T25 disassembly

[jdm'95gst]

I searched on this site and googled for a T25 disassembly diagram/how-to/instructions. I've seen it somewhere, but I just can't find it. Does anyone have the link, or knows how to, please let me know.

The reason I'm disassembly the T25 is because I need to replace a few of the seals, and check the inside's condition to see if anything else needs to be replaced.

Thank you for any help!

 

[ILLiCliPSE]

I need to know the same thing:

Im swapping exhaust housings from my t25 to my t28...since theres a broken bolt in one of the holes in the housing of the t28, and Im just swapping the housings since theyre the same. I started to unbolt the housing, but the bolts have no way out since they hit some of the components of the center section of the turbo.

 

[jdm'95gst]

I'm on the same boat. I started to take those bolts off but they all hit the center of the turbo. I was only able to take off the wastegate.

 

[ILLiCliPSE]

We literally have the same problem . I only was able to take off my wastegate as well. SOMEONE HELP US!

 

[ILLiCliPSE]

some one please help! im trying to get this t28 installed tomorrow! but i need to do this first!

 

[jdm'95gst]

Ok I found out how. After taking a close look at the turbo, the compressor side is held on by a snap ring (you'll need a snap ring pliers).

 

[fwdeclipse]

Its not hard there is a large c clip that holds the compressor on,and I think like 4 bolts on the turbine side to take off.

 

[jdm'95gst]

yep! it's all apart now being rebuilt and ported and polished!


don't worry, i'm not pimping this turbo out to go back on the DSM, it's going on my daily driver

 

[turbosax2]

I'm having the same problem too. I broke a few pairs of snap ring pliers trying to get the c-clip off, so I need to get a decent set first. But once I get the compressor housing off, how do I get the turbine housing off? Three of the bolts only back out so far before they hit the center section.

 

[JusMX141]

I'm having the same problem too. I broke a few pairs of snap ring pliers trying to get the c-clip off, so I need to get a decent set first.

The steel snap ring corrodes into the groove in the aluminum compressor cover. You'll NEVER get it off with snap ring pliers.

I've already broken the tips off of long-handled needle-nose pliers like these while trying to remove T25 snap rings:

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The only way I've found to do it is to clamp the whole turbo (turbine housing removed) into a soft-jawed vise and begin trying to compressor the snap ring using a hammer and a punch. There's enough corrosion in the groove that the ring will not try to spin while I do this.

Once you compress the tips of the ring together a bit, the base of the ring will pull out of the groove which allows you to get a thin screwdriver underneath the ring and begin to pull it outward. Be careful....once it pops, it POPS. Be sure to wear safety glasses / goggles.

Once I get the ring out of the groove, I media-blast both the ring and the groove in the compressor cover very well. Installation is a breeze with snap-ring pliers once all the corrosion is removed.

But once I get the compressor housing off, how do I get the turbine housing off? Three of the bolts only back out so far before they hit the center section.

You should remove the turbine housing FIRST. I normally back all of the bolts out as far as possible, then use a dead-blow hammer (hits harder than a sledge without damaging the housing) to jar the turbine housing loose. Once it pops loose, it will drop down enough to give you the clearance to get the bolts the rest of the way out. It also allows the housing to rotate 360* to access the bolts a little easier.....but this adds a whole degree of difficulty getting everything to line up during reassembly.

Be sure to mark the orientation of EVERYTHING before you tear this turbo down!

 

[OddNotion]

I had to use the same routine with the hammer and punch on the snap ring. I just put the tip of the punch in the hole and pounded on it in a fashion that simulates trying to compress the snap ring. It took a lot of work and PB soaking. I also had success with a large pair of 90 degree needle nose pliers, which I set into the snap ring holes, and closed/compressed right above where the pliers stuck into the holes with channel locks rather than the handles of the needle nose themselves. This was the needle nose doesn't flex and bend as you squeeze the clip. It wasn't a one shot deal, but it worked finally.

I too removed the turbine housing first. I loosened the 4 nuts, removed the ones I could, and dribbled generous quantities of PB all over the area where the CHRA and Turbine housing meet. It took like a day and a half of occasionally reapplying the PB until a bunch of soft taps from a framing hammer on the various "safe" parts of the two pieces started to render some movement. Once the two come apart some more you can loosen the nuts and keep going until you get it apart.

 

[turbosax2]

Be sure to mark the orientation of EVERYTHING before you tear this turbo down!

I'm only taking off the compressor housing (to media blast) and turbine housing (to polish). Do I still have to mark orientations of anything? Don't you only have to do that if you are rebuilding the turbo?

Thanks for the help guys.

 

[JusMX141]

I'm speaking of marking the orientation of how the compressor and turbine housings align on the center housing....not the orientation of the wheels on the shaft.

 

[turbosax2]

Ah, gotcha. Will do.

 

[turbosax2]

I got the turbo apart. After much PB blasting and banging the turbine housing with a rubber mallet, the housing finally separated and I could tell it was loose. It was very unspectacular. I then proceeded to loosen the remaining 3 bolts and pull the housing straight off the center section. And I found this:

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Every time I PB blasted the turbine housing, I also sprayed the snap ring. Once I got the turbine housing off, I went to work on the snap ring. I followed the advice given above and used a mini sledge hammer to hit a punch placed in one of the holes in the snap ring ends. Instead of the snap ring compressing, it started to rotate around so I could not use the punch/hammer to remove the snap ring. Then I followed the other advice given above and used vice grips to squeeze down on snap ring pliers. After a few tries I manged to get the snap ring out, then pulled the compressor housing straight off the center section. The compressor side looked fine to me:

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A little history on this turbo:
It is the original turbo on my 99 GSX and has 97,000 miles on it. My car has been bone stock its entire life (so the turbo was always at factory boost levels). The turbo pulled fine and never smoked when I drove it. Before I took the turbo off the car this summer, there was no in-out shaft play and little to none side to side shaft play. Now (the turbo has been off the car for a couple of months), there is a little bit of side to side shaft play (which I think is due to no oil present). I have not touched the turbo since it has been removed from the car until a couple of days ago, just to remove the turbine and compressor housings. The broken piece spins freely and can be lifted up slightly. I can make it sit so that the shaft spins freely and none of the blades hit the broken piece, but most of the time the blades will hit. Just before I disassembled the turbo today the shaft still spun freely. None of the blades on the exhaust side appear to be damaged from hitting the broken piece.


My questions:
1. What is the broken piece called? I believe it is the heatshield?
2. How could this have happened?
3. How serious is the problem and could the car be driven with the turbo like this?
4. Can this be fixed easily or would the turbo need to be rebuilt? I don't think rebuilding this turbo is cost efficient so I would like to avoid that.
5. My friend has a T25 that he would probably give to me for free. Can I swap my compressor and turbine housings onto the center section of his turbo if his is in good condition?

If you need any more pictures to make a diagnosis, let me know and I will take them.



And one more question:
Is it normal that the wastegate flapper gets stuck to the side of the housing if I lift it to almost 90*? I didn't pay attention to how it acted before, and I think I might have set the turbo down on the wastegate flapper on accident once. Or does the stock wastegate not have enough travel to open the flapper this far?

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[OddNotion]

Eric, the wastegate flapper will hit the housing and that is normal. It never actaully opens that far so it's of no concern to us (or the engineers apparently). You can verify that by moving the wastegate arm when it's all together. I read that in the porting VFAQ.

Your broken heatshield is scary. It looks like something came OUT of it (Aliens chest-burster) and you will have to unbolt the compressor wheel from the turbine to get it off. If one of the little slivers eroded more and flaked off, it would blow into the spinning turbine, which may not be a big event since some of it obviously has already. It's possible that something from somewhere in the engine came down into the spinning turbine and got kicked out at ballistic speeds into that heatshield. It's weird how the hole seems angled in the same direction as the trubine rotates, possibly negating my previous suggestion.

I now have 3 T-25s because the first two I bought had really bad shaft play. The third one has NO play. The first one has a great, non-rusty turbine housing and I started polishing the compressor cover, so I'm transplanting the good CHRA from turbo #3 into the compressor and turbine housings of turbo #1. You should too rather than disassemble a good CHRA.

 

[JusMX141]

My questions:
1. What is the broken piece called? I believe it is the heatshield?
2. How could this have happened?
3. How serious is the problem and could the car be driven with the turbo like this?
4. Can this be fixed easily or would the turbo need to be rebuilt? I don't think rebuilding this turbo is cost efficient so I would like to avoid that.
5. My friend has a T25 that he would probably give to me for free. Can I swap my compressor and turbine housings onto the center section of his turbo if his is in good condition?

And one more question:
Is it normal that the wastegate flapper gets stuck to the side of the housing if I lift it to almost 90*? I didn't pay attention to how it acted before, and I think I might have set the turbo down on the wastegate flapper on accident once. Or does the stock wastegate not have enough travel to open the flapper this far?

The broken piece is indeed the heatshield. I have no clue how this might've happened because it's opposite of the direction that the turbo rotates. Obviously the turbo has been like this a while, so I really think it's not going to effect it in any way....although I'd use something to pound it flush so there's no way it could make contact with the turbine wheel in the future.

Paying to rebuild a T25 isn't really cost-effective for DSMer's (you can upgrade for about the same money), but if you're willing to try to rebuilt it yourself you can do it for the cost of the parts kit (around $75.) You mentioned that the turbo has mileage in the 90's which is pretty low, and as long as the car has had synthetic oil the whole time it's been on the road I wouldn't worry.....but T25's only have a 270* thrust plate and are known to develop in / out play in a hurry if something disrupts the oil flow to the turbo.

Personally, I'd rebuild it just to be on the safe side. It would be like buying an engine with reasonably high miles and just dropping it right into your car....wouldn't you rather rebuild it while it's out and easy to rebuild?

The actuator never allows the flapper to travel far enough to snag the housing. At best, the flapper opens 1/4"-3/8" under full boost.

 

[turbosax2]

Thanks again for the help guys. Justin, I have no idea what oil has been ran in this car since I just bought it last December and have only driven it a few hundred miles since then. I'm going to get my friends turbo and take it apart. His has more mileage than mine (maybe 120k) but if it's free and in good condition, you can't beat that. Is there anything else I should be looking for to make sure his turbo is in good condition? I know he beat on his car more than I have on mine since he has upgrades, but the turbo was in good condition before he pulled it off a couple months ago and it has little to no shaft play, just like mine does. If for some reason his isn't good to run then I'll consider rebuilding the turbo - I just hate to put any money into such a tiny turbo

Erin, that Aliens reference made me chuckle

 

[JusMX141]

I'm going to get my friends turbo and take it apart. His has more mileage than mine (maybe 120k) but if it's free and in good condition, you can't beat that. Is there anything else I should be looking for to make sure his turbo is in good condition?

I'd get his turbo and rebuild it; then if you run into a problem, you always have yours as a backup. It's a good learning experience, and that way you'll be sure it has all new parts and is ready to roll.

Here's some guidelines when inspecting a used turbo:

http://www.dsmtuners.com/forums/tur...-what-worry-about-when-buying-used-turbo.html