Sc300 mk3 w58 swap
03-12-16, 03:38 PM
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Sc300 mk3 w58 swap
Hey everyone I'm about to get a mk3 w58 transmission and I was curious if I can swap it into a early model sc300 with the stock 2jz thanks everyone for the future help.
03-13-16, 05:12 AM
#2
This has been done a couple of times very recently but really isn't recommended. I would hold off and find any SC300 or MKIV Supra W58.
You technically *can* make it work but it's going to involve much more effort than using an SC300 early W58 or an SC300/MKIV Tripod W58.
The MKIII W58 is much weaker than the SC300 or MKIV versions largely due to having an aluminum sandwich plate. It also requires a Marlin Crawler VSS convertor, a 2JZ-W58 bellhousing, an SC300 W58 shifter extension housing and internal arm swap (or a custom version of the same via a cutting and jig welding job to extend the shifter housing), and finally a custom transmission crossmember solution identical to the options available when swapping in an MKIII R154 transmission.
It's roughly the same amount of work required to adapt an MKIII R154 to your SC. The SC W58's (both versions) or MKIV W58's hold more power and install more directly to the SC chassis.
When you say "early" SC I assume you mean you have a 1992-1994 model? Or 1995? Starting from an A/T SC300 means it's really the same procedure for all of them up to 1998-2000 models (which requires some extra wiring). The A/T transmission tunnels all need to be cut unless you plan to swap in a 1992-94 M/T tunnel or a 1995-97 SC or MKIV Supra M/T tunnel.
You technically *can* make it work but it's going to involve much more effort than using an SC300 early W58 or an SC300/MKIV Tripod W58.
The MKIII W58 is much weaker than the SC300 or MKIV versions largely due to having an aluminum sandwich plate. It also requires a Marlin Crawler VSS convertor, a 2JZ-W58 bellhousing, an SC300 W58 shifter extension housing and internal arm swap (or a custom version of the same via a cutting and jig welding job to extend the shifter housing), and finally a custom transmission crossmember solution identical to the options available when swapping in an MKIII R154 transmission.
It's roughly the same amount of work required to adapt an MKIII R154 to your SC. The SC W58's (both versions) or MKIV W58's hold more power and install more directly to the SC chassis.
When you say "early" SC I assume you mean you have a 1992-1994 model? Or 1995? Starting from an A/T SC300 means it's really the same procedure for all of them up to 1998-2000 models (which requires some extra wiring). The A/T transmission tunnels all need to be cut unless you plan to swap in a 1992-94 M/T tunnel or a 1995-97 SC or MKIV Supra M/T tunnel.
Last edited by KahnBB6; 03-13-16 at 05:15 AM.
03-13-16, 10:16 AM
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The reason why I asked is because I'm getting ready to acquire a mk3 supra w58 for $150 without a bellhousing. And I know they will also fit into the mx83 cressida but I was curious if it will fit into a stock sc300 without any problems.
03-13-16, 11:09 PM
#4
I understand but I would not say that there are no problems installing an MKIII W58 into your car. With the JZ bellhousing swap it will bolt to the engine but the above changes will have to be made to make it work with the rest of the chassis.
Besides their weaker design compared to later W58's it's not a straightforward bolt in swap. That's why I recommended holding off and finding an SC300 or MKIV W58 instead. Less work to bolt it in and a stronger transmission overall.
The MKIII W58's indeed will fit MX83 Cressidas (just the same as MKIII R154's will). The raw gearbox casing shape physically doesn't change with later generations other than the tail mount hole arrangement (which is very significant), however the shifter housing does need to be modified to get the shift lever in the correct spot even with the required "swan" bend type. The shifter hole will be far too close to the radio area without at least an SC300 length housing. MKIII W58's have an extension housing version of their own to fit into the 1986-92 Supra chassis but this still isn't as long as the early SC300 W58 extension housing. Unless you compare them side by side or are measuring the length of the housing it can be confusing at a quick glance.
Then there is the aforementioned bellhousing swap and the required Marlin Crawler VSS sensor adaptor (or swapping in a factory Toyota VSS drive).
Also, the transmission mount needs to be from an MKIII Supra and the crossmember you use will have to be a custom solution normally used for MKIII R154 transmissions into SC's:
A) 82-85 Celica W58 crossmember that is cut with plate steel extended and welded slightly on one side.
B) Driftmotion's MKIII R154 crossmember and mount kit which requires drilling your original SC crossmember. This approach extends a bit beyond the chassis slightly by using 1"-2" spacers. Can't remember the exact clearance figure. The mount they provide bolts in exactly the same way as with an MKIII W58/R154 mount only it's much bulkier.
C) CXRacing makes a fully custom crossmember which also uses the MKIII W58/R154 OEM style rubber mount.
Besides their weaker design compared to later W58's it's not a straightforward bolt in swap. That's why I recommended holding off and finding an SC300 or MKIV W58 instead. Less work to bolt it in and a stronger transmission overall.
The MKIII W58's indeed will fit MX83 Cressidas (just the same as MKIII R154's will). The raw gearbox casing shape physically doesn't change with later generations other than the tail mount hole arrangement (which is very significant), however the shifter housing does need to be modified to get the shift lever in the correct spot even with the required "swan" bend type. The shifter hole will be far too close to the radio area without at least an SC300 length housing. MKIII W58's have an extension housing version of their own to fit into the 1986-92 Supra chassis but this still isn't as long as the early SC300 W58 extension housing. Unless you compare them side by side or are measuring the length of the housing it can be confusing at a quick glance.
Then there is the aforementioned bellhousing swap and the required Marlin Crawler VSS sensor adaptor (or swapping in a factory Toyota VSS drive).
Also, the transmission mount needs to be from an MKIII Supra and the crossmember you use will have to be a custom solution normally used for MKIII R154 transmissions into SC's:
A) 82-85 Celica W58 crossmember that is cut with plate steel extended and welded slightly on one side.
B) Driftmotion's MKIII R154 crossmember and mount kit which requires drilling your original SC crossmember. This approach extends a bit beyond the chassis slightly by using 1"-2" spacers. Can't remember the exact clearance figure. The mount they provide bolts in exactly the same way as with an MKIII W58/R154 mount only it's much bulkier.
C) CXRacing makes a fully custom crossmember which also uses the MKIII W58/R154 OEM style rubber mount.
Last edited by KahnBB6; 03-13-16 at 11:14 PM.
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