How to rebuild a turbo

[chomerly]

Ok,

This is my first guide on this site and i hope i am able to give you most of the answers you need to do the job ahead.

My battery ran out on my phone near the end of this guide but there should easily be enough for you to complete the later part of the rebuild.

Things you will need.

A good set of sockets, extension bars and spanners.(mostly 10mm, 12mm, 13mm and 17mm)
A Torque wrench.
A good set of screwdrivers. (Flat head and posi)
A set of allen, or hex, keys.
A set of torx bits.
A bench vice. (ideally but can be done without)
A tube or bottle of assembly lube.
A tube of thread lock.
A lot of rags and/or blue roll.
A can of carb cleaner and a can of WD40.
About 1 litre of your preferred engine oil
your rebuild kit.
A box of non-powdered gloves or swarfega.
And last, but not least, a swear box because the cussin' you are going to do is going to make Chubby Brown sound tame.

First thing we need to do is jack the front of the car up and support it with axle stands.
We then need to get as much stuff out of the way as possible so remove the engine cover, the exhaust shield, the battery, the air box, the Turbo control valve (TCV) including hoses (make note of their individual locations), the hose that goes from the air box to the turbo and the top hose from the turbo.

Before you do any of this, if you have any plans on doing a service on the car then draining the oil and the coolant would be a good idea to do now while you get on with all of the above.

Next thing to do is to remove the the bottom hose from the inter-cooler so that the plastic pipe that goes from just above it, into the engine bay and at the side of the engine can be removed.
Please take care with the bottom hose because if your turbo has been blowing oil it will gather here.

By this point you should have gone from this



To This.



From here on in it is pretty self-explanitory on how to remove the turbo.
Undo the water lines on the rear using a short 17mm socket and the oil feed at the top.
The oil return is a pain in the rear to undo in situ so just leave that attached for now.
That leaves 7 bolts on the exhaust side to undo as pictured here.



There will be one that will do your head in as it is in a very awkward position.
It is the one that is partially undone at the bottom left.




Once you have those bolts undone i would then consider removing the water hoses for the cabin heater.
It should only be as simple as removing the jubilee clips and, if you want to, flush the water out of the matrix by fitting a hose pipe on one of the pipes for a couple of minutes and then on the other for the same amount of time.
It may come out looking a little off colour at first.
This will be because of the coolant and contaminants being flushed out but don't worry, it's a good thing.

Now to remove the turbo.

You may need a soft hammer in order to get it off because if it's anything like mine and it's been on for quite some time then you will definitely need a persuasion device of some kind.
I would also refrain from hitting the turbo directly as you may cause some damage to it.
I got mine off by hitting the ends of the bolts that are protruding out towards the left hand side of the turbo/exhaust.

Put the nuts on the bolts so that only a small portion of the bolt is exposed and then hit them in turn until it is eventually moving freely.
from here on in it's a case of twisting and turning the turbo until it is totally free from the car.


Now for the turbo rebuild.


This is where your Carb cleaner, or WD40, and a plentiful supply of rags and/or blue roll comes in handy.
Especially if your turbo has been blowing oil.

Firstly, remove the turbo actuator and then the blow of valve from the housing.



I would place the actuator onto something so that the nozzle is facing directly down towards the table.
If your turbo has been blowing oil it will accumulate in there because the TCV has been pumping it through as a result.
Place some rags under the nozzle to capture the oil that will initially pour out of it.
As a matter of course, it would probably best to replace it all together.
Also, the blow off valve will be quite wet with oil for the same reasons.
Just remove the blow valve and then remove the diaphragm and give it all a good clean.

Next thing to do is to remove the retaining clip ring that holds the centre cartridge to the combustion housing.
Again, if it has been on there for some time then you will need your soft hammer again in order to get it off.
When you have you should end up with it looking like this.



At this point for me i knew my turbo was screwed because of the vast amount of damage on the turbine wheel.
And it was clear that the damage wasn't new but maybe my Italian tune up exacerbated an already degrading turbo.
It's so bad that i feel this image was in order.



I couldn't leave the turbo as it was as i feared that the thing would eventually explode into bits and the last thing i wanted to do was buy a complete unit, including compressor and combustion housing so i did the repair on it anyway.

The next thing to do is to get the compressor housing off.
To do this you will need to remove the mighty circlip and this will require some hand strength and a damn good pair of long nose pliers.



Once it is off then pull the compressor housing away from the cartridge.
you should now be at this stage.



Give the compressor housing a damn good clean and get rid of as much oil as is possible.
It doesn't have to be showroom clean but the less filth there is to contaminate the finished turbo the better in my view.

Now for the meat of the turbo.

The bearings in my turbo were shot.
I decided that a video was in order to show exactly how much play there actually was.

http://youtu.be/jaGFBSJVLJs

Before you disassemble the cartridge there is something important that needs to be done.

Before removing the nut for the compressor wheel, you should mark the exposed shaft and the compressor wheel so that both marks line up.
I didn't know this until i was looking around for turbo re-furbisher's but turbo's are balanced from the factory so by doing this you will maintain that balance by re-aligning those marks when you reassemble the cartridge.
Something like this will suffice and i apologise if you can't see it clearly.



To disassemble the cartridge you will need to firstly undo the nut at the compression wheel.



Next you will want to remove the turbine wheel/shaft.
this should be as easy as tapping the end of the shaft on your table top but with the nut on it so you don't knacker the threads.
There will also be a back plate that will come off with it also.

Once removed you should have something like this.



Next, you will want your long nose pliers again and you want to remove the circlip keeping the oil sheild in place.
Once the circlip has been removed you will need to remove the oil sheild.
This won't be easy to do so i took a flat head screwdriver and prised the thing up until it eventually came off.
Under the sheild there is a deflector plate that needs to come off.
I simply pulled on mine as the oil seal around the thrust collar was brittle and broke in two with the slightest of pulls.
once removed you should see this brass coloured thrust plate.



This is fairly easy to remove using a flat head screwdriver.

Once removed turn the cartridge upside down and the old journal bearing should drop out.
Lastly, remove the O-ring using the flat head screwdriver and that is your turbo cartridge disassembled.

This is your opportunity to thoroughly clean as much of the housings and cartridge as possible but be careful to not leave any foreign debris in anything that you clean.

The reassembly is basically the reverse of the disassembly but with the new rebuild parts.
Crack open the rebuild kit and compare the parts you need to the parts you have removed.
Starting with the turbine wheel apply the new oil seal as pictured here.



Once you have done that you then need one of the new journal bearings.
Apply a generous amount of assembly lube



and simply slip over the turbine wheel shaft.



Next you take the back plate and put it into place



followed by the turbine wheel.

When you push the turbine wheel you will hear a click as the oil seal locks into place.

Next take the other journal bearing and lube it up (ahem) and slip it over the shaft and push it down as far as it will go.
You then need to take the smallest of the two thrust bearings and put that over the shaft with the base sitting on the journal bearing you have fitted.
It should be like this.



Next, take the new thrust plate and fit it according to this picture.



Once you have done that you can then fit the smaller of the two O-rings.



Next, take your oil shield deflector plate and place the larger of the two thrust bearings in it's centre.
You can then place the oil seal around the thrust bearing and then fit the deflector into the oil shield like so.



Next, fit the shield over the shaft and slide it down so that the deflector slips into the gap left by the thrust plate.
This can be a real bastard to get it into place as the new O-ring will grip it.
I used some hand clamps to do this but it can be done using a bench vice.

Get a long socket that will fit over the shaft and on to the oil shield.
place the unit onto the hand clamp or vice and keep squeezing it until it has pushed the sheild down enough so that the gap that the smaller circlip sits in is visible.
Once done you should be at this stage.



Fit the circlip



Then fit the compression wheel.
Take note that the two marks should line up or be pretty close.

Next, take your thread lock and place a small amount on the shaft just above the compression wheel and then take your new nut and screw it on.
Take your torque wrench and fit it to the turbine side nut. This has a 12mm head.
Next, use an 8mm spanner on the compressor wheel nut. All you need to do with this nut is hold it with the spanner. The tightening will be done on the 12mm head side.

I set the torque to about 9 ft. lbs which should be more than enough.

Next, take the larger of the two new O-rings and fit that in place.



Once you have done that you can then get on with refitting the compressor housing.
If you look at the compressor housing, you will see a pin.
You need to line that up so that it fits in this hole.



Once it's in place you can then fit that BASTARD of a circlip in place.
Next fit the turbine housing and again, there is another locating pin, and then you can refit the ring clamp and tighten it up.

Refit the blow off valve and then the actuator.
Next refit the oil return pipe using the new gasket and make sure you refit the O-ring seal.
For good measure, add a little instant gasket above the O-ring for extra sealing.

And there we have it. One rebuilt turbo.

All there is to do from there is to refit the turbo and away you go.

Unfortunately for me my turbo was beyond help so all i can do is buy a new or replacement cartridge but hopefully, for anyone attempting to rebuild theirs, it will do the job just fine.

Let me know your comments guys.

[T4Rick]

Nice guide mate

[m1tch1987]

What rebalancing machine are you going to use for the assembly? The compressor wheel will be slightly worn meaning it won't be balanced the same as when it came from the factory.

[Clan]

yes it is crucial the rotating parts are balanced as there are huge forces acting at 200,000 rpm with even the tiniest out of balance force . .

[chomerly]

It is true that you do need to re-balance your turbo if it was being repaired from the state mine is in. But if your own turbo compressor and turbine wheels are undamaged, and its a case of replacing the bearings, then all you need to do is mark the top of the shaft and mark the compressor wheel and there will be no need for re-balancing.

I'll be buying a replacement cartridge for mine.
It's comparible in price to buying a separate turbine and compressor wheel and having your turbo balanced afterwards.

[T4Rick]

Originally Posted by chomerly

It is true that you do need to re-balance your turbo if it was being repaired from the state mine is in. But if your own turbo compressor and turbine wheels are undamaged, and its a case of replacing the bearings, then all you need to do is mark the top of the shaft and mark the compressor wheel and there will be no need for re-balancing.

I'll be buying a replacement cartridge for mine.
It's compatible in price to buying a separate turbine and compressor wheel and having your turbo balanced afterwards.

Ive rebuilt a few garret t3 turbos and a 15g for my T5 and it was all good.Its a job you carnt rush and checking measurements and clearances is a must,its a job for a competent person and also confident

[chomerly]

Originally Posted by T4Rick

Ive rebuilt a few garret t3 turbos and a 15g for my T5 and it was all good.Its a job you carnt rush and checking measurements and clearances is a must,its a job for a competent person and also confident

Most definitely Rick.

It's amazing how simple these things are but if you're not confident or competent then it's best to leave it to the pro's or someone you know who can do it.

[chomerly]

I would also like to add that if anyone has a turbo for sale (just the cartridge really) and both the compressor and combustion wheels are intact then let me know.

I also don't mind if it has a little play in the bearings as I can strip mine and use those.

I miss having that oomph that gives me a thrill each time I put my foot down.

[Clan]

Originally Posted by chomerly

It is true that you do need to re-balance your turbo if it was being repaired from the state mine is in. But if your own turbo compressor and turbine wheels are undamaged, and its a case of replacing the bearings, then all you need to do is mark the top of the shaft and mark the compressor wheel and there will be no need for re-balancing.

I'll be buying a replacement cartridge for mine.
It's comparible in price to buying a separate turbine and compressor wheel and having your turbo balanced afterwards.

how much is an overhaul kit these days ? You mention marking , that is another critical area , any scratch or indentation on these highly stressed turbine wheels can cause disintegration at high rpm , a felt pen should be ok though !

[T4Rick]

Originally Posted by Clan

how much is an overhaul kit these days ? You mention marking , that is another critical area , any scratch or indentation on these highly stressed turbine wheels can cause disintegration at high rpm , a felt pen should be ok though !

a permanent one.The last one i used started to rub off lol