xspsi6

iTrader: (31)

Ok so my last thread got erased and the mods here have told that my posts are "stupid" however this is the 1st I have ever heard of this and I am almost sure it does not work however I wanted to run it buy some of the people here who might know with 1st hand exp.

Also sorry if it has been covered before however my searches did not yield any results on the subject.

99SC42

iTrader: (44)

The guy that made that video , name is Nick and i am sure he will share his findings with you.

it doesn't work , sorry.

https://www.clublexus.com/forums/sc-...00-1jzgte.html

xspsi6

iTrader: (31)

Ok maybe I missed the story behind why he said it would work? I Know it does not but I just wonder why he said this?

Bigzavs

iTrader: (4)

they are the same spline, i have one sitting in my garage and just recently checked it

xspsi6

iTrader: (31)

Haha now I am really confused ? So if the spline is the same why would it not work?

Bigzavs

iTrader: (4)

it is most likely that its too long, it is considerably longer than the manual trans driveshaft.

xspsi6

iTrader: (31)

So the front section needs shortened? Could one just change the yoke?

xspsi6

iTrader: (31)

Here is a pic of my sc300 driveshaft front section and I looked under my friends mk3 turbo and the appeared the same length however I did not have time to measure.

Shanman89

2JZlex has done it in his SC400.

KahnBB6

iTrader: (5)

xspsi6, the auto SC300 front driveshaft will FIT because the splines and inner diameter are exactly the same as the R154 front shaft... but it is TOO SHORT.

I was sold a "Soarer R154 front shaft" by someone who had a Cressida project. He either didn't know any better or deliberately cheated me but my engagement was barely more than 0.5" on the splines. I was OK to drive that way only because I'm not turbocharged yet. Even with a stock 1JZ you may very well damage the splines if you accelerate at full tilt. Trans oil leaked out the rear tail housing like a sieve and smelled horrible as the splatter burned off all over my undercarriage.

The solution was to locate an MKIII R154 front shaft. That solved everything other than that the collar came very close to hitting the rear of the transmission (which I believe has to do with aligning the swapped-over SC center bearing with exactly the right amount of distance) which I subsequently was able to remedy. It's now drive-and-forget.

What you can do is cannibalize the yoke and carrier end of the auto SC300 shaft to make a custom one-piece but you can also get those things already made from a place like DM. You'd want to make sure those bits are in good condition because they aren't serviceable to my knowledge.

I highly recommend you do not try your luck with the SC300 auto front shaft, sorry.

Edit: I just looked at the video you posted above and by now I am sure that guy had the same experience I did unless he had planned to measure and weld a new driveshaft tube to give it the couple of inches or so more (don't quote me on that) that it needs to equal what a Soarer/MKIII R154 shaft would measure at.

2020 Edit/Update: For reference a Supra MKIII R154 front driveshaft does work but is technically 3/4" (0.78" or 20mm) too long as compared to a Soarer R154 front driveshaft. Usually there will be no issue with the MKIII shaft but the R154 rear dust cup has to be removed and there will be little to no extra slip clearance with the driveshaft's own cup right up against the back of the R154's rear tail housing. This can and does work (with the R154 rear dust/splash cup removed) but ideally whichever front driveshaft is used it should be changed to match a Soarer R154's front driveshaft length.

2023 Edit/Update: Additonal note... you actually CAN use an SC300 Auto front driveshaft.... so long as you take it to a local driveline shop and have its barrel extended by *approximately* +50mm (+1.96"). Then it will be at the correct length. It will need to be rebalanced and repainted after being custom extended of course. At that point you will have built yourself the replica equivalent of a JZZ30 Soarer R154 front driveshaft since apart from the factory length differences they are otherwise the same. So extend an SC300 Auto front driveshaft to the correct length and you will have a near-factory driveshaft solution for an R154 swap.

But if you try to plug in an SC300 Auto front driveshaft without extending it to the correct length you cannot make it work. Transmission oil will spew out the rear of the R154 coating your undercarriage and running the transmission low on fluid. Also the splines will barely contact making it a BIG NO for any boosted car and even a huge concern for a non-boosted car to protect the splines under load. Don't do it. However if you modify the SC3 A/T front driveshaft accordingly and then all will be fine.

Shanman89

^You are correct Sir. My apologies. He however is pointing out that the MK3 front half does not work with the Sc300 auto?

As quoted from 2JZlex's Auto to R154 swap thread

"Just to kind of wrap up some of the myths and facts about all of this,
The MKIII pedal assymbley WILL work, but there modifications that need to be made
A W58 WILL work, but you have to use the crossmember also for simplicity, and drill out the holes where it bolts to the frame
A 1jz flywheel WILL work
A 1jz bellhousing WILL work
An MKIII stainless steel clutch line WILL work, (for length I mean)
An MKIII driveshaft WILL NOT work, it makes it too long.
You do NOT have to get different bellhousing bolts, the ones from the auto work great.
The starter WILL fit perfectly, sits in stock location and everthing.

Some things that should be mentioned. As of right now I am using the auto driveshaft from an SC300, it works ok and bolts up bolt it is slightly too short. I am going to have a custom one-piece made shortly. I lost the speedo sensor somewhere so I don't have a speedo right now and am looking for one asap but I do think that they use the same 3 pin sensor and works perfectly, I will try and confirm this whenever I get it in. The clutch I used is definately going to take some getting used to, and is the limit for daily driving for sure, but it is SO fun to drive, it feels like my own little racecar now, absolutly amazing.

So was it worth it? Total cost of swap: $2,240. Amount of cusswords: 304. Having an amazing sexy clutch and 5 speed behind a singled 2jz: priceless."

KahnBB6

iTrader: (5)

^^ I learned something there too, Shanman89. There must be a difference in the SC3/5-speed rear shaft and the SC3/auto rear shaft that I wasn't aware of. My car is an original 5-speed so maybe that is why only the MKIII R154 front shaft worked for me but may not work for others. If I read correctly... I think the SC400 rear driveshaft is definitely different from any of the SC300 rear driveshafts, owing to the confusion. It's news to me but honestly I've taken the most OEM route possible and have tried to do very little custom work. My crossmember is modified and welded from a 1982-85 W58 Celica though, hah.

As for it being worth it... oh, absolutely. I can't wait until I actually get my swap motor finished and installed but even NA I love the feel of the R154. Gearing is even slightly more aggressive than with the W58 in 2nd and 3rd-- hey, I take what I can get for now My cost was in the same ballpark and then some.