Replacing my OEM clutch Friday

Working with an 06 5mt GT on Friday replacing the OEM clutch (I'm assuming) at 95k. I bought the car with 76k on it and from my understanding from doing all the labor on it since purchase, it was not stock throughout its past life. The reason for replacement is the TOB is making its death knell noise, so I want to replace it before it seizes and grenades my trans snout. I think the clutch also slipped once last week, but I'm not entirely sure.

 

A coworker got me setup with his hookups on parts so I got myself screaming deals on:

• OEM 06+ WRX SMFW
  
• OEM 06+ flywheel bolts (8)
  
• Extra-S (4qt)
  
• T-70 Torx for trans
  
• T-50 Torx "Plus" for OEM 05/06 LGT flywheel bolts
  
• Clutch Masters FX250 kit
  

 

About the clutch: I called Clutch Masters directly and was assured that the FX250 is what I want/need. I was told it is rated for 70% above stock which works out to about 425tq crank. That's about what a VF52 will do balls out (I plan to tune conservatively considering it's my DD) and that's my plan when/if my VF40 goes. The 350 is rated for 110% over stock or 525tq crank which in my opinion, is far too much clutch. There's only so much torque available at normal engagement (such as in traffic or at lights) and the more aggressive 350 would not slip enough to allow for smooth engagement. Word on the street is that aftermarket clutches are also underrated by 15-20% which doesn't mean I'm going to intentionally make more power than its rated for, but that I feel safer there's a little wiggle room above my power goals.

 

I know there are people claiming they make 330whp/tq on a VF52, but I'm betting that was on a DynoJet which are known to read high. I have a baseline of 231hp/233tq on a Cobb OTS stage 2 map with a full 3" exhaust and Cobb intake with 70F ambient on a SuperFlow AWD chassis dyno regarded as the most accurate out there. I have a hard time believing an OEM upgrade turbo can give me 50% more power at the wheels with an appropriate tune.

 

Things I'm concerned about:

In the past week or so, my TOB has started making MUCH more noise than previously. It's got me thinking about the trans snout. I know everyone (well, vast majority) just say "Slam a TSK3 kit on there and button 'er up" but I'd rather not buy parts if I don't need them. I elected not to get it considering it's an extra $150+ I might not need on top of it being a weaker TOB. My clutch pedal feels smooth both with the car running and off. It makes squeaking noise within the pedal box, but it moves consistently which makes me think the snout is not scored/galled.

 

The questions:

How many of you have actually needed the TSK3 kit?

 

What type of grease do you put on the snout before putting the TOB on? I know I only need a thin film, but is there any preferred type?

 

Any tips?

 

I already know about putting anti-seize on the mating surfaces (engine/trans) and the dowel pins when mating it back together. I also know to pay attention to turbo clearance but it should be fine because the turbo hasn't been removed/replaced to my knowledge. I refuse to put anti-seize on any of the clutch and flywheel bolts because not only does it make it easier for them to back out, but it makes it easier for them to be over-tightened (lubes the threads).

 

I have watched the Scruit put up in the stickied thread a couple times. Is there any thing he missed or needs elaboration? I noticed he didn't really show disconnecting the shifter linkage - is that self-explanatory as soon as I see it or is there a "best" way to do that to ensure it doesn't come out of adjustment?

I use a high grease. Any auto parts store will have some. I get mine from Tractor Supply.

 

Oh grease the starter shaft too. I also put a little on the ID of the pilot bearing.

 

Sounds like you have everything else.

A high grease?

A high grease?

 

 

I'm assuming he meant high TEMP grease.

I grabbed a moly fortified axle grease... seems to be fine but I've only got 200 miles on the clutch so far.

 

Copy/paste from the "What did you do to your 4th gen" thread:

 

Installed my clutch yesterday (11/29) with the help of four friends.

 

Got to my friend's house around 8:30am to get the kerosene heater fired up and the garage warming. It's an insulated garage but doesn't have a heater installed yet. Got the car in the air on all four corners, pulled the trans plug and let it drain while we ran out to get some breakfast, axle grease, loc-tite, and brake cleaner. Came back and set to tearing apart the engine bay and the part of the downpipe I could reach from the top. Flipped and started working on the underside removing the downpipe, heat shield, center driveshaft and after supporting the trans with a jack, the trans cradle.

 

After cracking the last bolt on the subframe loose, it almost smacked me in the face. "I'm not sure why I forgot about gravity for this last bolt...."

 

Separating the trans from the engine was a PITA. We got it apart around 4pm and I removed the stock clutch and pressure plate. The friction material had all of the grooves in the material worn off on the pressure plate side. The flywheel side didn't look horrible but it wasn't BNIB either. Flywheel didn't look too bad. Pressure plate looked fine other than the TOB wear on the spring fingers. The TOB... LOLOLOLO "Skateboard wheel" doesn't even begin to describe the bearing noise. Just throw a handful of loose ball bearings into the washing machine and set it to the spin cycle. It went from "I think it's making a whirring noise" to "HOLY EFF Get this thing out of my car NOW" overnight pretty much.

 

Reassembly went pretty smoothly up until mating the trans to the engine. We couldn't wiggle it in on the bottom enough so we started cinching it up with the trans bolts until we could get the nuts on the studs. Then I heard a pop and thought of Nolmers... I'm still a little paranoid I destroyed the inner rate of the pilot bearing with the input shaft. I'm not getting any weird noises so maybe the pop was more of the pins on the bell housing meeting up or something. I'm second guessing myself on tightening the pressure plate bolts... I'm sure I got them all but I always fear I forgot one.

 

Trans was mated up and bolted tight and everything reinstalled and buttoned down tight. First start up with the hood open told me one of my accessories has bearing taking a dump so I might be doing an alternator or something soon. Finished around 10:30pm.

 

Now, for the people wanting to know about the FX250:

 

Clutch pedal is... soft. WAY soft compared to stock. Way. I'm having to re-learn my muscle memory for where it grabs and whatnot. I've caught myself over-revving a couple hundred rpm when shifting because the clutch is disengaging faster than before. I'm about 50 miles into my break in period, but most of that was 55mph country roads coming home from my friend's house... I'm probably going to break it in to 750 miles or so considering my city/highway split. I seem to remember my Clutch Master's booklet telling me 500 miles of city driving for the break in.

 

Back to the clutch. Pedal is soft, TOB slides nice and quiet (no TSK3 needed), and it grabs pretty hard for new. I almost stalled it the first time I tried to back out of the garage.

 

TL;DR crew:

Clutch is in. Never doing that job myself again. Feels good. Almost stalled like a noob. Not everyone needs an FX300/350 for stage 2. My whole body hurts.

Thanks for the update.

I know your still new on the break in but hows the engagement? Smooth? Chattery? Grab and let go till engaged fully? I had a bear of a time with my FX100 and actually sent it back because he "rebuilt" it once and it still felt like a semi-metallic friction surface and would shake the engine violently when engaging, Only once warm though... figure that out.

 

I'm back to an OEM clutch and its lovely... I doubt it will hold my 255/310 power output for long but at least for now it's good... Still debating on what clutch to end up going with in the end.

 

Once you get good clutch swapping is rather quick... alone I started at 1PM and finished at 7pm, That was leaving the trans in the tunnel too, just supported by jacks. I separated the engine/trans then pulled the FX100 out, left the flywheel in place... only had 3k since surfacing and just dropped the OEM clutch back in place. I did that all last Tuesday the 19th.

I'm also interested in the continued use and opinions of the FX250...

Engagement from a dead stop (or on a hill) is still a bit rough. I've got about 3600 miles on it with most of that being city driving.

 

If I'm beating on it, it's nothing short of a dream. As long as you aren't dumping it, it's great. Aggressively letting it out is smooth. Normal driving is fine aside from the dead stop starts.

 

I've slipped it once pretty good being a moron in the snow... smelled clutch for a couple days but it's back to normal.

 

Pedal feel is great - lighter than stock and perfectly linear.

 

I'm not sure how much I believe people saying their 300/350 engages smoothly with a stock/stage1/stage2 tune... there's just not enough power at engagement to slip it enough to have a smooth engagement unless you consider holding 3000rpm while letting it out.

 

I'm not sure how much I believe people saying their 300/350 engages smoothly with a stock/stage1/stage2 tune... there's just not enough power at engagement to slip it enough to have a smooth engagement unless you consider holding 3000rpm while letting it out.

 

No problems here with Stage II 5th gen's low RPM wTQ. That 500 city miles break in translates into 2000 daily driving miles. It takes a long time.

Yeah, but you 5th gen guys have way more torque down low than us 4th genners.

Well, 5th gen does give up wHP on the top end unless the TMIC is replaced. But that does not affect the clutch

baconbits,

 

I know you said you didn't go with the TSK3 kit due to not wanting to spend money on parts you don't need, but besides the price, would there have been any drawbacks of using the TSK3 kit?

 

I dunno, to me, it just seems like for the cost of a complete clutch job that will likely last another 100,000 miles, and everything that is involved in replacing a throwout bearing, just seems like good insurance by throwing in a TSK3 kit.

The TSK3 kit actually uses a weaker bearing which causes it to wear out sooner... or so I've heard. I'm not sure that's great insurance.

 

Either way, aftermarket clutches typically don't last as long as the OEM clutch and definitely don't last 100k. They hold more torque but wear out sooner.

 

My trans snout wasn't scored or rough at all - sure it showed some marks on it from the throw out bearing sliding on it, but I couldn't feel them with my finger nail. If you've got palpable groves on it or burrs, by all means, use the TSK3. I didn't see a need.

 

I don't agree with the "Just slap it on as insurance whether you need it or not" mentality. You're spending money on parts you potentially don't need which could/usually end up wearing out faster than the parts you aren't using.

Fair enough.

@baconbits, good read and thanks for the write up.

looking at the fx250 myself and out to source one pretty soon since my OEM is slipping on high boost.