With the 3/4" Master, the sky's the limit for what slaves you can run after you delete the accumulator...3/4" is your basic muscle car size, I have both pull and push cylinders in 3/4, just laying around, but nothing has the 2-bottom-hole setup like the RA62 wants. 3/4's also the same size just about every hydraulic throwout bearing wants. I'm half tempted to use an F-body leak-o-matic just out of principle.

Everything done to our 250 since 2013 has been solely by me. Like, I haven't had a light holder, or a gopher, or even someone hanging around ready to dial 911 for when I ugga-dugga the thing off the jackstands onto myself. The most infuriating thing I've had to adapt to is none of my floor jacks fitting under the jackpads, so getting the thing in the air is like a 10-step process that involves lots of scrap wood, a pair of ramps, a little bit of burnt clutch, and a really puckered butthole.

At about 110k miles (and a couple thousand miles of hate-driving it after my sob story about losing my late F-I-L's perfect '07 6MT 'vette) I figured I'd abused that wretched RA62 enough to warrant putting real fluids and PMCS into it. The fluid that came out was crystal clear, like it just came out of the bottle...only one barely noticeable chip stuck to my finger after trying to find any grime inside the case itself. The Royal Purple that's been in there for ~20k is still perfectly purple. My Toyota master tech buddy says that's fairly typical of Aisin RWD boxes in Toyotas and that he'd only ever done factory reworks on Aisin RWD transmissions, never seen one broken beyond clutch abuse. So I'd say, at least anecdotally, that you should be fine never having to crack the case of that transmission open. I think just a flywheel, clutch, PP, and a new hydraulic setup (my pref being HTB, but both push and pull cylinders can be used, if you work with the geometry), is all you need to do.

Just gotta be smarter than the task at hand.

 

Unfortunately, I think my case will need to be cracked. 2nd gear synchro is all but gone, and 5th is on it's way out. I bought the car with 127K (USA), and even thought I researched and found that it was serviced by the dealer until right before I bought it, I am not sure how it was driven prior. I baby the car (I have an MR2 track car I get to flog as the need arises). The only reason I haven't pulled the trigger on doing the clutch at this point, is that I'm trying to find a good shop to do the synchos. I'd love to find a good used '10+ MT, but I'm sure that's all but impossible!.

 

So at the moment, the biggest roadblock for me is PP locating dowels on flywheels. Seems to me that the setups that have the the 3 dowels equidistant from the mounting bolt holes (like you see on Jeff's flywheel above) are the R154/V160/V161/RA62 style of pressure plates that need the throwout bearing pulled away from the flywheel to disengage the friction surfaces. The plates that have the 3 locating pins directly next to the bolt holes need the throwout pushed in toward the flywheel, like has been more or less internationally standardized since the 1930's.

If true, then I should be able to run a 3SGTE fly (pins next to bolts) and clutch setup with an adapted HTB, no?

 

Is there just a flywheel I can buy that's oem spec?? I recently replaced the clutch on my wife's 08 250 6MT the transmission shop was able to re surface the flywheel but, a brand new one at the stealership is ridiculous for the price they are asking.

 

Yikes, that's a no-go on a dual-mass. I know the OEM DMF is available, but I've never seen a reasonable price. $2k+ is usually what I see it going for.

 

What is a good alternate?? Is a single mass a good option??? Because I was reading mixed reviews on swapping out the OEM Dual Mass for a Single and these cars were not built to run a single mass flywheel and it will cause problems in the future. Thanks Lexus for building a crappy manual transmission.

 

Eh, it's not so much a crappy transmission as crappy implementation of the clutch system combined with the outer edge of usable gear ratios. If I were, right this very second, in the absolute need for a new clutch setup to run, I'd do a SPEC SL25A with an ACT T015X pressure plate and an ACT pn# 3000607

If I'm wrong here, I beg you to stop our friend from travelling down the wrong road...

 

Also, a Y-38 differential--with the 4.1:1 ratio (opposed to the ~3.73:1 open) Torsen--will make your clutch soooo much happier.

Seriously, if you have a factory clutch pedal and you're fine with the stock differential ratio, you need to never own another manual transmission.

 

We use a clutchmasters clutch with Fidanza aluminum flywheel. Clutch uses a dual sided disk, organic one side and segmented other side. Clutch has been holding 360hp for a while now, and tranny has about 155,000 on it.

I keep meaning to delete the clutch delay valve, will do it soon..,

Rafi

 

Rafi, we exchanged emails a few months ago and you mentioned you were using ClutchMasters. I had been meaning to reply to that email to see how it was holding up. I'm glad you chimed in.

 

Since this is the thread google likes the most, I'm posting this info here, for those looking for higher-horsepower holding capacity. Application for the T014X is Mk4 Supra 6sp, with the pull-style (larger-diameter) throwout bearing. I may need to order a donut to push the friction surface out the 7.5mm needed to get it flush with the mounting hardware like the Mk4 Supra application has, but that's just a matter of transfer-drilling holes and maybe getting longer hardware.

 

The release bearing for the Supra and IS250 are the same part number and size. The only real issue is the friction surface height difference.

Jeff

 

Yeah, finally talked to some folks and got my mock'n'measure all cleaned up late last night and slept on it.

Mk4 Supra flywheels typically have a .020 bump up (toward the trans/rear of vehicle) from the mounting hardware. The SL25A friction surface is 7.5mm on the nose sunken into the fly. Typical clutch disk thickness is 7.5mm. Additionally, the hardware attaching the friction surface to the SL25A is 100-degree countersunk #10-32tpi hardware. Friction surface OD is 10-3/8", inner hole is 6".

Therefore, a 5/16" thick ring with a buncha transfer-drilled .1935" holes will need to be made. 7.5mm=.2953"; 5/16=.3125"; .3125"-.2953"=.0172. Close enough to .020" proud for me.

 

does anyone know if these parts are compatible for a 2008 RWD 6mt I don’t wanna have to deal with finding someone to machine my DMF and want to have a little bit more power in this underpowered and over weight car hope someone can help

 

The SL25A, ACT disc and LUK pressure plate are working well behind the 3GR-FSE. A bit grabbier than I want, but that's the price of my laziness for not deleting the delay valve yet.

Edit: just saw the parts you hid in the title. The disc you mention is unsprung, which is generally regarded as a bad idea with the single-mass setup. 1.125", 21 spline, max OD just about 10"...I'm not sure if a 10" disc would work or not. Lots of options to choose from, from basic organic to ceramic/kevlar multidisc hybrid.

Edit2: Aisin CKT-022 appears to be sprung, organic, and relatively affordable

Edit3 since you complain of it being underpowered, I suggest a Y38 or Y58 differential swap, so you're actually applying power to both rear wheels, instead of skateboarding off all the rubber they put in the suspension. That iconic IS250 6MT "na-na-na-na-naaaaaa" start goes away with the new diff.