ACT flywheel + clutch in... fork snapped!

Flywheel, Clutch, Transmission, Axles, etc...

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free5ty1e
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ACT flywheel + clutch in... fork snapped!

Post by free5ty1e »

This Memorial Day weekend, my friend and I decided to try and tackle the clutch/flywheel replacement job. We had a garage and a decent set of tools, worked under jackstands. It was a pain in the a$$ without a lift and tranny jack, but we managed.

On top of that, we discovered how bad much my clutch and flywheel were. Apparently the last person to replace the clutch decided that instead of taking that heavy flywheel off the engine and resurfacing it with the right equipment, he'd just do a quick de-glaze with a rotary air buffer. Needless to say, he did not do it very evenly. The actual clutch plate looked almost new after over two years of relatively rough driving. Which made sense, as the flywheel wasn't flat enough to wear very much of it.

Anyway, the clutch pressure plate's center retaining ring had a death grip on the throwout bearing -- because once we got everything out of the way and got the tranny loose, we couldn't get that sumbitch off the engine no matter how hard we pulled and wiggled it! It had a hell of a gap and it just wouldn't fall... we actually had to take the 6 clutch bolts out of the flywheel from the topside, turning the engine to access each, and finally we were able to get the tranny to the floor and examine the clutch and snap that damn ring off the bearing. Finally we could install the new parts after an entire day of removing old ones! :)

Everything was going fine until the time came to install the slave cylinder. My clutch system was still full of fluid, we just hung the removed components with bungee so we didn't have to drain that too. This meant that the slave cylinder could not be bolted into place with the clutch fork in the engaged position. So, instead of bleeding some clutch fluid out and compressing the slave cylinder to fit it behind the fork, we got an adjustable wrench on it and pulled it towards the front of the engine. It didn't move too readily, and kinda hurt to pull on that hard, so we put a 2' cheater pipe on it for leverage and I pulled it while my friend installed the slave cylinder. About halfway through the second bolt, it snapped! I picked up the wrench, still holding the top of my clutch fork from the divet up, and stared at it in disbelief. :cry:

We were mid-Sunday by this point, so any hope of acquiring a replacement fork was lost. Eventually, we decided to try and weld the top back on to the fork right there in the car. We didn't have enough time to remove and reinstall the transmission again (nor did we want to) in order to remove the clutch fork and weld it on a workbench.

So, the fork came upward, as far as possible. Out of the throwout bearing, and vice-gripped to suspend it there. Flame-resistant material was bent and slipped behind the fork to protect the engine compartment. The fork was cast iron, so we turned the heat all the way up. It was as clean a break as I'd ever seen, it went back on perfectly. Got welded on the three un-diveted sides, then reinforced with some scrap steel on the two sides we could get to.

Bled some clutch fluid out and compressed the slave cylinder, installed it, finished everything up and bled the clutch system to get the air out. Clutch felt a bit tougher to press, but that was to be expected from the heavy duty pressure plate. It engaged and disengaged without snapping, and seemed fine through an estimated 20-30 shifts so far.

I hope it holds. We've sort of deduced that it it holds up to my standard driving patterns for about a week or so, then it'll probably hold up fine. There is a possibility that it is as strong as it used to be. There is also a possibility that the welds won't hold and it'll break the fork at some point, and I'll have no clutch until my friend's got another entire free weekend to help me install a new fork. Man. I hope it holds.

On another note, the WRX flywheel and clutch seem to be identical to the OEM models, which I believed to be on my '94 SS. Perhaps someone before me decided to replace them with a WRX flywheel/clutch combo? Or perhaps did the '94 Legacy SS have the same size as the WRX? There was no 3mm diameter difference as far as I could tell. Matched perfectly, tooth for tooth, with the 13.9 lb ACT StreetLite WRX flywheel. Although thicker... man that thing was heavy!!

I also replaced my controlled-leak TurboXS MBC with a Dawes Devices cheapest ball-and-spring MBC (think it was like $15-$20 with shipping). It seems to spike much less than the old one, but I still have boost spread. 12-13psi in 1st, 16-17psi in 5th. I've got to get back to work on the LegaCU and try and get the factory boost control up and running so I can get a damn solid boost level in all gears. I'm not dropping the money for an EBC, I'd rather spend that kind of money on a bigger turbo.

Did I mention I also got the Walbro 255lph pump in? Works great... WOT high boost EGTs are down. Guess I might have been starving the #4 injector a bit at times before, as that's the cylinder the gauge is reading (since #4 is last in line for fuel).

If my fork stays together, you can bet I'll be back to work on the LegaCU sometime very soon... I want stable boost, I want digital cab-adjustable boost, and I want more boost. :twisted:
-Chris
91SS 4EAT stock, 200k mi
91SS 5MT rebuilt engine waiting for a shell
93TW 4EAT, Forester lift, 3" TBE, 11psi, 200k mi
94SS 5MT4.11+rLSD 311k km: RobTune550,TD05-16g @ 18psi,FMIC,3"TBE,Forester lift
legacy92ej22t
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Post by legacy92ej22t »

Wow, I'm glad you got it all together. I do have a couple of comments about your post.

I don't understand why you had trouble with the clutch slave cylinder. Mine just went right in without having to compress it at all. Seems weird that it gave you so much trouble. :/

When we did my flywheel and clutch the WRX stuff definitely looked slightly larger in term of the clutch discs CONTACT SURFACE AREA on the flywheel. It's bigger and the clutch disc is bigger. The overall circumfrance of the flywheel is the same though.

I just got my Walbro in too and it does make a big difference.

:D
-Matt

'92 SS 5mt. All go and no show. Sold :(
'94 Audi UrS4 Modded (new project)
'96 Outback 5mt.
'07 Legacy 2.5i SE

[quote="Redlined"]
Oh... and I hope the fucker get bunked with Gunter, arrested for raping Gorillas.[/quote]
free5ty1e
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Post by free5ty1e »

ahhhh... we didn't compare the contact surface areas, I was looking at overall diameter. Nevermind lol

When we were trying to work the two slave cylinder bolts in without moving the clutch fork, it had too much tension on it and the bolts would not go in straight. Man how I wish we would have just bled some clutch fluid first instead of trying to muscle the clutch fork into the engaged position from the topside. Neither one of us could believe that clutch fork snapped like that. I mean, sure, the clutch is tougher to engage now thanks to the heavy duty pressure plate, but thats thick cast iron!

Anyway - I was looking all over the place for the actual proven procedure for clutch/flywheel R&R, and I could find just about everything BUT that. So while I still have it in my head, let me put that down here - in terms the Seach function can find:

CLUTCH REMOVAL STEPS:

1. Remove front wheels

2. Pry up dented side of axle nuts, remove

3. Unbolt brake calipers, set out of the way without stressing brake line

4. Remove alignment / control arm bolts (2 bolts, 14mm?), separate rotors from axle halfshafts

5. Remove drift pins from tranny side of axle halfshafts, pull axle halfshafts out, set aside

6. Drop rear exhaust hangers, support exhaust pipe with something so as not to stress the turbo - you just need to be able to move the exhaust out of the way enough when it blocks access to bolts.

7. Remove rear driveshaft protective plate (6 bolts)

8. Remove 4 12mm bolts connecting driveshaft to rear diff, separate (you will have to turn the driveshaft to access them all, so have the rear wheels off the ground for this one)

9. Get a drain pan, drain gear oil from tranny (drain plug is rather obvious, large, and facing straight down)

10. Remove carrier bearing bolts from driveshaft (2 14mm? bolts), drop driveshaft more

11. Pull driveshaft out of tranny, remove from vehicle

12. Support tranny with a jack, at least somewhat

13. Remove multi-piece crossmember from bottom of tranny (2 17mm? bolts, 6? 14mm bolts, 2 14mm tranny mount nuts) - now transmission is supported by engine and jack

14. Remove first shifter bushing bolt/nut (12mm, may have to lower the tranny's jack a little to access and remove this)

15. Remove other larger shifter bushing from tranny (12mm nut and large, strange lookin washer with a place for a spring, which I don't have)

15a. Remove slave cylinder (2 14mm bolts) from tranny. Remove clutch hydraulics assembly from side of tranny (3 14mm bolts). Hang both out of the way. While you're at it, bleed some clutch fluid out of one of the bleeders by compressing the slave cylinder.

16. Remove starter - first the lower nut (14mm?), then remove the top driver-side tranny/starter bolt (14mm, feels about 3 foot long when you're taking it out). Using bungee, hang starter somewhere in the engine compartment out of the way (or just remove it completely if you feel like it)

17. Remove other top tranny bolt (14mm, also feels about 3 foot long when you're getting it out)

18. Unclip wire connector (grey, 3 wire?) from tranny

19. Unclip speedometer cable from tranny, do NOT lose the small spring that comes out!

20. Remove the two lower tranny nuts (14mm)

21. Here's where it gets fun if you don't have a real tranny jack and a lift... pull tranny off engine and remove from vehicle.

From here you can access the clutch and flywheel. Replace and reverse removal procedure. You'll have to bleed the air out of the clutch system and top it off if your pedal stays to the floor when you press it.

I hope this helps someone else, I sure wish I could have found a procedure like this before I tried my clutch replacement...

If the slave cylinder
-Chris
91SS 4EAT stock, 200k mi
91SS 5MT rebuilt engine waiting for a shell
93TW 4EAT, Forester lift, 3" TBE, 11psi, 200k mi
94SS 5MT4.11+rLSD 311k km: RobTune550,TD05-16g @ 18psi,FMIC,3"TBE,Forester lift
legacy92ej22t
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Post by legacy92ej22t »

One thing to add to your DYI list. You don't need to actually remove the axles. Instead of removing the axle nut, rotors and all that, just undo the camber and guide bolts (2@ 17mm IIRC). This will unhook the strut from the conrtol arm. You can then just punch out the axle pins from the tranny side of axles and pull them out from the tranny and support them on the cross member.

This will save a lot of time and they really don't get in the way of the job either.
-Matt

'92 SS 5mt. All go and no show. Sold :(
'94 Audi UrS4 Modded (new project)
'96 Outback 5mt.
'07 Legacy 2.5i SE

[quote="Redlined"]
Oh... and I hope the fucker get bunked with Gunter, arrested for raping Gorillas.[/quote]
BAC5.2
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Post by BAC5.2 »

All suspension adjustment bolts are 19mm, just like our lug nuts :).
2009 Outback 2.5XT. 5MT. Satin White Pearl.
2009 Impreza 2.5i Premium. Blue.

[quote="scottzg"]...I'm not a fan of the vagina...[/quote][quote="evolutionmovement"]This will all go much easier if people stop doubting me.[/quote]
free5ty1e
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Post by free5ty1e »

Excellent... thanks for adding to/correcting my clutch installation procedure. I will be driving my car again soon today, I hope the recent downpour that rusted my newly-de-glazed brake rotors in a single night did not affect the clutch fork welds at all.
-Chris
91SS 4EAT stock, 200k mi
91SS 5MT rebuilt engine waiting for a shell
93TW 4EAT, Forester lift, 3" TBE, 11psi, 200k mi
94SS 5MT4.11+rLSD 311k km: RobTune550,TD05-16g @ 18psi,FMIC,3"TBE,Forester lift
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