will an s5 TII bolt right up to all the s4 tII stuff?

 

The shift lever is slightly diffrent if i recall correctly, and you will need to keep the flyhweel with your engine, as the flywheel is balanced to your engine. other then that i don't see why not.

 

the only thing you should have to change are the actual transmission mounts, you'd have to source the s4 ones to make the s5 transmission fit on your car (if your car is a s4)

 

its an 87 base model with full a TII swap (drivetrain and suspension).

 

This is not correct. You need to use the corresponding crossmember for the trans being used not the year of the car. S5 TII Trans = S5 TII crossmember

The S5 shifter has a smaller thread for the **** (then the S4) it also has a nylon insert in the shifter linkage and at the pivot pin groove bushing.

The quick answer is Yes, you can install the S5 TII trans as long as you have the correct crossmember.

 

Didn't know about the crossmember from a manual to a manual, i've only ever put s5 manuals in auto s4's and s5's. I thought the manual transmission would all use the same corssmember, thanks for the correction.

 

Strange as it may seem there are 5 different crossmembers for the FC

86-88 Manual Trans non-turbo
86-88 Turbo
86-92 Automatic Trans
89-92 Manual Trans. non-turbo
89-92 Turbo

 

They give different part numbers, but yet I know all years interchange. (Don't know about auto)

 

Incorrect. The S5 and S4 cannot be swapped, they mount to the trans completely differently, side of the trans vs. the bottom. The N/A and TII in a particular series can be swapped but they will not bolt up to the chassis. The mounting holes are offset differently on the crossmember. The auto crossmember is completely different then all the manual trans.

 

More importantly, are there any differenced in gear ratios or strengths? In other words, is there an advantage of using one over the other (mounting being equal)?

 

84-85 13b GSLSE 3.622 2.186 1.419 1.00 .807
1986 RX7 Non-Turbo 3.475 2.002 1.366 1.00 .711
87-88 RX7 Non-Turbo 3.475 2.002 1.366 1.00 .697
89-92 Non-Turbo w/o LSD 3.475 2.002 1.366 1.00 .697
89-92 Non-Turbo with LSD 3.475 2.002 1.366 1.00 .756
86-88 RX7 Turbo 3.483 2.015 1.391 1.00 .762
89-95 RX7 Turbo 3.483 2.015 1.391 1.00 .719

5th gear varies in ratio between series of the same trim.

We find the S4 trans and diff hold up to more abuse then the S5. The Turbo LSD simpley because it is a Clutch style vs Viscous

 

banzai your telling me a s5 t2 tranny cross memeber + mounts will bolt right up to a s4 chassis?

I feel bad that I'm giving out misinformation if that's the case

 

That is correct. A S5 TII trans with the S5 TII crossmember bolts directly into an S4. The rubber mounts are all the same. There is a Series specific trans bracket that bolts to the trans, then the rubber isolators, then the Series specific crossmember

This is an S5 TII, notice the trans mount Y bracket has the holes on the sides, the S4 has them on the Bottom. Also notice the offset chassis mounting holes, these change from front to rear depending on Turbo or N/A

 

So, the 5th gear is the only difference (probably an attempt to save gas) in the ratios? I'm not worried about the LSD, I'm worried about the transmission its self. I dropping my S4 and it is gone, and swapping in an S5 as they are more readily available from Japanese importers. My car is a GSL-SE by the way.

 

i did not think you could use a stock S4 clutch and flywheel with a s5 trans?

 

The S4/S5 clutch is exactly the same and bolt to either S4 or S5 flywheel, the flywheels are balanced to the engine.

http://banzai-racing.com/store/86-91...lutch_kit.html


I had no idea people were so confused on this subject.

 

why do they have different flywheels, clutches, release bearings?

I had a custom clutch set up that started out as a ACT set up, it would not fit over the front cover of the s5 trans, I had to change the front cover of the trans. but they sell only one front cover, meanwhile the bearing and fork would not work.

I had a hell of a time with that **** over a $45 front cover swap.

 

The only diffence is between Turbo and N/A not between S4 and S5

Front cover of the S5 trans? I have no idea what you are referring to. There is a bellhousing, still no difference. S4 and S5 flywheels vary in weight not design.

 

there is a removable front cover on the TII trans, it was different from S4 to S5.
They also sell 2 different clutch forks.

Aftermarket clutches fit all TII, but stock are different.

2 different release bearings also, a s4 bearing will not fit on a s5 front cover, the forks will not interchange either.

I never understood how aftermarket stuff can cover the entire range, but stock is all different?





Transmission Front Cover with Seal
It is always a good idea to replace the front seal on the transmission when replacing a clutch. What we are finding is considerable wear on the transmission front cover from the continual release bearing movement. If worn too much, the pressure plate will fail prematurely from release bearing side movement and misalignment.

 

Where are you getting this info from? It is greatly flawed.

Even the picture you just linked to list it as a 86-92 Turbo front cover, part number does not change neither does the part. http://www.mazdatrix.com/g3.htm

The clutch fork IS interchangeable as well as the release bearing, this is why the aftermarket parts all fit both series

 

I listed the front cover because you said there is no front cover, just a bellhousing.

My information is not flawed. Im not imagining that the throw out bearing and fork I bought brand new from Mazdatrix did not fit on my front cover, I had to buy a new front cover.
Again I ask you if there is no difference then why are there 2 different forks and different release bearings?

We are not crazy, there were 4 different rotary mechanics stumped by this, the solution to my issue was buying a new front cover. The trans was a S5 Jspec trans.

Why does Mazda sell different S4 and S5 TII clutches, pressure plates, release bearings and clutch forks if they are all the same?

 

im going to have Roan come in and explain it as well since you think I am flawed, meanwhile I wish you to explain to me what Mazda's reason for selling series specific TII clutches, forks, release bearings and pressure plates, if they are interchangeable then why not just sell one for all TII trans? What is your explanation?

 

banzai is correct with regard to the mounting brackets.
and Rob is definately correct with regards to the front cover and T/O bearing issue.

the issue is this. we tried installing a Series 5 clutch, flywheel and T/O bearing with a series 5 trans. (it apears someone had changed the front cover pictured above to a series 4 one). everything bolts up as the flywheel diamerters are the same ect.. but the throw out bearing will not fit on the trans fork. no big deal (so we thought), we had a series 5 fork on the shelf, well the series 5 fork will not fit with the series 4 front cover. myself and 3 other experienced rorary mechanics all witnessed this and I can tell you for a fact it doesn't work. we bought the series 5 front cover and everything works fine

 

You can argue all you want, there is only one part number for the front cover, there is no S4 or S5, just 86-91 turbo. N302-16-2210

The clutch and pressure plate have nothing to do with the front cover, so there would not be any issue with fitment on the ACT set up.

ACT sells exactly the same release bearing for every FC clutch kit, it does not matter if is it a N/A, TII, S4 or S5 it is all the same part RB091

You guys are really going to try to convince everyone that ACT, Centerforce, Exedy, ect have all put together the wrong clutch kit for either the S4 or S5? It is much more likely you guys got your hands on a bad part somehow. A mis-marked release bearing maybe?

The Clutch fork didn't fit the Front Cover? They do not even make contact with each other. The clutch fork attaches to a pivot ball and then slides the release bearing up and down the front cover.

Again sounds more like you had a mis-packaged release bearing. From what I am hearing it was the release bearing that was the entire fitment issue. Not the Clutch, flywheel, clutch fork or even the front cover.

BTW: Mazda created new part numbers for the S5 clutch discs & PP because the stock 86-88 clutches are 240mm, the 89-91's are 235mm. They can be used in either series, the spline stays the same.

 

Alrighty, I took a few minutes out of my day to snap some pics. Honestly, if it took four "rotary mechanics" to install a clutch and release bearing, I have to question the caliber of the mechanics. There is nothing even rotary specific about a simple clutch install. I certainly would not recommend them for a RX-7. Sounds to me like Robxx7 was getting shafted.

Here are 3 clutch forks and a release (TO) bearing, S4 N/A, S4 TII and far right S5 TII. Difference is fork fingers are a little thicker on S5, which is the reason for new part number and would be an upgrade for the S4.



Same release bearing in S4 and S5 clutch forks, no fitment issues:





I figured I would go to opposite extremes with the trans, here is an S4 N/A trans with the S5 turbo clutch fork and S4 release bearing:



Now the S5 TII trans with the S4 clutch fork and S4 release bearing:



Absolutely NO fitment issues and everything is interchangeable. Sorry Rob but you got screwed.