Miata Turbo Forum - Boost cars, acquire cats.

Miata Turbo Forum - Boost cars, acquire cats. (https://www.miataturbo.net/)
-   DIY Turbo Discussion (https://www.miataturbo.net/diy-turbo-discussion-14/)
-   -   SR20 T25 disassembly help (https://www.miataturbo.net/diy-turbo-discussion-14/sr20-t25-disassembly-help-63552/)

curly 02-15-2012 11:39 AM

SR20 T25 disassembly help
 
Yes I read SamNavy's rebuild instructions, and yes, I've searched other dis assembly threads.

So far I've gotten the C-clip, compressor housing, compressor wheel nut, and compressor wheel off. I cannot for the life of me get the CHRA out of the turbine housing. One of the four bolts and one of the half rings is removed, the other three bolts are backed out as far as I can go, they're all hitting the castings for the oil drain and water inlet/outlets. I have put a 2' socket extension in the oil drain hole, put a 3' length of pipe on the end of that, and pried as hard as I could with the turbo bolted to my drill press table and all I did was bend my extension. I should be able to rotate this, yes? Is it easier to twist it back and forth to get it out, or just bang/pull it straight out? I haven't tried any PB blaster here.

And would smacking on the turbine shaft help, or would I just be ------- up seals and bearings. (which I'm replacing anyways.)

I also have a stuck stud on my DP flange. I have enough exposed to get decent grip on it with the vise grips, but it's not working. I haven't tried PB blaster here either, but I have tried wax, a hot stud, and a frozen stud+some heat on the housing. Any other suggestions?

rharris19 02-15-2012 11:41 AM

When I did mine recently I had the same issue. I just soaked it in PB overnight and hit a rubber hammer on the side of the CHRA in the morning. It came right out.

blaen99 02-15-2012 11:44 AM

PB blaster the hell out of the turbine, put the CHRA in a vice, use deadblow hammer, whack the ---- out of it. Don't ---- around with prying, it's not the right "type" of force.

Do NOT touch the shaft, it won't help anything beyond you potentially needing a new rotating assembly. This is BAD.

As for the stud, easy out it. It's your best option if vice grips won't work.

Braineack 02-15-2012 11:53 AM

soak it and try again. a few light blows with a rubber mallet on the end of the turbine wouldn't hurt to help it out. Or I hit the back of the compressor housing on mine sometimes. But yours is probably rusted together, and they are already very tightly fit together once they get snugged down so you just gotta work on getting it to release. You'll get to the point where one side with finally give and then you can work the other side and finally get it to pop.

thirdgen 02-15-2012 12:00 PM

I had the same issue...soak it overnight, or if you're impatient like I was, use an oxy/ acetylene torch with a fine tip and throw some heat in the groove. A Little Heat. Hit it with a rubber mallet and it should fall right out.

sixshooter 02-15-2012 12:11 PM

If the bolts holding the turbine housing to the chra are backed out with the tops of their heads tight against the chra it won't come loose because you have created a wedge. Screw them halfway so they are loose and then bump the turbine housing gently with a small sledge or whack it hard with a rubber mallet.

soviet 02-15-2012 12:21 PM

loosen the bolts a little bit
put the chra into a vice, smack on the housing with a mallet till it turns.
once you can turn it, get all the bolts out. you can rotate the housing so the bolts can be removed.
then, smack the housing some more

thirdgen 02-15-2012 12:43 PM

All this SR20 turbo talk makes me want to keep mine...
Undecided...
Perhaps a poll will be upcoming....

duffbuster243 02-15-2012 02:41 PM

Keep turning the bolts against the chra. They are supposed to press the exhaust housing off the chra as you turn them. I have done this on about 4 different t25's and it has always worked. You want to do it evenly though as to not damage the turbine.

Braineack 02-15-2012 02:46 PM

wait, that's just smart.


:brain:

curly 02-15-2012 07:08 PM

I tried that, one is barely hitting the water inlet, and if I keep turning it itll damage the sealing surface. So I only have two that can push, and they're both on one side, which I'm afraid will just wedge it more.

My stupid vice is two short to hold the chra, I'm already leaning against my miata with a motorcycle between me and the drill press table. I'll try some on blaster and try again.

viperormiata 02-16-2012 02:00 AM

I had the same issue with mine years ago. I don't have a vice, so I heated it up with a torch then beat it with a rubber mallet.

thirdgen 02-16-2012 02:05 AM

Post 5 and 12 have 1 thing in common...win.

curly 02-16-2012 02:42 AM

Yup I'll pick some up tomorrow, torch it, and beat it.

How long are you torching it for? I feel like I'm doing it for a long time, but a hunk of iron like it is acts as a good heat sink. Should I stick it in the oven first? I am in a chilly garage.

thirdgen 02-16-2012 02:53 AM

I didn't torch it till it glowed red...just torched it evenly around the seam where the CHRA and turbine meet. I'd say I torched it until it had that heat discoloration, then I gave it a good whack with a rubber mallet (not a little love tap), and it broke free and pulled right out.

dgmorr 02-16-2012 11:36 AM

I used a regular plumbing style torch and warmed up the turbine housing around where it meets the CHRA. I thought it had welded it self together, but with the heat it just took a few taps with a dead blow. Chemicals did not work for me.

samnavy 02-16-2012 11:55 AM

This is a problem. You're gonna need to hit the CHRA hard enough that it will do damage to the bolts or threads when it pops off and the only thing holding it to the CHRA are 3 almost backed out bolts.

PB Blaster and Liquid Wrench bath for 24hrs.
Then put in Freezer overnight.
Next morning, clamp turbine housing in BIG ASS VICE tight as hell so it won't move no matter what.

Now, hit the turbine housing near the groove with a torch for a few minutes, trying not to get any heat on the CHRA.

Then... BIG ASS RUBBER MALLET as hard as you can on the CHRA. I think I put a piece of wood on the flat mating surface of one of the ports to prevent damage.

If that doesn't work... get a 3lb hand-sledge and tap-tap-tap-tap-tap-tap-tap for a few minutes around the CHRA hitting it from all angles. Then try the rubber mallet again.

Careful with your sledge taps as the CHRA cannot hurt the hammmer... but you can hurt the CHRA if you strike any part of it too hard with too heavy of a hammer.

curly 02-17-2012 04:12 AM

insert manly voice here
 
10 Attachment(s)
I AM ALL THAT IS MAN!

Aka: I got the bitch apart. First off, here's where I'm working, which is where half my frustrations come from. You can see the turbo on the drill press work bench. It's raining outside and that's not even my dirt bike, so putting it outside wasn't an option. Could have put the miata outside, but it has no engine until I get my new turbo stuff, so it'd be a bitch to push it back up my driveway into the garage.
https://www.miataturbo.net/attachmen...ine=1329469927

And here's how I got it off. I tied a rachet strap to a tire iron, prying against the turbine flange, putting pressure on the CHRA. This was hooked to the dirt bike's foot rest. The vice grips are to keep the other end from slipping off the tire iron.
https://www.miataturbo.net/attachmen...ine=1329469927

Used a bolt/nut combo push up on the CHRA against the turbine housing. This is probably the main reason I got this bitch apart.

https://www.miataturbo.net/attachmen...ine=1329469927

Used this little guy opposite my bolt/nut to pry evenly. You can see him pushed against the oil feed casting. I'd go back and forth between the two for a couple turns, didn't take long.

https://www.miataturbo.net/attachmen...ine=1329469927

Unfortunetly, like most projects, once I get past a major hurtle, I forget about the camera and just start tearing ---- apart. 10 minutes later I have this. Hopefully I remember how it all goes together when I get my rebuild kit. The rest is soaking in my carb cleaner bucket.
https://www.miataturbo.net/attachmen...ine=1329469927

TorqueZombie 02-17-2012 04:37 AM

Congrats. Samnnavy's was my suggestion. Cold+heat+hammer would = win. It worked on sand rail turbos that were abused by gorilla's.

blaen99 02-17-2012 05:47 AM

Props for such an unconventional method of seperating the turbine and CHRA.


All times are GMT -4. The time now is 04:37 PM.


© 2024 MH Sub I, LLC dba Internet Brands