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Hi,
New here and having a really hard time locating my particular clutch slave; pictures attached. It is marked S2 on the casting. To add to the complication, the 12a motor and early 5-speed gearbox are in a converted Lotus 7 so I can't refer to a vin number for the correct part. Gratuitous pic attached.
I can find very similar, early RX7 slaves but everyone of the options are the incorrect length, have different mounting tab locations, and the return spring retainer (the triangular tab 90 degrees from the mounting tabs) is missing. Any guidance would be greatly appreciated!
given the mounting points and short throw it also doesn't look like it would work with any rotary transmission, so it's unlikely it even is for a rotary car transmission. you'd be better posting pics of the trans and find some identifying serial numbers on it. google lens wasn't even helpful with those slave cylinder pictures so you'll need to give a little more info.
Last edited by notanymore; Apr 28, 2025 at 09:50 AM.
Mystery partially solved. My gearbox is close ratio from an RX-4 and I'm told it is also the same (or very similar) to the gearbox in an RX-5. At any rate, I still can't find the slave for it. Best info thus far is to use a '87-'91 RX-7 clutch slave. The RX-7 part bolts up perfectly but the banjo bolt thread size and pitch is different and I need to fabricate a different length push rod. Thanks for the replies on this.
@elwood Thanks for the observation; I have a bolt-in diagonal but I take it out when the passenger seat needs to be used.
you may just have to do some trial and error and see if the later model ones will work, they appear to have more throw in the bore which isn't necessarily a bad thing for wear properties using the extremities of the bore like that one used. minor issues being you'll have to bend the line some to get it fitted and possibly modify the slave rod length.
another common thing i tend to do is just swap the pistons out with more readily available ones from parts store slave cylinders. assuming the bore of the old slave is still usable(alot of the time they are not). this also leaves me the ability to warranty them out in less than a day. in this case the spring length on the plunger likely needs to be swapped as well. personally i'd just try to make the more common FC one work somehow.
it is an alternative, if you don't want to mess with making an adapter line.
Last edited by notanymore; May 4, 2025 at 02:53 PM.
Just FYI, I.am 99% sure that all nonturbo slave cylinders are physically interchangeable. I encountered once a pushrod length issue but that was easily solved.
If your hoses are from an RX-4 then yes you need a '79-80 slave for the correct thread pitch. It's physically identical to an '81-82 and GSL-SE slave cylinder except for that. (83-85 12A had a weird bleeder position for access with the oil cooler used on those engines, but they still fit the same)
For anyone curious, this is the outcome. Confirmed the gearbox is the RX-4 variety and the clutch slave I went with is the 86-91 RX-7 R2 part with matching banjo bolt. Apparently, you can use the earlier non-turbo RX-7 part as well. Pic isn't super clear as the part is obscured by the two breather lines. Thanks for everyone's help on this.
just for completeness the FC NA cylinder FB01-41-920A is really similar to the FB parts
the Turbo, F044-41-920C has the mounting ears in a different place, but other than that its the same (might be a different pushrod length, but those are easy to swap)
