The SC is my first 2JZ platform and the 5-spd in my 94 is very notchy. It's not terrible but definitely nowhere near as smooth to engage as the newer modern cars. It take a little force to engage it into each gear. All 5 gears and reverse are the same. Maybe I just have to accept this is how 25 year old trannys are? My hopes are it could be better. When its in gear the handled doesn't have a load of play, it's fairly tight so I don't think the syncros are shot. In my experience tighter syncros can make it even harder to shift. Just seems like engaging the gears requires more force than it should. Can anyone tell me if this is just the normal W58 or is there something internally that could be causing this?

The only reason I'm concerned is I'm only pushing around 280-300whp and I'm about to raise the boost. So if the tranny being "notchy" is a sign of something wrong I may want to address that before pushing more torque, since I can't really afford an R154 or similar right now. Any thoughts would be appreciated! Thanks y'all!

 

no, go get it checked out, and dont go above 300hp on a w58. if you cant upgrade to a stronger trans then dont up the boost.rebuild the w58

 

What oil are you running in it?

 

^^ W58's have been used for boost applications but it's not recommended. People's experiences vary considerably depending on how they drive and the age and condition of their W58's when paired with a boosted engine. Do not raise the boost at all and be gentle when shifting and applying throttle to the W58 if you're already on a boosted engine if you want to keep the gearbox in decent shape. A rebuild with all new bearings, synchros and new shifter bushings can restore a lot of the good feel a W58 was designed with but it's already being stressed near its maximum limit at 300whp. Be careful with your gearbox. How long it will last totally depends on how gently you treat it with your current setup. It was never originally designed to handle the shock-loading of sudden torque from a turbocharged engine.

Actually W58's were bolted to JDM only 1G-GTE 2.0L turbo I-6's but look up the power and torque figures for those: less horsepower and torque stock than a 2JZ-GE came with. The W58 was not meant for big power. It works fine with the SC400's 1UZ-FE because the power from those engines is a very linear 250-260hp at the crank and even with more torque than the 2JZ-GE it is a fixed and linear delivery of torque. Your engine is both well beyond that figure and delivering its power in a totally different way.

An R154, AR-5 or CD009 swap is highly recommended. And Redline MT-90 is the gear oil recommended for W58's and R154's.

 

Most everybody will tell you (as Kahn has) to run MT-90. This is solid advice, and may work for most drivers. However I choose a slightly different route that works for me. I run Redline MTL. I use mine in endurance racing and it just seems to shift and hold up better with less heat buildup. Probably sacrifices the synchros but definitely shifts better in my opinion. Might work for you given the power you are putting through it.

 

I don't know what kind of fluid the previous guy put in it but I think he changed it. But I've read stories of guys making 500+ on a W58 but even those people will say you're on borrowed time and they pop eventually. My goal is 400-450hp and whatever the torque ends up at is fine. I am pretty gentle on my cars but I have no faith in this tranny holding that power since I have no clue what kind of life the previous owner(s) gave it.

Is the R154 still the most affordable and easiest to adapt? The 6-speed seems fun but back when I researched it the price was pretty steep on the transmission alone, not including any additional fabrication or adapters.

 

If you don't know what fluid is in it, then this is very likely why it is shifting notchy. Just change it and see how it does. Then run it until it breaks, worry about what to put in it then.