All these widely varying opinions are why it's a scary thing to jump into.

 

Don't get me wrong, I love my R154. I had a rare legit original W58 SC300 and I defiled it and crammed in the R154 slambox. If you have goals above 300hp, the W58 is a bad idea. You'll need an R154 of some variety or flavor.

 

I'm happy at stock-ish power. I prefer lighter weight over more power, so the W58 is plenty capable. I'm just not thrilled with the idea of a used and potentially abused high wear item from two to three decades ago.

 

Based on this I need to look for (ab?)used W58 for about 200 and then spend 800 to service it up. Any price higher than that would tilt me toward a new one for about 2000.

Salim

 

Salim, if you are not going after boost (and you said you are not) then a good 1992-94 SC300 W58, 1995-97 SC300 Tripod W58 or 1993.5-97 Supra Tripod W58 will suit your needs just fine.

t2d2, since you've mentioned you're also not looking to get into boost I'd suggest the same.

Find a steel plate SC/MKIV W58 of any type in good shape (though a tripod style is the newest type) and you should be fine. If any rebuild is necessary it will be about $500 but then it's done.

I had to dash earlier after my last previous post. Ali, regarding what you said:

I COMPLETELY agree even though I do not have a firsthand impression of an auto SC300 or SC400. I'm very fond of the 1995-97 and 1998-00 LS400 with its automatic and overall feel. That's a near perfect car in stock form.

However once I drove an SC300 factory manual car I knew I'd only want that version. So I bought it Incremental tweaks from stock have brought out more of that sports GT car feel Ali is describing. Any decent manual gearbox in an SC is worth it.

^^ I stand by what I said in my last posts but Ali is right: if you can't TEST the R154 you're planning to buy and make sure you're getting a good gearbox it might be a good idea to move on. They may be rarer now but you will see them pop up from time to time.

I also agree that since we've now got all the conversion quirks worked out with the AR5 gearbox I think it's a very good option over the MK3 R154. Shifting will be smoother owing to the all around improved design, though I still stand by my feeling that the MK3 R154 is far from horrible.

However since both gearboxes require some conversion work, why not try the newer one?

For my part the early style R154 fit my own 350whp-400whp power goals and my wish to keep my 5-speed chassis as semi-period-correct OEM as I could. I could forgive some quirks of the original design. Also, when I responded to the ad for my R154 it was at a performance car shop. The gearbox was out of the car and I was able to dry shift the transmission. The original OEM clutch was still on it and the actual MKIII Turbo it came from was in their lot. I could see the car was not really modified much at all and I could verify the chassis mileage on the dash odometer. It was a risk but I figured I had a good chance given those things. When I got the gearbox overhauled they did not see any internal evidence of abuse.

I went with an MKIII box because I knew it would use the trans tunnel and shifter just like my early W58. Also, the ad just popped up and I took a chance on it. Also, at the time the Soarer shift housing parts could still be imported-- now it's custom modification only for the toploader style extension required since those truly are discontinued from Japan inventory.

Conversely, the JZX100 shift housing conversion parts used for the AR5 trans are still available to buy. That's good enough reason for me.

^^^ !

I'm not going to claim the oldest R154 is "butter" smooth Although I still haven't had such a poor experience with mine I will concede that the newer tripod R154's and the AR5 are going to be better since they aren't completely stuck in the 1980's. I daily drive mine and with the OEM 7MGTE clutch it's a pretty normal experience. I plan to go with an organic-face Southbend later on. I'm also using a V3 short shifter.

^^ A Soarer tripod gearbox or AR5 are both great options. If I were building different car I'd probably go with either one.

The things that are not available for the MKIII's any longer are the OEM Soarer extension housing and internal arm (which you would have made custom now) and the OEM replacement 3rd gear/shaft set. That tends to be the one ratio people have been known to break at *really* high horsepower with R154's.

There do exist new replacement aftermarket gearsets from PGS that are stronger but they're $5k alone. You'd have to have a very good reason for that let alone the cash. And that wouldn't solve the rear seal pressure issue at/around 500whp+. I'm not sure about Jack's Transmissions right now but Marlin Crawler, Driftmotion and SpeedForSale still rebuild R154's and all general rebuild/gearing/syncro and upgrade parts are still available.

Still... while the MK3 is a good gearbox for legacy and power the availability of the Soarer/Chaser tripod version and AR5 conversion now outlined for us make a lot of sense for improvements and power.

And the steel plate W58's, especially the tripod W58's, still make the most sense and require the least amount of adapting if all you want is a good, lasting manual gearbox in your SC400

 

1995-97 SC300 Tripod W58
Is my selection.

Next steps:
1) How to find one.
2) Which adapter plate/bell housing and flywheel + clutch
3) Tunnel
4) Drive shaft [heard they can't be serviced]
last item .. convince wife that I should spend time and money on my interest

Salim

 

I think that is a great idea Salim, that is the w58 I have and its never given me a single problem and always shifts nice and crisp (you do have to change the shifter bushing and the cage bushings every 100k or so to keep it crisp and be sure to do it before you install it as its much easier, takes a whopping 10 minutes to do with the trans on the ground).

If it wasn't for being turbocharged I would not change from the w58, but to hold the power that I am running it takes a heavy clutch and I am not a fan of the clutch. otherwise with a more stock like clutch, its a great trans. there is a reason the mk4 n/a got only the tripod version of the w58. its nice and crisp.

 

^^ I think you've made the right decision, Salim!

I don't personally know enough about the best adapter, bellhousing and clutch combination for 1UZ applications but I think sticking with an organic face clutch disc should be what you'd want for drivability.

You can get a 1995-1997 SC300 W58 or the 1993-1997 MKIV Supra W58. Same transmission and shifter design.

The driveshaft should be the standard SC300 W58 type front shaft. To my knowledge you should not need to change the rear section of your driveshaft (someone please correct me if I'm mistaken).

The transmission tunnel, if you want to swap in a new one like factory (not required) can be:

P/N for a 1995-97 SC300 5-speed
P/N for a 1993-95 Supra M/T (5-spd NA or TT 6spd)
P/N for a 1996 Supra M/T NA 5spd (no TT 6spd in '96)
P/N for a 1997 Supra M/T (5spd NA or TT 6spd)
P/N for a 1998 Supra TT 6-spd (no NA 5-spd in '98 just like the SC300)

And you'd use the same rubber gasket and insulator parts that would go onto any 95-97 SC M/T. I'm not sure if the MKIV equivalent internal rubbber boots are the same but they probably are.

 

if you are coming from an automatic car, I want to say you do not have to change the tunnel for the remote shift transmission you just need to make the hole larger as the auto hole is pretty close to the right spot already.
Changing the tunnel would make it very OEM though.

 

Sprung and full-face are two terms your clutch needs to have if you want it to be similar to OEM. Even the material isn't as critical as those two things.

My Spec stage 3+ is full face and sprung and quite street friendly (minus the cams)

On the other end of the spectrum, my 350Z has an "organic" carbon Tilton twin disk which is NOT sprung and only has 4 pucks instead of being full face. You can't take off from a stop sign without reving it to 3000rpm. There is no "slip." Just OFF and ON.

 

This is a great find and good info here, Ive noticed the first gen W58s 92-94 had some second gear synchro problems that I have not noticed in the 95-97 tripod version. I would feel more comfortable with the tripod W58 or a low miles Supra W58 if one were to go this option of putting it behind the 1UZ although the motor is not much more powerful than the 2JZ-GE the torque comes at a lot lower rpm and it is a lot less subtle so hence getting a Low miles W58 will be the best bet. Most early SC W58 have more than 150K on em.

 

One other thing what driveshaft setup are people using for the W58 1UZ or does it have to be custom?

 

I am still waiting to hear a confirmation that for conversion, all i need is the small piece of the drive shaft from SC300 [I can reuse the long shaft from my SC400].

1/2 inch adapter plate, should require a shorter drive shaft, but the lateral movement give (as the rear axle moves up and down fixed radius is not maintained) has the margin, when SC300 short portion is used.


I need suggestion on flywheel too.

Any thoughts about the possibility of using SC300 flywheel and clutch and having the flywheel milled down to match the angle of the one I take off from SC400 [assuming the did and gear pitch would match the one from GS400].

Salim

 

the length of the motors are different, so the 1/2 inch wont make it a differenc eof 1/2 inch perfectly, you will have to see where it all is ending up once mounted. also the toyota driveshafts slip into the rear and have extra length so a little bit here or there will be fine its designed like that. I think front half from a manual connected to existing rear half.

flywheel they make 1uz flywheels now from a couple of shops.
A 2jz flywheel would have to be modified, how much I am not sure, but most people start with a 3vz flywheel.
you could start with a 3vz (toyota v6) flywheel and have the bolt holes opened up, v8 has a larger diameter spacing.
the 3vz has the correct diameter starter ring gear and the teeth are facing the correct direction (unlike the 3s-gte flywheel which eats up UZ starters).
Also the 3vz flywheels are very reasonable in price since you also have to modify them.

nowadays though companies make a 1uz flywheel that will accept the typical toyota pull type clutch (3vz, 2jzge, 7mge etc...). This is the best way to go unless you want to machine the 3vz flywheel.

There may be other options but nowadays since you can get a 1uz flywheel, its a no brainer as before the only choice was to modify. there is no bolt on flywheel. the 2jz ones the bolt holes are also off but there was another reason to use the 3vz I forget maybe it was to do with spacing?? I just know that is what most people use.

 

Hi Salim!

i used a 97 Supra W58 Tripod, installed with a kit from 1uzfeswapkits with the T56 throwout bearing. The flywheel bought i from bolt-perfomance, is a 9kg steel. Clutch is a Spec 3S-GTE stage 5 pressure plate and now a Stage 3 disc, but i change this to a 3+, the 3 is to heavy. The original tunnel for a MT is not new to buy :/ i build my own plate. You need a SC300 driveshaft, this is a 2-piece shaft, the SC400 is also a 2-piece but not with flange, is a slip-on-shaft! i had my problems. at least, i bought a front shaft from a supra the rear from a Soarer in UK (i´m from Austria/europe), a shop balanced the 2-piece shaft correct, changed one joint and installed a new bushing in the rear to center the diff. look in my thread, maybe some good ideas and informations for you my thread link

for standard power is the W58 good enough, shifts smooth and makes much fun

greets

Tom