I have been fusing around with the Turbine housing on my S4 turbo for the past 2 hours and I cannot seem to get it off. I have used wd40 and tried pulling it but it does not give.

If I am not mistaken two or three bolts will stay on until the housing comes off the center section right? So whats the trick to removing it from the center section?

 

Umm... I think theres only one bolt you need to rotate the housoing to get at?

Either way, the secret is to use a metal tipped hammer to hit it.. just enough to move it. Then you can rotate it to get the last bolt(s) off quite easily.

 

I have all the bolts loosened all the way till they hit the center section...what do you mean rotate?

 

Umm... loosen the bolts so they are loose, but NOT touching the center section, then grab a hammer and try tp hit either the center section or the turbine housing to try and rotate the turbine housing with respect to the center section.

The housing is just effectivly clamped to the center section of the turbo, the bolts don't go through them both. So you only need the bolts loose before you can rotate the housing and get all the bolts out.

Also make sure when you DO eventually get all the bolts out and your ready to finally take the housing totally off remember to make sure it comes off slowly evenly and STRAIGHT so you don't hit any turbine wheel fins.. that is bad..

I'm really sorry I dont know how to explain it any better than that. If you still don't understand maybe you shouldn't try attempting this yourself just yet.

 

They can be really tight. If none of the above work, heat it up with a gas welding torch. It'll expand and pop right off.

 

Your talking about those 13mm bolts right?
Two of the should be touching the center section on the oil supply flanges.

Just keep on "loosening" the bolts.
When you do that the bolts will push against the center section and pop it loose from the turbine housing.
Just make sure you loosen them alternatively with slight turns.
ie one turn on one and one turn on the other one so that your compressor/turbine wheel wont press against their respective housings

 

Err.. Also just making sure.. before you separate the assmbly, make sure you mark the center section and the compressor/turbine housings so that you will have no problems re-assembling them.

 

Slacker7, thats not the best of ideas to use when working with cast iron, if the oil drain/supply manifolds have too much force applied to them they could quite easily get hairline cracks in them.. Not a good look.

Much easier to hit it with a hammer, or if you have access to heating up tools then heating them up like NZConvertible suggested is also a good way to go.

 

Are you sure hitting it with a metal hammer is a good idea? Won't that crack it as well? Would a rubber mallet work well to? I have tried hitting it a few time with the rubber mallet and still no go...

 

No, because your hitting the whole turbine housing, not just the center section, or more specifically the oil supply/drain manifolds, which are infinitly more weak the the whole cast turbine housing.
Metal ended hammer will make it resonate alot more than a rubber one, which sometimes will make it come off easier.

 

I dunno if hitting it with a hammer is a good idea either.  You could easily damage the turbine wheel (and shaft) when the turbine housing suddenly releases from the CHRA.  The turbo design is such that two bolts opposite of each other are centered under the oil inlet and outlet flanges.  I just unscrew the bolts and use the flanges to help push the turbine housing off.  Make sure you unscrew the bolts evenly, as to put even pressure to remove the turbine housing!


-Ted

 

Either way it will come off only as fast as you allow it?? what I did was have it sitting with the exhaust wheel pointing down towards a table and the housing partly resting on it then tapping it with a hammer until i got movement, theres no need to bash it silly until it flys off!! you just need to get it moving a bit until you can rotate it.

 

Hmmm, I tried both and still cannot seem to get it to move, not unless it moves very very very slowly....

 

There are different types of cast irons some of which are considered ductile. Two of the ductile type cast irons are pearlitic ductile cast iron and ferritic ductile cast iron (obtained when the iron is desulfurized). Looking at the center section I would have to say that it has to be one of these. (I could be wrong)

Anyway.. talking about causing cracks in cast irons, I would think that it could take more compressive loads than impact loads which are associated with using a hammer. When you use those screws it won't put much stress/strain on the center section. It will only put as much stress/strain as it takes to slowly pull the center section off of the turbine/compressor housing. As far as heating it up with a torch, well.. if you can't heat the thang up evenly you might get warpage.

 

Your 100% right about the fact that pearlistic iron is good in compression and has a high grapthie content which helps against cracking, if it IS pearlitic iron, which im not actually sure the CHRA is.... i'd be leaning towards some sort of Acicular iron due to its lower cost.....

The exhaust housing however, is definatly a type of pearlitic iron because it needs to stand up to around ~1000deg heat, so hitting the pearlistic exhaust housing with a hammer would be fine since its good in compression.

Where as even if the CHRA is pearlistic iron you are exerting a relativly big force on a small area 30x40mm? where the oil drain/supply manifolds are.. or you could exert a similar force on a much larger area...

I dunno its been a while since i've done a materials course.

 

Err.. actually I cheated.. I'm currently working on some papers right now and I had the reference right in front of me .

But I don't think it's going to damage the center housing by slowly unscrewing those bolts. There wont be much stress applied on the oil inlet and outlet flanges because stresses will be relieved as the center section separates from the housing.
Impact loading is bad. However with what you are suggesting I doubt it would cause any damage. Just that as reted suggested that you could damage the turbine wheel if the housing just pops out.