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Can someone please help me identify the below RX7 gearbox type/year and rear housing type/year.
My understanding is the gearbox and end housing are from 2 different types of RX7 gearboxes. I'm trying to identify which model RX7 the parts are from.
^shifter location, so it's definitely pre 81. never actually seen an fc, fd, or rx8 trans but don't they all have the shifter farther back, right over the end of the output shaft from 81 on? the one pictured looks identical to the one i have from a 74 rx4.
thanks, rxtasy3. the shifter location makes sense. honestly didn't think about that.
i was more curious what it was about the mount that j9fd3s used to identify it.
actually, i guess i had a brain-fart earlier, too, because the mounting on the Rx-8 is totally different, so i would probably catch that in a photo. no way you could mix it up with the older cars.
what are the telltale signs one would look for to distinguish it from say, the T2 or Rx-8 5 speed trannies?
the 6-spd RX8 transmissions don’t have those two bolt-on cover plates on the main 5-rib center housing and the bellhousing is integral to it, not bolt-on.
The RX8 5-spd is a push-clutch version of the FD trans and does have those though. It wasn’t offered for North America, but they’re are a few kicking around from JDM importing.
thanks, rxtasy3. the shifter location makes sense. honestly didn't think about that.
i was more curious what it was about the mount that j9fd3s used to identify it.
actually, i guess i had a brain-fart earlier, too, because the mounting on the Rx-8 is totally different, so i would probably catch that in a photo. no way you could mix it up with the older cars.
the 74? -85 mount looks like this, and it bolts to a flat spot on the tail housing
the FC mount, looks like this, and the spot on the tailhousing is not flat.
and then the FD and later cars don't have a trans mount at all, its got the PPF mount studs. that thing at the back is some kind of damper. like Team says its an FD transmission with a weird clutch. its a turbo size ring gear, but NA sized disc...
the 6-spd RX8 transmissions don’t have those two bolt-on cover plates on the main 5-rib center housing and the bellhousing is integral to it, not bolt-on.
The RX8 5-spd is a push-clutch version of the FD trans and does have those though. It wasn’t offered for North America, but they’re are a few kicking around from JDM importing.
thanks.
the 6 speeds, i know through photos only. i've never had a reason to take mine out of my car, so i have not seen it in person just yet.
now, as for the 5 speed, i actually have one and it's been sitting in the corner, in the garage for a few years now. what i did NOT realize is that it was the FD tranny. i knew they were both R-types, but i thought there were more differences besides the bellhousings/clutch setup.
Originally Posted by j9fd3s
the 74? -85 mount looks like this, and it bolts to a flat spot on the tail housing
the FC mount, looks like this, and the spot on the tailhousing is not flat.
and then the FD and later cars don't have a trans mount at all, its got the PPF mount studs. that thing at the back is some kind of damper. like Team says its an FD transmission with a weird clutch. its a turbo size ring gear, but NA sized disc...
i wasn't fortunate enough to ever see one of the original R-types/ribcases, so i never knew about the flat spot, so yeah the mount went totally over my head. thanks for the lesson! As a matter of fact, the Rx-8 tranny that i have is the only ribcase i've ever owned, so ....
the FD is easy to ID because of the bellhousing/clutch though, so i'd never be fooled or stumped by a photo of one.
i also did not know about the Rx-8 5-speed's clutch. i knew it was the big flywheel, but had no clue about the small clutch, so thanks for that, too.
got a few more questions, but i will leave for YOUR thread that i just finished reading.
Mazda Motorsports sells the RX8 version (never was a USDM option); you’d have to swap the bell & tail housings along with the shifter rods (or keep the BH and switch to a push clutch), but then you’d get 1st - 3rd gear triple synchro rings and some other internal upgrades.
forgot about this, observation on the RX8 5-spd vs the FD version, may not be as strong as a result:
Originally Posted by AN7
Hey guys, I dont know if eventually anyone with big power tried the RX8 5speed manual but from my understanding and after an examination of an RX8 5sped box, it should be weaker. I don't know by how much, but to my understanding, in order for mazda to implement the 3ple cone syncros on the gears the narrowed them, thus 1st 2nd and 3rd on the main shaft looks like they are narrower than the FD's. In general, Narrower gear teeth = weaker, if I understand correctly fds box has double cone.
Originally Posted by AN7
4th and 5th are exactly the same as nothing changed there. The corresponding gears on the secondary shaft looks the same width which is very weird because if they didnt do it for the syncros why norrow down the main shaft gears and not the secondary shafts. I cannot be 100% sure cause I dont have an FD box to measure and compare them and my assumptions are based on what I can find on the net. So if anyone here have one laying around please take some detailed photos or even measurements.
For the sake of it
This is how 3rd(left) and 2nd(right) looks like in the FD box. Pay attention to the gap between the engagement teeth and the gear teeth on both gears. They are pretty close.
And here is how they look like in the RX8 box. Notice that the gap is much wider, I would say almost double and have oiling holes to the syncros and the shaft bearings.(same applies for the 1st gear). Thus in order to widen this gap, they had to narrow down the gear teeth.
09-01-21, 12:36 AM
the shifter location makes sense. honestly didn't think about that.
