How to Rebuild the Turbo
By Everet
I just got off the phone with Turbo City. They do in fact have a video for the seal
replacement procedure and the seal and gasket kit is $150.00 per turbo. I was lead to
believe it was $150 for both. Any confirmations from anyone before I order?
Well I did the rebuild on my turbos today and thought I’d pass along my experience
for those who may be considering doing it themselves but not sure what kind of job it is.
First of all it’s really quite simple and there’s not a whole lot too it. In
fact, I was surprised on how "non-precision" it was overall. I expected much
closer tolerance components with a bit higher complexity than a couple bronze bearings and
a couple simple seals.
I bought my kits from Turbo City. You need two kits ($150.00 each) and they have a
video as well that is worth the $16.95 when purchased with the rebuild kits. It’s
generic and our assembly is slightly different, but it’s good to give you a good
understanding of what you’re going to encounter before you start disassembly. The
seal plate and the bearing housing need to be thunked apart with a hammer and that may not
be obvious if you hadn’t reviewed the video.
Tools you’ll need
10mm wrench
4mm Allen wrench
pointed probe/dental pick
snap ring pliers with .030 tips
large snap ring pliers
small screwdriver
soft face hammer
marking pen
glass bead blaster
carb cleaner
wash tank
compressed air
Rebuilding the Turbo
Expect it to take the better part of a day unless you’ve done it before. It's
probably only a couple hour job if you’ve got everything together and know what
you’re doing. Getting the snap rings in and out took me as much time as anything, but
most of your time will be spent cleaning parts. I would recommend if you don’t have
access to a glass bead machine that you don’t do this yourself. I did the whole job
at Precision Systems Inc. (the machine shop I manage). You need lots of compressed air
too.
Glass beading all the parts and then getting them clean and free from the glass bead
can take a while. Get yourself a couple cans of Gumout Carb Cleaner to get the glass beads
out of your parts. This can be the death of the turbos if there is any residue left
behind. That’s the only cleaner I’ve found that will get the beads out for sure.
If you don’t have the right snap ring tips get them first or you’ll spend all
day trying to get them in and out. Don’t let the video fool you when the guy seems to
effortlessly snap them in and out with a probe and his finger. If he can do that on these
turbos he’s my hero!
You’ll notice the carbon seal is a complete assembly that needs to be pressed in
and out instead of separate pieces like shown in the video too. The seal is a little
different than the one you’ll be taking out.
Remember to mark your parts for alignment before you disassemble and keep things CLEAN.
Once you’ve taken one apart it goes together in about 10 minutes.
The total cost was $320.00. In my opinion anyone with access to a shop and a little
mechanical knowledge can do this. It’s a piece of cake. Put all those hundred dollar
bills into something else rather than pay someone else to do it. It’s a hell of a lot
harder getting the turbo out of the car than rebuilding it. All the other procedures
people have mentioned to me that the turbo rebuilders do don’t add up to a hill of
beans IMHO. If you do it yourself at least you know it’s done right! (?)
Now that it’s done it spins like a top and looks like a million bucks! Maybe
I’ll just put it on my mantle and spare myself all the headaches of getting it back
onto the engine! :-)
<<I also got the rebuild tape, and reviewed it a few days ago. It does look
pretty simple, but I’m curious about how your turbo’s looked *before* you
took ‘em apart. Were there symptoms, and how did the old parts look? Did you see any
obvious signs of failure in the seals?>>
There was a lot of gunk and black crap all over one of the turbo and compressor
housings. It appeared to me that the leaking was coming from the large o-ring and the
turbine seal. The turbine shaft seal was very gunked up with carbon and scale. I was
concerned with the big snap ring that holds it all together too. That’s all that
keeps the o ring compressed properly and it’s hard to tell if it is seated well. I
put two small clamps against the compressor housing and the bearing housing squeezing them
together while I pushed the large snap ring in a bit further just to be sure.
<<Did the rebuild kit include instructions for compressor wheel nut
torque?>> No
<< What about cautions to help prevent damage to the shaft or bearing surfaces?
Did you do you do the shaft polishing with fine paper? In a drill press or a
lathe?>>
I cleaned the shaft with some very fine scotch-brite and then a very hard white stone.
It really didn’t require much. I did them in a drill chuck on a mill. The cleaning
was in the area that holds the turbine shaft seal. I carefully glass beaded that with 40
psi along with the fins staying away from the shaft itself.
<<Any thoughts on getting the rotating assembly balanced, or doing any
grinding/polishing in the turbine housing to prevent hot spots and cracking?>>
There’s no need to rebalance the assembly. It was balanced when built and as long
as you mark the compressor wheel and the turbine wheel before you reassemble it will still
be just as balanced as it was originally. There was a tiny number 6 on one of the wheels.
I just used marking pen to mark the opposing wheel lined up with the 6. You don’t
want to make scribe marks on the wheels.
<<Did you see any signs of cracking? Any signs of heat damage to the compressor
wheel? >>
My wheels had no sign of any damage or hot spots. A very low pressure glass bead took
the gunk off the one that was leaking and the others looked like they were brand new.
<<Did you use straight oil for the bearing/shaft reassembly?>>
Just smeared a little motor oil on them. You just don’t want them spinning up the
first time dry.
<<I think it’s also recommended that the oil feed lines get replaced, not
cleaned, as I’ve read that it’s very hard to get them perfectly clean. Nothing
sucks more than running some dirt into your nice clean turbo...>>
That’s probably reasonable advice. I personally sprayed quite a bit of carb
cleaner through the oil line while I rotated it around and blew it out and repeated that a
couple of times. I see no need to replace it. You stand more chance getting something in
you oil every time you do an oil change if you ask me.
<<It would probably be a good idea to make sure the turbo’s are fully oiled
before first running the engine by doing some cranking with the fuel pump fuse
removed.>>
I agree.
<<Lots O’ questions, ;-) let me know if you’d like me to put this in a
1, 2, 3,... format so they’ll be easier to answer, and send a copy of the response to
the list. Thanks, David >>
I will add that the 4mm Allen wrench was really a 2.5mm and you need a torx wrench as
well to get the stock screws out of the thrust bearing.
Also, I didn’t glass bead the cast iron turbine housing. I cleaned the outside of
that with a wire wheel and then soaked it in a solvent tank and then cleaned it with carb
cleaner. I felt it would be too much of a chance to take not getting the glass out of the
little oil holes in that. You also want to be sure you use some scotch-brite or fine paper
to clean the buildup out of the seat where the turbine shaft seal mates.
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