Replacement Clutch Recommendation for an EJ25 ?

[dirty_mech]

In December 2019 I replaced my 2000 Legacy wagon's clutch with the M-PACT 15004 clutch kit from RockAuto.  The old one was slipping hard and had worn the disc down to the metal rivets.  On the new clutch, I believe I recently detected a tiny amount of slippage during hard acceleration in 1st or second gear, and suspect I'll need to replace the friction disc again later this year, which means I'll have gotten about 2 years out of it. 

It's not surprising, and I don't necessarily blame the quality of the part other than having basic performance.  My Legacy carries a heavy load of tools and parts at all times, roughly 400-500 lbs.  This has led to me burning the disc at least a dozen times since replacing it, usually when reversing uphill after parallel parking on crowded streets.  The Legacy just can't take it when carrying a heavy load.  I've since learned to be wary of neighborhoods built on steep hills.  I never park my Legacy anywhere that would force me to reverse up anything more than a very mild incline so I don't burn the clutch.  I also have a somewhat aggressive driving style in urban city streets, and sometimes need to rely on hard acceleration to get me past obstacles in dynamic traffic situations. 

I need a recommendation for a strong replacement clutch disc that will put up with the heavy load I regularly carry and hard acceleration in lower gears. I don't suspect that I need to replace any of the other parts since they were replaced in the past 2 years, just the disc, although I'm intrigued by some of the clutch kits which include a replacement flywheel.  The standard M-PACT friction disc would probably be fine for a person who drives normally in car that isn't loaded down, but I'd rather avoid replacing my clutch disc every 2 years.  I'd like one that could last me a good 5 years if possible.

The current OEM dealership part is Subaru part # 30100AA851, going for $180 dollars.  Based on what I saw in the forum search for clutch info, I'm guessing this one is produced for Subaru by Exedy, It appears identical to the Exedy FD501D Stage 1 organic clutch disc, currently out of stock at RockAuto but on Amazon for $135. 

Another option is the EXEDY FJD016CB Stage 2 cerametallic clutch disc,  ranging from about $350 online.  Steep but I'd pay it if it performed like a $350 clutch disc.

On Amazon I see six-puck racing clutches by ClutchXperts advertised as Stage 4 and Stage 5 clutch discs made of copper-ceramic Miba.  They are only $55 and $62 respectively, which makes them very attractive, but I don't see a single review for any of them. 

Anyone have an opinion on these options?  Any better options I missed?  I might just preemptively throw a new clutch disc in next month if the promise of improved performance is tempting enough.  The pics are of the old clutch, which I mounted to the wall outside after replacing it last. 
 

 

[el_freddo]

From what I’ve heard about the six puck racing clutches is there’s very little slip. The bite zone is very quickly the clamped zone and you’re off. Not good for a daily and a smooth ride, unless you’re full raceboy all the time. 

Any organic clutch disc should do the job well. A lot comes down to clamp force of the pressure plate, this can add extra stress to other components as the pedal becomes heavier to operate - another thing to consider when upgrading the clutch. 

I think you’ve already identified that your clutch slipping habits need to change, and that you’ve already changed some of your choices in the parking department. 

I’m no clutch guru, do some research, read the manufacturer’s website for info. Others here will chime in. For me I’d replace the disc, especially if it’s just my time working on the vehicle and not paying someone else. 

Cheers 

Bennie

[dirty_mech]

6 minutes ago, el_freddo said:

Not good for a daily and a smooth ride, unless you’re full raceboy all the time.

Not all the time, just 1/3 or so.  I'm not saying I drive my Legacy like Miles Fox used to drive his trashwagons, but sometimes I might.     I do try to avoid jumps nowadays though.  It's hell on the suspension when you do it with 500 lbs of crap in the back.  I've already had to replace a blown shock which was only a couple years old and several heavily worn control arm bushings, which is rough work I don't want to have to repeat.  About to throw some Outback shocks on it now so my exhaust stops scraping inclined driveways.

I've driven a number of EJ22 and EJ25 wagons and I'm just not impressed with the OEM clutch power.  With the OEM EJ22 disc it's a known issue, but I'm not very impressed with any improvement they might have made on the EJ25.  Too much slippage; I'd rather have the engine stall than get hit by that nasty burning asbestos smell of organic clutch ever again.  It's probably just fine if you aren't hauling a lot of weight, but I like to use the back of my Wagon like it's a truck bed, and the steep hill neighborhood are likely to be on my itinerary for the foreseeable future.  I need a clutch that will grip solidly and keep up with the engine when I need to crank out those high RPMs under heavy load to get the car moving on hills.  I know the engine has more power; the weak link is the clutch.

Duly noted on the 6-puck clutches.  I've also read that before on this forum.  I'm tempted to try it to see if I like the extra clutch power, but I'm worried the car will jump like a jackrabbit when first moving and fight the engine too much when shifting if it isn't done perfectly, making the ride rough as you describe.  I'm leaning towards a Stage 2 or higher clutch disc with a non-organic material like carbon fiber or ceramic, but which retains the full radius shape of the OEM disc.

The EXEDY FJD016CB Stage 2 cerametallic clutch disc mentioned in my OP would be a good example, but I don't want to drop $350+ on a part unless it has rave reviews, and I don't see any on the Amazon page for it.  I do see on Amazon a similar ceramic disc in a clutch kit by Southeast Clutch, # 15-004, for about $110.  The handful of reviews all seem positive and more than one mentions that the clutch pedal feels the same as stock.

If anyone has any experience with non-puck, non-organic clutch discs, I'd be interested to hear about it. 

 

[idosubaru]

1 hour ago, dirty_mech said:

like Miles Fox used to drive his trashwagons, but sometimes I might.     
I've driven a number of EJ22 and EJ25 wagons and I'm just not impressed with the OEM clutch power.  
 

hahaaahahahaa!!!

Tolerate me for 20 seconds. sounds like you’re pushing the OEM limits but to be clear:

have you driven an OEM clutch brand new with brand new or resurfaced flywheel? Would that make a difference?

probably won’t matter - a new one would be a used one shortly with that kind of work out. But if you’re only experience is 14 year old craigslist specials with unknown clutches and flywheels...?

Can you use any of the turbo clutches?  They’re throwing significant power and use at them and have figured out clutch options. EJ22T? EJ20T?  EJ25T? I guess the issue is cost - OEM might be better but $$$.  I’d probably pay it - clutches are about the worst job to cut costs on or take chances of redoing.  Redoing a clutch is a mind numbing asinine waste of my time. I have turned down people asking me to install auto parts store clutches.  I’m not risking doing that again. I do free labor only - I refuse payment - but I’m not going to waste my time or risk feeling like I need to do it again or be blamed for a failure....which I’ve seen on new aftermarket  clutches. 

Edited April 25, 2021 by idosubaru

[el_freddo]

Your clutch is typically under most load when engine revs are low and the throttle is WOT. Once the engine spins up a bit the clamping force on the clutch isn’t required to be as high due to its load being less. 

Think about when a worn clutch will slip the most - low revs and high load. A really bad clutch will slip at high revs, and would need to be babied to get there generally. 

If you’re pulling high revs and slipping the clutch from not fully engaging the clutch then there’s your issue with your clutch slip (that’s how it read to me). When using the clutch in this fashion I find it best to keep revs as low as possible, have just enough slip for the vehicle to move the way I want it to without the engine stalling or clanking around. 

High revs and slipping the clutch = lots of heat from the friction of slipping the clutch = ending up with smoking the clutch. 

You will no doubt have fine cracks in the flywheel friction surface and possibly on the pressure plate if it’s really bad. 

As Ido suggested, a turbo clutch could be the go, but you’ll need a turbo gearbox (different ratios, potentially another issue) to facilitate the pull style clutch setup. 

If you’re swapping gear bags you could look into importing a dual range gearbox. The low range will be 1.19:1 but it’s better than 1:1!

Cheers 

Bennie

[1 Lucky Texan]

when it's clutch time on my WRX I've been thinking about a lighter clutch, but not super light, maybe just the next step down from stock. Evidently it can sometimes be tricky driving?

[dirty_mech]

17 hours ago, idosubaru said:

have you driven an OEM clutch brand new with brand new or resurfaced flywheel? Would that make a difference?

you’re only experience is 14 year old craigslist specials with unknown clutches and flywheels...?

Can you use any of the turbo clutches?  They’re throwing significant power and use at them and have figured out clutch options. EJ22T? EJ20T?  EJ25T? I guess the issue is cost - OEM might be better but $$$.  I’d probably pay it - clutches are about the worst job to cut costs on or take chances of redoing.  Redoing a clutch is a mind numbing asinine waste of my time. I have turned down people asking me to install auto parts store clutches.  I’m not risking doing that again. I do free labor only - I refuse payment - but I’m not going to waste my time or risk feeling like I need to do it again or be blamed for a failure....which I’ve seen on new aftermarket  clutches. 

Would it be that big a difference between stock and aftermarket organic clutches? Freddo seems pretty convinced that "any organic clutch" should perform well.  I haven't had experience with poor quality clutch parts, but I am pretty cautious about buying anything that doesn't seem of verifiable and reasonable quality.  I agree that you should definitely not go cheap on parts, but you have to make sure the cost corresponds to quality.  I'm not necessarily going to praise stock parts and avoid aftermarket unless there's a known issue with aftermarket parts being inferior to stock.  They often are like with head gaskets, but the dealer oil filter for example is just a Fram filter that's been repainted with the Subaru logo, and I won't be putting either on my engine anytime soon. As far as the clutch goes, I'd be interested to hear if you think getting a stock Exedy one would make a big difference.

Definitely a lot of Craigslist specials in my past but I've put new clutches in on at least three of them.  Never had problems until I had to start using my wagon like it's a service truck.  I'm sure it would be fine without the extra weight, but other factors are combining to give me trouble.  Not only do I have the heavy load in the car at all times, but there's a lot of neighborhoods on steep hills where I drive.  

I also have to deal with 5% of people on the road drive like they're raging on meth and another 5% drive like they're stoned of their minds, people who feel entitled to block lanes of traffic anytime they like, and the occasional person who does something so moronic it defies categorization.  It all adds up to a lot of braking and acceleration and shifting, all with that heavy load in the car, which isn't doing the clutch any more favors than those steep hills. I'm sure the OEM clutch would operate well under normal conditions, but I'm just not operating under normal conditions.  I'd like to find something that can last longer, or provide better performance, or ideally both.  I may be wrong but I suspect there's a better option out there, and I'm willing to take the chance that I'm wrong to find out.  The turbo clutch sounds intriguing but freddo indicates I would need a whole different gearbox.  I'm interested in getting more clutch power but I'm not not willing to go so far as to replace my transmission.
 

17 hours ago, el_freddo said:

Your clutch is typically under most load when engine revs are low and the throttle is WOT. Once the engine spins up a bit the clamping force on the clutch isn’t required to be as high due to its load being less. 

Think about when a worn clutch will slip the most - low revs and high load. A really bad clutch will slip at high revs, and would need to be babied to get there generally. 

If you’re pulling high revs and slipping the clutch from not fully engaging the clutch then there’s your issue with your clutch slip (that’s how it read to me). When using the clutch in this fashion I find it best to keep revs as low as possible, have just enough slip for the vehicle to move the way I want it to without the engine stalling or clanking around. 

High revs and slipping the clutch = lots of heat from the friction of slipping the clutch = ending up with smoking the clutch. 

You will no doubt have fine cracks in the flywheel friction surface and possibly on the pressure plate if it’s really bad.

 

It's possible I have a really bad clutch, or it's just all the extra engine load.  I feel the high revs are sometimes needed to prevent the engine from conking out, which I will do at lower revs sometimes, so maybe the issue really is the engine power being too low and not the clutch.  Or maybe I'm just getting the engine revs up too high when I try to avoid killing the engine. Hard to say.  I certainly see how that type of slippage could generate too much heat and damage the flywheel.  That's one thing that concerns me about possibly using a ceramic clutch, as it will surely put more wear on the flywheel just as ceramic brakes do on rotors.

[idosubaru]

I’m inexperienced with performance clutches and high use applications for manuals trans so I can’t recommend anything.  

im surprised turbo clutches are that different. If you but a turbo clutch pressure plate and flywheel....it doesn’t fit?

[dirty_mech]

I'm just going off what freddo said.  I'm as curious as you are.  I looked on Amazon and the turbo clutches appear to look similar, although the flywheel is different.  I don't know what a pull-style clutch setup is all about; does that mean the clutch fork pulls the bearing away instead of pushing it forward?  If something like that was the case then it would make sense that the turbo gearbox is configured differently. 

[idosubaru]

As you knew already, looks like they’re different.  I’ve always just ordered a stock clutch, never paid attention to what’s interchangeable on new gen.

 

[el_freddo]

Yeah the phase 1 turbo gearbox and I believe the phase 2 gearboxes have different front case halves to facilitate the turbo clutch. On these the clutch fork pivots on a pin built into the gearbox case and the throw out bearing clips into the fork to pull  on the pressure plate. 

To remove it you first pull the pin out and from memory the fork comes out with the engine and then it’s unclipped. 

You can get upgraded pressure plates made to your specs or to what the specialist thinks you need from your description of vehicle use. 

I reckon if you’re moving those sorts of loads on inclines you need a dual range box, an auto or a bigger vehicle... 

Cheers 

Bennie

[Numbchux]

12 hours ago, dirty_mech said:

I don't know what a pull-style clutch setup is all about; does that mean the clutch fork pulls the bearing away instead of pushing it forward?

This is exactly correct. Turbo 5-speed EJs up to 2005 (certainly true in WRXs. FXT/LGT/OBXT might have switched in a different year) are pull-style. These use a different flywheel and pressure plate, but the disc itself is the same.

 

The WRX switched back to a push-style in 2006, so stock replacement clutches for those are popular options for NA-T builds.

 

I would highly recommend upgrading your pressure plate as well, the extra clamping force will help with disc wear as well. I can't imagine pulling the engine to replace clutch components and put the same pressure plate back in (and I've got almost 30k miles on a $50 eBay clutch kit in my '00).

[dirty_mech]

Hey Bennie, thanks for the explanation on how the pull-clutch works.  Those turbos sound complicated but I bet they are fun to drive. 

On 4/26/2021 at 12:48 AM, el_freddo said:

I reckon if you’re moving those sorts of loads on inclines you need a dual range box, an auto or a bigger vehicle...

It's entirely possibly I'm just a jackass with an overloaded, underpowered vehicle driving around on too many inclines.  But a man can dream, can't he!? 

On 4/26/2021 at 7:27 AM, Numbchux said:

This is exactly correct. Turbo 5-speed EJs up to 2005 (certainly true in WRXs. FXT/LGT/OBXT might have switched in a different year) are pull-style. These use a different flywheel and pressure plate, but the disc itself is the same.

The WRX switched back to a push-style in 2006, so stock replacement clutches for those are popular options for NA-T builds.

I would highly recommend upgrading your pressure plate as well, the extra clamping force will help with disc wear as well. I can't imagine pulling the engine to replace clutch components and put the same pressure plate back in (and I've got almost 30k miles on a $50 eBay clutch kit in my '00).

I had never heard of NA-T (naturally aspirated to turbo) conversions on Subarus before, but I see that's a popular thing.  Very interesting, thanks for the heads up!  So would it be possible to use a 2006 WRX turbo clutch on my 2000 EJ251 NA engine?  Would I need the turbo pressure plate and flywheel as well, or would the disc work with the stock non-turbo EJ25 components?

Thanks for the advice on the pressure plate.  In that case, I will keep an eye out for kits rather than just the disc.  30k is probably what will be on this clutch when I do replace it around New Years or whenever it gives out.  It's actually still in pretty good working condition and I haven't felt any slippage for days, but I don't want to risk unexpected down time again.  This past year has been like a college class in auto repair with all the parts that have gone bad on my poor Legacy.

[dirty_mech]

So after a lot of research and consideration, I found and went with the EXEDY 15801 Stage 1 racing clutch kit off RockAuto.  It's a step up from the EXEDY KSB04 OEM Replacement Clutch Kit.  Still an organic clutch disc but higher quality materials for better performance.

The one issue with this kit is it only comes with a standard bearing.  My previous M-PACT clutch kit came with a standard throwout bearing and an oversize bearing with a repair sleeve to deal with the common transmission quill damage issue.  I did notice some wear marks on the aluminum quill, which is why I used the oversize bearing and repair sleeve 18 months ago when I last did this job.  I also noticed that the original throwout bearing retaining wire had become detached on one side; not sure if that's caused by quill wear on just something that can happen on an old Subie clutch. 

So here is my final question on this subject for you guys; do you think I should use the old oversize throwout bearing with repair sleeve, or use the new bearing without the repair sleeve?  The wear marks on the spindle were noticeable but not deep enough to be alarming.  I actually had to consider whether or not to use the standard size bearing when I was last looking at it.  I'm not super interested in buying a new oversize bearing, in part because my clutch has actually started to slip consistently during hard acceleration.  I expect it to fail completely sometime within the next week or two, so I want to get this job done ASAP.  My options are reuse an 18 month old bearing with about 24k miles on it, or use a new bearing without the repair sleeve on a mildly worn quill.  What would you guys choose?

Edited May 17, 2021 by dirty_mech

[idosubaru]

4 hours ago, dirty_mech said:

 

So here is my final question on this subject for you guys; do you think I should use the old oversize throwout bearing with repair sleeve, or use the new bearing without the repair sleeve?  The wear marks on the spindle were noticeable but not deep enough to be alarming.  I actually had to consider whether or not to use the standard size bearing when I was last looking at it.  I'm not super interested in buying a new oversize bearing, in part because my clutch has actually started to slip consistently during hard acceleration.  I expect it to fail completely sometime within the next week or two, so I want to get this job done ASAP.  My options are reuse an 18 month old bearing with about 24k miles on it, or use a new bearing without the repair sleeve on a mildly worn quill.  What would you guys choose?

I'd look and see if the FSM has measurements that help make that decision. 

All that extra weight is killer.  Like you said they're not geared for all that weight - I've had some heavy trailers that I could tow but couldn't back up at all up a grade. 

[el_freddo]

An 18 month old TOB should be fine to reuse. 
 
Cheers 

Bennie