Mazda Rotary Club

Cars by Model Type => 2nd generation RX-7's => Topic started by: shaunwil on September 02, 2011, 03:57:47 PM

Title: S4 & S5 EGI Gearbox Differences ??
Post by: shaunwil on September 02, 2011, 03:57:47 PM
Trying to source an S4 EGi gearbox but I\'m struggling for info !

Is there any easy tell tale signs if the box is from a S4 or S5 Egi car ?

Has anybody got any good images showing the differences ??

Shaun
Title: S4 & S5 EGI Gearbox Differences ??
Post by: Brett on September 03, 2011, 08:44:36 AM
Should be tons of EGI boxes around!
IIRC the shaft has a different number of splints from S4 to S5...
Title: S4 & S5 EGI Gearbox Differences ??
Post by: shaunwil on September 03, 2011, 11:27:10 AM
So is the S5 EGi box 23 splines as opposed to 22 on the S4 EGI ?

Shaun
Title: S4 & S5 EGI Gearbox Differences ??
Post by: bumpstart on September 04, 2011, 02:34:15 AM
AFAIK both s4/5 "M" boxes are 22 spline,, it is the turbo "R" box that is 23 spline
in s5T ( at least for oz, jap and US markets )
the "R" box gets a new V sided multi rubber mount,, and the casting block on the rear housing for the mount reflects this

not sure if this repeated in the NA series with the "M" box
( the s5 NA are not that common here and i can recall working on genuine stock examples only twice )






but at any rate you guys in brit and europe get unusual model delination and at different years from the rest of us so that can make a little confusing
you should quote your model number to make the comparisons easier

as a brief run down for the differences -


for us in oz we have full ECU control 1986 N326 ( s4 NA manual ) N327 ( s4 NA auto )
and then the VDI intake N350 ( s5 NA manual ) N351 ( s5 NA auto ) in 1989

US don\'t get the jap/oz N318 ( s4 turbo ) but instead get a revised n332
( which curiously uses the odd leading spark location housing carried over from the n326, with turbo exhaust insert )

all US and oz market cars get AWS, and so get features such as the 4 wire 5th /reverse switch , precat , and the extra idle up solenoids ( ABSv , ASv ) , and external EGR for some models
Title: S4 & S5 EGI Gearbox Differences ??
Post by: mpk490p on September 04, 2011, 10:30:42 AM
as far as i know Shaun any efi box will do just make sure it has the vents like the one on my photo
Title: S4 & S5 EGI Gearbox Differences ??
Post by: shaunwil on September 04, 2011, 10:31:04 AM
Cheers, that makes a lot more sense. The box Ross has does has a 22 spline shaft and a vee style mount so it\'s the later spec one.

Will give the guys breaking the 1990 car to see if it\'s the same. If not then I may have that box off them.

Shaun
Title: S4 & S5 EGI Gearbox Differences ??
Post by: shaunwil on September 04, 2011, 10:33:32 AM
Quote from: mpk490p;786323as far as i know Shaun any efi box will do just make sure it has the vents like the one on my photo

That could be the sign of the s4 box !

Will have a better look at the images.

Shaun
Title: S4 & S5 EGI Gearbox Differences ??
Post by: bumpstart on September 04, 2011, 10:42:29 AM
the dual vented bell housing is a feature of 12at and s4 ( and maybe s5 ) gearboxes
the V shaped casting for the multi rubber mount is an s5 trait
Title: S4 & S5 EGI Gearbox Differences ??
Post by: mpk490p on September 04, 2011, 11:02:09 AM
better shown here
Title: S4 & S5 EGI Gearbox Differences ??
Post by: shaunwil on September 04, 2011, 11:14:07 AM
Cool, so that makes the one Ross has a S5 Egi box. Can you see the vent from inside the bell housing ?

Shaun
Title: S4 & S5 EGI Gearbox Differences ??
Post by: mpk490p on September 04, 2011, 03:51:20 PM
from memory yes
Title: S4 & S5 EGI Gearbox Differences ??
Post by: shaunwil on September 04, 2011, 04:10:36 PM
I\'ll keep an eye out on the cars getting broke !

Shaun
Title: S4 & S5 EGI Gearbox Differences ??
Post by: shaunwil on November 16, 2011, 11:21:56 PM
Well to bring an old thread back to life.....................

Bought a 1987 EGI gearbox off ebay today ! Pictures all look correct. Will be fitting at the weekend with a fresh clutch (since mine feels like it isn\'t going to last much longer)

Shaun
Title: S4 & S5 EGI Gearbox Differences ??
Post by: grinder on November 17, 2011, 12:54:11 PM
sounds like a good weekend you have planned mate !
Title: S4 & S5 EGI Gearbox Differences ??
Post by: shaunwil on November 17, 2011, 05:23:21 PM
It needs to be back in one piece by Monday !

Your more than welcome if you fancy a tinker :D

Shaun
Title: S4 & S5 EGI Gearbox Differences ??
Post by: grinder on November 18, 2011, 01:17:54 PM
me and gearboxes arent the best combo ;)
Title: S4 & S5 EGI Gearbox Differences ??
Post by: shaunwil on November 18, 2011, 03:48:18 PM
Come and get some dirt under your nails :Giggle

Shaun
Title: S4 & S5 EGI Gearbox Differences ??
Post by: shaunwil on November 18, 2011, 06:17:22 PM
Checked the clutch on the spline from Clive and the no of teeth is right. Struggled getting the rear end off. Didn\'t realise I had to twist the case off from the selector pickup.

I\'ll Need to check the propshaft as well when I Pull it off so hopefully it will all work out ok.

Shaun
Title: S4 & S5 EGI Gearbox Differences ??
Post by: shaunwil on November 18, 2011, 06:19:18 PM
The other question I have is which way round does the stock clutch fit ? Pickup Boss is taller on the one side !

Shaun
Title: S4 & S5 EGI Gearbox Differences ??
Post by: shaunwil on November 20, 2011, 12:11:46 PM
Well just had a couple of snags to finish this morning and I\'ve just been out in the car. Seeing a nice reduced rpm at speed and the car is now much quieter, my old box may not have been all that well !

I found my clutch wasn\'t completely toast, was about 1mm above the rivets. Changed it anyway for the discounted one I bought of Clive :D I think my slave has a slight weep so that will be getting fixed in the near future too !

One thing that does worry me is I seem to have lost one of the engine to bell housing bolts ! I\'ve left one out of the top so will get a replacement quick. Car still seems ok to drive though.

Shaun
Title: S4 & S5 EGI Gearbox Differences ??
Post by: shaunwil on November 20, 2011, 12:15:11 PM
I\'m also wondering if I have a S5 EGi gearbox because I don\'t have the LH vent (above the starter). It all fit fine so not too worried about it !

Shaun
Title: S4 & S5 EGI Gearbox Differences ??
Post by: shaunwil on November 20, 2011, 02:38:09 PM
Found my clutch slave rebuild kit I\'d lost (found it in my jacket :Giggle ) . Just need the bolt now.

Shaun