whining noise that will change pitch with the speed of the turbo.
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there should be play from side to side. i don't know about .02, but there should be some. best thing to do is sort of push to one side and spin at the same time. if you can get it to scrape the housing while spinning with your hand, you definatly need a rebuild.
other thing you need to look at is oil consumption. if your all of a sudden burning oil, chances are your turbos going. if your bearings start the loosen up, they will also screw with the seals making it blow oil.
the tolerance you should really be worried about is the thrust. the back and forth. there should be hardly any. if there is a lot of play there, you need a rebuild.
thing about rebuilding is that you should do it even if its a small problem. when turbos go, they go fast and the longer you wait, the more expensive it gets.
a regular rebuild kit for a standar t3/t4 or t4 will run you about $40 for the bearings. if you need the oil race and/or thrust bearing too, your looking at $100. a small price to pay for a $900 turbo.
this is the reason ball bearing sucks *****. if you have a bearing problem on one of those, good luck buying a new cartridge. about 70% of the cost of a brand new turbo.
if your mechanically inclined you can definatly re-build it yourself. just make sure to remeber that the nut on the compressor is a left hand thred.
you could also be hearing a u-joint slowly going as well. double check and make sure its not some suspension or drive train noise before you start tearing things apart.
other thing you need to look at is oil consumption. if your all of a sudden burning oil, chances are your turbos going. if your bearings start the loosen up, they will also screw with the seals making it blow oil.
the tolerance you should really be worried about is the thrust. the back and forth. there should be hardly any. if there is a lot of play there, you need a rebuild.
thing about rebuilding is that you should do it even if its a small problem. when turbos go, they go fast and the longer you wait, the more expensive it gets.
a regular rebuild kit for a standar t3/t4 or t4 will run you about $40 for the bearings. if you need the oil race and/or thrust bearing too, your looking at $100. a small price to pay for a $900 turbo.
this is the reason ball bearing sucks *****. if you have a bearing problem on one of those, good luck buying a new cartridge. about 70% of the cost of a brand new turbo.
if your mechanically inclined you can definatly re-build it yourself. just make sure to remeber that the nut on the compressor is a left hand thred.
you could also be hearing a u-joint slowly going as well. double check and make sure its not some suspension or drive train noise before you start tearing things apart.
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#10
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i think i remember garrett bb turbos had a shaft play of about .004~.007. being ball bearing, i can see them having a little tighter clearences, however i wouldn't think a journal bearing would have over .01.
.01 on any bearing clearence is a ton.
also, your going to hear a wierd shattering sort of sound at lower rpms if the wheels are touching. once you give it a little gas it will go away.
i just had to rebuild my t3/t67 a couple months ago. my thrust was so far out it ate the backplate as well.
.01 on any bearing clearence is a ton.
also, your going to hear a wierd shattering sort of sound at lower rpms if the wheels are touching. once you give it a little gas it will go away.
i just had to rebuild my t3/t67 a couple months ago. my thrust was so far out it ate the backplate as well.