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CT26 Rebuild - How To... by Robert Pina

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#1 · (Edited)
CT26 Rebuild - How To...

While looking around I found this walk-through on how to rebuild your CT-26 (assuming you are NOT swapping wheels, and do NOT have a scored center section on the turbine shaft). It was graciously translated by Robert Pina years ago for AllTrac.net

GREAT Walkthrough. Convinced me to rebuild my own turbo or at least buy the parts to rebuild my original 57 trim that I like better than my current 57 trim. It had a WAY snappier/instant kick you in the ass boost curve. This one is smoother, and if I wanted smooth, I'd get a lexus or something.

http://www.alltrac.net/tuning/turborebuild.html

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COPIED FROM Alltrac.net

ps. I have saved these pics and will re-host if necessary and Alltrac.net ever goes down.
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Rebuilding the CT26



Introduction



In ordinary situations, the owner of a car does not rebuild his own turbo. However some have noticed that just a short time after having their CT26 rebuilt or upgraded, the seals have blown and oil is leaking. It is not necessary to do a full rebuild in this case, so a simple seal replacement is in order. Doing this step is easier than you might think. A complete rebuild can be done in some situations however, a really bad turbo must be upgraded by a professional. With this in mind, here is somewhat of a guide for you when attempting this procedure.




Before we begin, take a second to familiarize yourself with CT26 and it's parts. There are 3 main parts:

  • Compressor Housing
  • CHRA (Center Housing, Rotating Assembly)
  • Exhaust Housing


Compressor Housing



While the first and last are obvious, the CHRA is basically everything inside. From the compressor wheel, to the turbine on the exhaust side,
and the bearings seals and actual center section. The bearings in the CT26 are of a floating type. Which means they "float" in a coat of
oil. That's why with this turbo, it's very important to always run clean oil and follow proper cool down procedures.



Here's a layout of the supra CT26 (courtesy CJsupra). If you were to buy a CHRA (pictured) it comes rebuilt and assembled. The exhaust, compressor

housings have been ceramic coated, as well as the turbo elbow. There is a bag of new bolts from Toyota (recommended), and in the bottom right is

the clamp that holds the CHRA to the exhaust housing.



Journey into the unknown...



One thing to keep in mind is that the turbocharger requires a precision balance since it spins in excess of 100,00 RPM. If you do something to upset this balance, you can have a new hole in your turbo where the compressor used to be. Please be careful. Please do not hold us responsible. For the most part replacing just the seals is no problem. Attempting to repair a turbo with excessive play is very hard to do properly.


Disassembly

  1. Remove Turbo Clamp covering center section (2x12mm Bolts)
  2. Heat the connection between center section and exhaust housing (Hair dryer)
  3. Knock exhaust housing free using mallot, or drive a piece of wood in between to wedge the pieces apart (Bigger Hammer sometimes required)
  4. Examine exhaust housing for cracks, replace if necessary
  5. Use some large needle nose pliers or something similar to undo the large C-clip holding on the compressor housing
  6. Remove the compressor housing seal using a small pick
  7. Mark the position of the compressor wheel to the mounting nut and turbo shaft. Must be re-installed in the same position.
  8. Place turbine side in workbench vice upright, remove turbo nut. (10mm if previously rebuilt, otherwise SST for toyota nut, or vice grips)
  9. Remove compressor
  10. Needle nose pliers again to remove small C-clip
  11. Remove top bearing (may require vice grips to pull up)
  12. Remove inner oil seal
  13. Remove washer
  14. Remove Bearing
  15. Remove Center Section from Turbine
  16. Clean and examine Turbine
  17. If the inside of the center section is scored, it must be re-bored by professional
  18. Assemble in reverse order, coat parts with fresh oil
  19. If you removed Toyota compressor nut, replace with new.


Parts Source

USA:

ADP @ 1800-225-3596...ask for Darell
$107.75

Canada:

Bramall Turbo Supply Ltd.
bramall@bramall-turbo.com
119 Spy Court
Markham,Ontario
Canada. L3R 5H6
Toll Free: 1 (800) 567-7559
Phone: (905) 477-7559 Fax: (905) 470-0618

CT26 Repair Kit PN# CT2003

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It's me Rusty now.

That being said...

I would scribe the compressor nut with a razor knife or a VERY FINE tip Sharpie.

I did some reading and on SupraMania they said to use as big a hammer as you feel comfortable (more or less you have to beat the ever living shit out of the exhaust housing to get it off).

Also I would use a heat gun, not a fucking hairdryer on the exhaust housing. Really!!? a blow dryer?

I am ordering a rebuild kit tonight (From Driftmotion.com, who has a custom billet seal plate), and overnighting it to me here in Louisville. Expect a rebuild thread with pictures AND video in the coming weeks.

Peace.
 
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#2 ·
Dude, thanks for the post. Not many people have the courage to undergo something like this.. Good luck!
 
#3 ·
Oh, and was kmfdm killer mother fucking dance mix, or was it ketchup made from dead mice...

Onoo I remember now.. Karl Marx found dead masturbating.

On that note Im going to look for my symbols CD..
 
#4 ·
Thanks man.

CT26 Spec's per MKIII TSRM

NO MORE THAN:

0.13mm Axial Play (in/out/front/back) - 0.0051"
0.18mm Radial Play (side to side) - 0.0071"


If more play than listed, a rebuild is necessary (according to the TSRM).

These are the pieces normally found in a CT-26 Rebuild Kit:


Here is an exploded diagram of the CT-:
 
#7 ·
nice, this is interesting...
 
#8 · (Edited)
FWIW, I did not "do" the original write up. I found this write up, on a site in Japan, in ~2002. I translated the text and re-hosted the pictures back then.

That said, I'm glad that the information is being put to use, and being updated to what is available today.

I think many people don't realize it's pretty easy to take apart a turbo. I recently replaced a chipped compressor wheel on a CT26 with a good one and everything works great.

There is actually a good video of a CT26 rebuild, that was attached to this original page. It was an MR2, but it was interesting to see the turbo being taken apart, upgraded, and balanced by the shop. If I can find it, I will add it to this post.

I would take the name out of the write up, since I was not the original author of the write up.
 
#9 · (Edited)
I rebuilt a couple of CT-26 with this very helpful article as reference a few years ago, the hardest part is to seperate the exhaust housing and center section, it took some good poundings with a copper head hammer before they came apart, make sure to clamp the center section down with a good solid vise, the rest is straight forward. If the old turbo already has excessive radial play, just replacing the bearings with the kit may not bring it back to spec. Chances are the bore in the center section needs to be reamed and use an oversized piston ring on the hot side, supermania has a good sticky in the turbo section on how to do this.
 
#11 ·
More Info...

http://www.turbobygarrett.com/turbobygarrett/tech_center/acronyms.html

VERY good bit with acronyms etc.

I JUST found out WTF "Trim" means, as in a 57 trim, or 60 trim turbo. FINALLY... I'm understanding more & more YAY for knowing more about turbo-techno-wizardry. SOMEDAY people will say my engine is demoniacally powered!! (demon powered)

Trim

Trim is an area ratio used to describe both turbine and compressor wheels. Trim is calculated using the inducer and exducer diameters.
Example:
Inducer diameter = 88mm
Exducer diameter = 117.5mm
Trim = Inducer2/Exducer2
Trim = 882/117.52 = 56 Trim
As trim is increased, the wheel can support more air/gas flow.

SO... Trim doesn't have a DAMN thing to do with A/R.
 
#13 ·
I did this rebuild using the same instructions about 8yrs ago, I did it perfect as I could find, it still leaked oil a lot.
Years later I was at a turbo shop and they told me toyota turbos are notoriously hard to rebuild as the clearences have to be perfect, Mitsubishi turbos are much easier her told me.
Best of luck on it! will be awesome if you get it to work!
 
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