HeelAndToe

With 140,000 miles, it's time to replace clutch (and possible a rebuild on gearbox/transmission for bad 2nd and 5th gear synchros). I've held out for several months, while trying to find a suitable aftermarket replacement clutch setup. I know I want to get rid of the dual mass flywheel. So far, the only options for an aftermarket solid flywheel seem to be Exedy, Spec, ClutchMasters and Fidanza. The Exedy is only available in Austrailia. As far as clutch, I'd need to go with a sprung unit, and again, this seems to be limited to Exedy,Spec and ClutchMasters. From what I've read on the forum, the common setup seems to be Fidanza with Spec 2 clutch...but the reviews seem to be mixed. Mostly complaints about noises and rattles, etc. I found one review with the Exedy clutch and flywheel kit. But that's about it...The ClutchMasters seems to be the newcomer.

I'm looking for at least some performance, but I want to retain the driveability. But I also don't want to have to deal with rattles and such a few weeks after the install. (I have plenty of rackets and clutch noises in my road race unsprung clutch car).

So, can anyone give a good solid recommendation for a flywheel clutch setup for the IS that will free up some of the HP lost to the DMF, but not rattle and annoy during the daily commute? Has anyone tried the full ClutchMasters setup?

HeelAndToe

Must be even more limited than I thought :-(

Ultra4

Toyota is one of the least creative auto companies on the planet. All of their clutch stuff generally comes in 2 sizes, car or truck, with those two sometimes being broken down into big or small subcategories.

The only thing "special" about the IS250's AY6/RA62 is the flywheel, and I hiiiighly suspect it's the exact same thickness as either a "big car" or "small truck" that they've offered for 40+ years. When I finally get greenlit for the clutch on my wife's 250, I'll be buying the SL25A and finding out.

Disc is nothing special, if you go to a stealership, they'll toss a 31250-33032 bandaid clutch in there, which has rubber pucks instead of springs, charge you a couple grand, and you'll still hate it. Disc specs are 9.25" diameter, 21 spline 1.125" shaft. IIRC, it's the same as Chevy, which makes sense, given the AR5/R154 swappability, I'd assume Chevy AY6 parts are the same as Toy RA62, too.

Pretty sure clutch slave and master are both 5/8" diameter, which is the only oddball thing about the setup, aside from how it's plumbed.

Ultra4

This is the current clutch you'll get from a stealer. If anyone wants, I can set up better pics so you can see the dimensions and count the splines for yourself.

It's just regular ol' GM junk at 10x the price.

Jeff Lange

iTrader: (1)

Toyota sizes their clutches and pressure plates to match the application, either by diameter differences and/or spring strength, similar to most other manufacturers. For cars, most of their clutches are typically one of the following sizes: 180, 190, 200, 212, 224, 230, 236, 240, or 250 mm, usually with a 19- or 21-spline shaft but there are others. For trucks, sizes are usually one of the following: 212, 224, 236, 250, 255, 260, 270, 275, or 300 mm, usually with a 14- or 21-spline shaft but there are others. Vans and other utility vehicles are usually mixed somewhere between them.

The clutch on the RA62 is somewhat unique, but also somewhat common to other Toyota setups. It is a pull-type clutch which is similar to the R154 and V160/161, in fact the release bearing is the same as the V16x and the pressure plate is the almost the same design as the 2JZ-GE V161 (like the GTE's pressure plate, but without the cooling fins and with a lighter clamping force). The flywheel is unfortunately quite unique in the IS250, even though other vehicles also use the AY6 and Toyota has used dual mass flywheels in several applications. Even between the IS200d/IS220d and the IS250 which all use the AY6, the flywheel is noticeably different for the IS250. The two biggest things that are unique compared to other Toyotas is the large step between the pressure plate mounting surface and the friction surface (approximately -8 mm from memory), and the actual overall thickness of the flywheel. The only other Toyota off the top of my head that used a similar step was the 4A-GZE and its 224/230 mm flywheel, though I suspect there may be another couple out there.

Other GR/AY6 setups use a push-type clutch with a larger 275 mm disc. The crankshaft bolt pattern is different between the 1GR and 2/3/4GR. The bellhousing on the RA60/61 is also larger to accommodate the larger diameter (but much thinner) flywheel.

This is one spot where the GM 3.6L setup is somewhat similar to the Toyota setup, the GM flywheel has a similar step, but is much thinner overall.

While the size and material of the original disc is nothing special, the factory disc is unsprung (as the flywheel dampens vibrations) and not used in any other application. If you go to a dealership, they will sell you a 31250-53050, which looks like this:



The 31250-33032 is only used if they are performing TSIB L-SB-0059-11 (USA) or TSB L-TCI-2960 (Canada), which also includes replacing the transmission with updated part 33030-53370 to get rid of the abnormal noise on some vehicles when releasing the clutch. Otherwise they will just be putting the original unsprung 31250-53050 back in there. Either way, the goal was to get rid of the abnormal noise, not affect the way the car drives, hence the car will drive about the same (I've had both the original transmission with the unsprung disc, as well as the updated transmission with the rubber-damped disc.)

The GM AR5/R154 is a bit easier than the GM AY6/RA62 because the bellhousing is not integral to the transmission case, and so a Toyota bellhousing can easily be swapped onto the GM transmission. That said, you're still forced to use a non-Toyota friction disc, as the input shaft splines are different between the GM transmission and the Toyota transmission. This is also the case for the AY6, the GM version uses a 23-spline input shaft in place of the Toyota 21-spline. Additionally, it is a push-type clutch and uses a pilot bearing with an integrated slave cylinder in place of the pull-type clutch and release-fork with external slave cylinder that Toyota uses on the RA62. In short, don't look to GM for any compatible clutch components for the IS250.

The master cylinder is a 3/4" diameter, and the slave cylinder is a 15/16", which isn't a super common size for Toyota (though they have used those same sizes on other applications like the TRN2## Tacoma).

As I said earlier, the GM AY6 setup uses a very different setup which is a 255 mm 23-spline disc in place of the 236 mm 21-spline disc of the IS250.

It's interesting because GM actually doesn't sell just the clutch disc by itself, you have to get the pressure plate and clutch disc as a kit, which lists for $389.43 (2010-2012 Cadillac CTS and 2010-2015 Camaro, Part No. 19353433). Toyota lists the clutch disc for $86.18 for the original unsprung disc and $116.19 for the rubber damped disc. If you include the pressure plate (Toyota Part No. 31210-53032, lists for $354.74) it's a bit more expensive than GM by $51.49. I'm sure your 10x estimate was a bit of hyperbole, but it's really only 13% more expensive for the Lexus clutch and pressure plate than for the GM clutch and pressure plate (which won't fit anyway).

As for the original poster's question, there are a few options out there for different setups for the IS250 6MT, but not as many as other cars, that's for sure. The only other alternative options I really have to add other than what you've already listed would be the PGEAR FW1224005 flywheel (unfortunately out of stock and requires a minimum qty of 5 to run them due to lack of demand) and possibly going with a larger sprung disc. The flywheel and pressure plate can handle a larger disc up to about 250 mm.

I am running a 250 mm Aisin NVR sprung disc on a PGEAR chromoly flywheel using a higher capacity SPEC pressure plate with no clutch accumulator:





(One other clutch/flywheel setup exists and that is the setup from the GRMN Mark X, which is a stronger version designed to handle the 3.5L's higher output, but it's still a dual mass setup, and very expensive, so probably not worth considering.)

Jeff

Ultra4

This is more information in one post than I've been able to gather in 6+ years of fairly religious searching. Thanks a zillion.

Ultra4

Wouldn't happen to know the starter ring diameter and tooth count of our setup and a VZ Taco, would ya?

I'm thinking the VZ/MZ setup would work with a new collar making up the difference between the throwout fork and the throwout bearing itself. That collar wouldn't need to be anything special, you could turn it yourself from aluminum tube stock.

Jeff Lange

iTrader: (1)

Not a problem, glad to offer some information. There aren't a lot of people out there doing anything too ambitious with the 4GR and/or the RA62/3, so information is a lot more scarce than for other platforms. Plus there just aren't a ton of 6MT cars around, which also makes things a bit worse.

Jeff

Jeff Lange

iTrader: (1)

Just saw this.

The 4GR and VZ both use a 120-tooth 305 mm 20-degree pressure angle ring gear. This is a pretty common ring gear size for Toyota.

Jeff

Ultra4

I'm definitely going to be trying that route, then; Taco flywheel/clutch setups are dirt cheap. From the various clutch threads on here, I gather that the throwout bearing is retained to the hub via c-clips, which is really the only difficulty setting in my idea of fabbing one's own bearing-to-fork hub...once you get the c-clip groove dimensions correct, the rest is just details. Might need to integrate a SS washer between the fork and hub, to act as a friction face and avoid galling the hub up.

Edit: simpler route: remove clutch fork pivot mount, use those two bolt holes to locate a baseplate for a hydraulic throwout. Might need to reach across the other side of the pivot mounts and pick up a bellhousing/case bolt or two to stiffen it up,

Jeff Lange

iTrader: (1)

If you're going to try to switch to a push-type clutch setup, a hydraulic throw out bearing is pretty much the way to go for sure. There is a case bolt directly opposite the fork pivot mount bolts that could be used to retain things. If you were going in that direction, my suggestion would be to get an automatic flexplate to use for the ring gear, then have a spacer made to bolt on whatever flywheel you want to use. That's the only nice thing about the stock flywheel being so thick: there's a lot of room in there to do various things.



My original plan before ordering the PGEAR flywheel was to make my own flywheel and use a V160 2JZ-GTE pressure plate. Doing that opens up a lot of options for performance clutch pieces for years to come. I doubt SPEC will continue making pressure plates in the coming years, Lexus has already discontinued the F-Sport pressure plate, and I need the added clamping force to handle the increased power from the 2GR.

I modeled the PGEAR flywheel using limited dimension information I got from PGEAR and measuring things, I will likely design a new flywheel setup for my car at some point. Either using the flexplate idea (which is actually what SARD did for their 6MT kits) with an aluminum spacer and then a steel flywheel or just doing an entire flywheel (though likely with a separate ring gear, as they're cheap to buy separately).



Jeff

Ultra4

Any reasons you're not moving to one of the higher-output pull-type pressure plates from the Supra or Skyline world? I've seen images of both with an appropriate bolt/locator pin layout. Dunno how proud of them they are, but I bet it's awful.

My current plan is to go with the fly/clutch/PP from a VZ taco, getting a 3x8x.5 or so piece of aluminum stock to drill/shape/trim to fit as a backplate for a HTB, and setting my clearance distance with 1-3/16"ID thick-wall tube trimmed to fit. Will want to get a HTB with mounting ears and run studs from the backplate, or secure it with a collar of some type.

Jeff Lange

iTrader: (1)

That is what my current plan is. The plan is to use a V160 pressure plate with a custom flywheel, which I have designed, but the PGEAR was significantly cheaper, so I went with that for now. When I need a new clutch (wear or additional power), I will likely have the new flywheel made. It will be lighter than my current setup as well.

Basically what I was thinking, though I do question if all that effort will be worth it over getting an off-the-shelf solution. I suppose it depends how much you feel like taking on the project, sometimes it can be enjoyable to do something even if there are other options available.

Jeff

Ultra4

I mean, in my mind, aside from the 3-6 hours of fidgeting with holes and angles on the bar stock and getting everything dimensioned correctly, this clutch solution is as "off the shelf" as the platform can get. I can order everything I need from here, and everything combined is a better overall package, available for less, than what I'd get if I paid somebody else to touch my vehicle. The parts are WAY more readily available, and there are significantly more performance options compatible with a hydraulic throwout bearing.

The SL25A is the only legit aftermarket flywheel option, IMO, and if I can get this whole setup running more traditionally for the price of one, then I've beaten the system. And even if I blow the budget, multi-disc clutches are an option without needing a sacrificial child or enough income to not be dealing with this turd engine/trans. My favorite 2IS dream build so far has been a 4.7l Powertech with the '08+ dual-sparkplug heads and a lot of work, backed by the TR6060 from--IIRC--an '09 Challenger...if I had V160/V161 aftermarket part money, that's what I'd be building, instead.

HeelAndToe

First off, thank you so much for all the info. This is def a great deal of info, on par to what I'm looking for. I admit to having kinda given up on getting any response, so I haven't checked for a while. I'm glad someone resurrected with such detailed info (which I'm still absorbing). I've done several clutches in the past (Matrix 2ZZ, MR2 AGE race car car, Accord), but this will be my for foray into a RWD Toyota setup. Ideally, I'd like to keep the car as close to stock as possible, but without the DMF...I'm also curious about removing the accumulator..I might need to read up some more on this...I'll probably be removing the tranny myself to save cost (I'll send out the tranny to have it rebuilt), so I'm gathering as much info as I can to limit downtime. Again, thank you for all the good info.