Will An 87-92 Toyota Supra W58 5-speed Bolt Into My 93 Sc300 5-speed?

SC300Drifter · December 28, 2008

Hi everyone! After 215k miles my 1st & 2nd gears disappeared in my W58 5-speed transmission, I always read that 3rd gear was the weakest link in the W58. I am having a very difficult time locating a manual transmission from an SC300 or 93-98 Supra for a reasonable price. After searching I found that W58 transmissions from previous year (82-92) Supras are everywhere and fairly cheap so I picked one up locally for $150 out of a 1988 Toyota Supra NA.

I did a side by side comparison of the original SC300 W58 and the W58 from the 88 Supra:

1. The bellhousings are different, one is for a 2JZ and the other is for a 7M-GE

2. The rear section of the transmissions are slightly different

3. The transmission mounts are located in different locations with a different hole spread

4. The shifters seem to be in slightly different locations

I was aware the bellhousing would have to be swapped when I purchased the transmission but I didnt (still cant) find any information on the rear section of the transmission being different or interchangeable between the different years of W58's.

I was going to install the transmission myself but decided to have a shop do the job since I couldnt find any info on this subject. I had my car towed to the shop, a couple of days later the mechanic called me and told me that the "new" transmission will not work in my SC300 because:

1. The transmission mounts are different

2. A shaft inside the transmission is different diameter (i think thats what he said...)

3. The different diameter shaft requires a larger bearing

I dont know too much about transmissions and have never taken one apart but it seems to me that the transmission mounts would be resolved once the SC300 rear section is swapped to the new tranny and the shifter would also be relocated to the correct spot. I dont know what shaft or bearing my mechanic is talking about, could it be the mating section for the driveline or is there an internal shaft/bearing that is likely to be different? Im not even sure if the shop "tore-down" the transmissions to confirm non-interchangability. I would love to have this car back on the road quickly, is my mechanic incorrect or can the MKIII transmission bolt into the SC300 without custom modification (can a simple swap of the bellhousings and rear-sections be done)?

Is my only option really to source down a W58 from an SC300 or MKIV Supra? Thank you so much for your help!

don corleone · December 29, 2008

sorry not much help here but the bolt on my LS trans is 30mm and i needed a deep impact socket to get it off. once you do that you can remove the extension housing so you may be able to check the compatibility yourself. this is funny because i was just researching the W58 trans since i was going to do a swap with the good ol' 1uz and a W58 into a roadster or coupe. i was thinking a old 300Z or a Supra. the supra is the most logical choice for me since it already has the W58. if you check out Lextreme.com there is a lot of info on the W58 trans look for the engine swap/conversion article.

Good luck :cheers: