What gearbox could I mate up to a 1977 Mazda 808?
Sir Zako Sixpence©
considering replacing the 4 speed manual, with a 5 speed.
She's got the 1300cc in it. Anyone know of what gearbox could fit in there?
I've been told that the old Celica boxes could be a go.
Any suggestions?
Regards,
Zako
Charlie
This is all from Spac on Ausrotary.com, he posted this a while ago as
general info for everyone. Quite possible you'll find it useful.
Charlie
Gearboxes
The Mazda RWD gearboxes can be broken down into four groups:
Early piston
Smooth case
RX-4 type
Clamshell
1. The Clamshell boxes were fitted to very early cars only. They can
easily be identified by their construction – the main casing is made
from two pieces, joined vertically. The bell-housing is removable, and
is held onto the case with SIX bolts. These gearboxes were fitted to
1500, R100 and 10A RX-3. The RX-3 has the usual twin dizzy top mounted
starter, but the R100 has a bottom mount starter, meaning there are
three different types of bell-housing available for these gearboxes
(including the piston one).
*Input and output shafts have few (14?) coarse splines.
*Many 1500s were column shift.
*Shifter length (reward distance from motor) varies between R100 and
RX-3.
*Early R100 boxes have a rough sand cast finish, particularly on the
extension housing, and also have needle roller bearings for the
tail-shaft.
The boxes are reasonably strong for their age. They are also helped by
the fact that they were never required to withstand anything more
powerful that a 10A. Abuse will result in any number of different
breakages occurring – jamming in gear, breaking input shafts, shearing
teeth off gears, and/or opening up the two halves of the case.
2. The Early piston boxes were fitted to all piston cars before the
first 323. These gearboxes can be identified by their small size,
external webbing, integral bell-housing and ‘sculptured’ shape. The
smaller engined cars (1300, 1300cc 808) have a smaller version compared
to the Capella, 929 and 1600cc 808 – most significantly the input shaft
is a smaller diameter, compared to the 22-spline shaft fitted to the
larger cars.
These gearboxes are the forerunners to the later Smooth case gearboxes
and as such do have some similarities. However, as these boxes are only
available in 4-speeds for the piston engines there is little interest in
them.
Behind standard piston engines, they will be strong enough for most
needs. Severe abuse usually results in a loud internal grinding noise
and replacement of the entire gearbox – nobody ever bothers to even have
a look at what broke…
3. Smooth Case. These were Mazda’s mainstay from the late 1970s into the
mid eighties, and so were fitted to RWD 323s, RWD 626s, 929Ls, HB
(“Cosmo”) 929s, 1st Generation RX-7s, 12A Turbos, non-turbo Series 4
RX-7s, and many vans and utes.
They can be identified obviously by their smooth case, and by their
integral bell-housing. Some later cars (most commonly FE powered 929s)
have a circumferential external rib around the bell-housing.
*323 boxes have a smaller diameter input shaft compared to others, which
all have the common 22-spline input shaft. This version is distinctive
due to its smaller bell-housing which has a raised section with a flat
top, where it bolts to the motor. These are available in both 4 and
5-speed versions. Notably the cases are different (due to the extra
length required for the 5th gear), making the 5-speed a difficult fit
into a factory fitted 4-speed 323. 808s have more mounting points, and
so are a much easier fit. For both cars, factory auto version will
easily accommodate the 5-speed gearbox.
*The S1 RX-7 gearbox is a direct swap for the earlier RX-4 / RX-5
gearbox, and all mounting points, shifter position etc are the same. The
rotary gearboxes can be identified by having a hole for the starter
motor to be fitted to (piston motors have the starter motor fitted to
the engine). All smooth case rotary gearboxes are 5-speed.
*S2, S3, S4 RX-7s have a remote shifter that places the shift lever
100mm further back compared to the S1 RX-7 gearbox. These are a
substantial update over the S1 boxes and are much stronger, although not
indestructible.
* The RWD 626 boxes and the later MA-powered 929 boxes are identical to
each other. These have the best ratios of any Mazda production gearbox.
They can be identified by the very short distance from the motor to the
gear lever – it is 100mm shorter than the S1 RX-7 gearbox, making it
200mm shorter than the S2 and later RX-7 boxes. Available in both 4 and
5-speed versions.
*The FE Smooth Case gearbox, as fitted to post 1983 929s is identified
by its larger bell-housing with a raised flat top section where it bolts
to the motor. Apparently these gearboxes received the same improvements
as the S2 and later RX-7 gearboxes. 5-speed only
*The van boxes are column shift, and generally have appalling ratios for
road car use. They have bell-housings the same as the car boxes (ie, to
suit TC,UC, D5, NA, VC, MA, and FE motors).
*The S3 and S4 NA boxes also have a unique output shaft size, which is
larger than the earlier gearobxes.
The front case/bell-housings are interchangeable between all gearboxes.
It is possible to put a RX-7 front case onto a 626 gearbox to make it
fit a rotary motor, or a FE case onto an RX-7 gearbox if a replacement
FE gearbox was not available. The 323 gearbox is the exception to this,
as it incredibly has a slightly different shape, so none of the bolts
line up if you attempt to bolt a 323 bell-housing onto a gearbox from a
larger car. It would also require a custom clutch plate (due to its
smaller input shaft, and smaller diameter shaft). The 323 also appears
to have a smaller bearing in the front case.
The extension housings are also interchangeable, meaning that on any
gearbox, you have the choice of four different shifter positions (626,
S1, S2 or S4 NA).
The Smooth case gearboxes are generally weak. The S1 RX-7 box in
particular has a (well deserved) reputation for breaking with very
little provocation. Breaking input shafts, output shafts, stripping
teeth off gears, breaking cases and jamming in gear are all common. The
piston gearboxes are no stronger, but are generally OK as they rarely
have to withstand as much power as the rotary gearboxes. Interestingly,
the ‘works’ racing gearboxes have much thicker cases, suggesting that
much of the strength issue is due to a weak, flexible casing.
4. The RX-4 style gear box is probably the most common gearbox used in
rotary Mazdas. From a basic design that first saw the light of day in
the early 1970s, it has been upgraded and modified ever since and was
even used in the S6 RX-7.
These gearboxes can be identified by their rectangular external webbing,
removable bell-housing (8-bolts) and flat aluminium ‘sump’, which is
attached to the gearbox by a large number (14?) 6mm bolts. This style
can be broken down into sub-categories:
*Twin dizzy or Straight type. This model was fitted to early RX-2s and
early twin dizzy RX-4s. They can be identified by looking at the
machined flat for the gearbox rubber mount – for these gearboxes only,
the flat is parallel to the gearboxes’ sump. This means the gearbox sits
in the car in a totally upright position. There is only one type of
bell-housing to suit these gearboxes – the twin distributor top-mount
starter motor one.
Ratios are very poor, with a very low ratio 1st gear, and a large gap
between 2nd and 3rd gears.
These are a fairly strong gearbox, with jamming in gear (almost always
3rd gear) being the most common problem. Breaking synchro rings is not
unheard of.
*Early single dizzy or Twisted type. This name is slightly misleading,
as these gearboxes were not only fitted to single distributor motors.
These look very similar to the twin dizzy gearboxes, however the main
case does not sit upright in the car – they are twisted over slightly
(~15deg) to make room for the rotary bottom mount starter motor. As
such, the gearbox mount and the sump are not parallel to each other. In
detail:
a) Late RX-4 Twin dizzy. Later 12A twin dizzy RX-4s have the updated
bottom mounted starter motor. Notably, the starter is different to the
later single dizzy bottom mount starter motors, which have a smaller
body – you can see this by the large (~80mm) hole in the bell-housing.
These bell-housings are the only easy way to fit a 5-speed behind a twin
dizzy motor – more on this later.
The ratios in these gearboxes are the best ratios Mazda EVER offered in
a factory rotary gearbox. They are also very strong, being able to
withstand over 300 horse-power – beyond this power level, the gear-box
case becomes the weak point as it tends to expand and allow the shafts
to move relative to each other, which then results is broken shafts
and/or stripped gears. Wayne Dyson’s 9.7 second 500+hp RX-3 used an
internally standard RX-4 gearbox that was substantially braced
externally with a “full metal jacket” – a steel sump (rather than
alloy), and some hefty steel strapping running around the outside of the
case.
The most common failure with these gearboxes is jamming in 3rd gear when
they are worn. The more power being fed through them, and the more worn
they are, the more likely it is that they will jam in gear.
b) RX-4 Single Dizzy. The actual gearbox is identical to the later Twin
Dizzy “twisted” gearbox, but the bell-housing was changed to suit the
single dizzy motors’ new bolt pattern, and to suit the inexplicably
different starter motor. These bell-housing can be identified by their
smaller starter motor hole – it is roughly 55mm in diameter.
c) RX-5. This box is essentially just a 5-speed version of the RX-4
gearbox, and as such, has the same strengths and weaknesses. The ratios,
however, reverted to the old top-mount twin dizzy ratios and as such are
appalling. Bell-housing is the same as single dizzy RX-4.
d) 121. Again just another revision of the theme – although obviously
fitted with a bell-housing to suit the piston motor. The piston
bell-housing can be identified by its lack of a hole for the starter
motor. These gearboxes have a shorter gear lever position (approx 100mm
further forward compared to the RX-5 gearbox. All previous RX-4 type
boxes have the same shifter position length as the RX-5). The 121 box is
blessed with the much better later RX-4 ratios. Changing the extension
housing to the RX-5’s item will create a “close ratio” RX-5 5-speed.
Notably, in both 5-speed boxes mentioned so far, 5th gear is removable,
and the RX-5’s 5th gear is a closer (less over-driven) gear than the
121’s. The “ultimate” all production Mazda gearbox would use a 121
gear-set, fitted with the RX-5’s 5th gear. Note that later 121s were
factory fitted with a 626 style Smooth Case gearbox.
e)TQX. This is a weird import-only gearbox that you may happen to
stumble across. Factory fitted to Jap market RX-5s, they are a 5-speed
manual gearbox, which also uses an automatic style torque converter. It
is very rare to find one that still has all of the torque converter
intact, however, some importers try to sell them as “RX-5 style”
gearboxes. They have a very short, very angled gear lever position, and
therefore will not easily bolt into anything without the torque
converter gear. The gearset however, can be transplanted into a RX-5 or
121 case. Ratios are the same as 121.
*Series 4 Style.
This is just a major update to the old style RX-4/5 gearbox. Still a
Twisted type box, but with a different twist compared to the earlier
versions. Visually they are similar to the older gearboxes, but with
some external clues:
*Remote shifters, similar to the S2/3 RX-7s. This puts the shift lever
roughly 140mm further rearward than the RX4/5 position.
*The word “Mazda” cast into the side of the gearbox, at the front.
*An extra switch that looks very similar to a reverse light switch. This
is for the factory ECU to detect 5th gear.
*The removable bell-housing is larger, and is much smoother compared to
the early versions. This is to accommodate the S4’s larger 9.5” diameter
clutch (as compared to 8.5” for all the early rotaries).
Internally, these gearboxes are much revised compared to the early
versions. The input shaft is larger at 23 splines (rather than 22) as is
the output shaft. The gears themselves are stronger, as are the
synchros. While much stronger than the earlier gearboxes, they do have a
unique problem with an internal nut coming loose and allowing the gears
to “float” on their shaft, resulting in only 4th gear providing drive.
The S5 style gearbox can be identified by its extra webbing, and
different gearbox mounting point. Where the S4 has a flat machined into
the extension housing and the rubber mount is held by two 8mm bolts (the
same as all other RWD Mazdas to that time), the S5 has two pairs of 8mm
bolts (ie 4 bolts in total) that are angled in.
These gearboxes were also fitted to the V6 powered 929s (manual
gearboxes of this type are import only, it seems), and many later model
vans and utes.
Bell-housing swapping.
All of the “RX-4 style” gearboxes have removable bell-housings, and as
such, any bell-housing can be bolted to any gearbox – with some
conditions!
Putting a twisted type bell-housing onto a straight type box will result
in the gear lever sticking out pointing greatly towards the passenger.
The gearbox mount will not sit parallel either, requiring some “creative
engineering” to make a workable gearbox mount. Obviously, the reverse
combination will result in the problems being reversed.
The S4 type box will also bolt to the early Twisted type bell-housing.
This combination results in the shift lever pointing towards the left,
although usually only slightly. The bigger problem is the gearbox mount
no-longer sits flat and will require thought. Notably, some S4 gearboxes
have 10 bolts to hold the bell-housing on – the extra two bolts (top
centre and bottom centre) can simply be ignored.
In all cases of swapping bell-housings, the flywheel and starter motor
must match the bell-housing used. When changing between the top-mount
and bottom mount starter twin dizzy bell-housings, the ring gear must be
swapped around as the chamfer on the teeth is on the opposite side of
the ring gear. Similarly, fitting the earlier twisted type BH to a S4
gearbox will need the earlier starter, flywheel and clutch to be used,
as the hole in the BH will not allow the starter to line up with the
outside of the ring gear.
Whenever fitting a S4 or later gearbox to any early motor, be aware that
the spigot bearings are different sizes (S4 is larger).
*The twisted type twin dizzy bell-housing. These rare bell-housings
allow a multitude of gearbox swaps onto twin distributor motors. RX-5
and 121 gearboxes are direct bolt-ons, S4 gearboxes are possible
(although the same problems are encountered as when using a twisted
single dizzy bell-housing to mount one of these gearboxes), and Supra
and Celica conversions are possible with the use of a readily available
adaptor plate.
Be aware that the starter motors are quite difficult to obtain, and are
only available from this model bell-housing and from the even rarer
bottom mount R100 clam-shell gearbox.
At a Glance.
1. All gearboxes have 22 fine spline input shafts, with the following
exceptions: Clam-shell (coarse spline), S4 and later (23 fine spline)
and the 1500cc and smaller engined cars (20? Fine spline).
2. All gearboxes have the same fine spline output shafts, with the
following exceptions: Clamshell (coarse) and S4 and later (larger).
(Note that the smaller cars are the same as the “norm” in this regard).
3. There are four common engine-to-shifter lengths. From shortest to
longest: Piston, early rotary (all before S2 RX-7), S2 & S3 RX-7, and
S4+ RX-7. (S6 RX-7 is ignored, because I don't know!)
4. There are two different types of shift lever – front slot and rear
slot. This refers to the location of the pivot pin in the top of the
gearbox. The general rule is that early 4-speeds have one type, and late
4-speeds and all 5-speeds the other. Be aware that fitting an early
4-speed shifter and shifter block (the alloy casing that bolts to top of
extension housing) to a 5-speed MAY result in not being able to access
5th or reverse gears.
5. There are at least three different shifter ball-lengths – this refers
to the distance between the spherical sections on the bottom of the
shift lever. Too short will result in frequent missed gears (sometimes a
total inability to engage any or all gears). Too long will result in the
gearbox jamming in gears.
****Update. The 5-speed MX-5 gearboxes are smooth-case type gearboxes.
Ratios are similar to both S1 and S2 RX-7, without being the same as
either . They also have the big power-train girdle, like a S6 RX-7, and
are therefore difficult to mount into earlier cars.
The 6-speed MX-5 gearboxes are an Aisin manufactured gearbox, which is
the same gearbox as fitted to the Lexus IS200, S15 200SX, and the new
RX-8. I do not yet have any info on ratios, mountings or input/output
shafts.
Sir Zako Sixpence©
"Charlie" <cdr...@bigpond.net.au> wrote in message
news:3F29D419...@bigpond.net.au...
> "Sir Zako SixpenceŠ" wrote:
> >
> > I just purchased a bargain of a car which I'm slowly restoring, and am
> > considering replacing the 4 speed manual, with a 5 speed.
> >
> > She's got the 1300cc in it. Anyone know of what gearbox could fit in
there?
> > I've been told that the old Celica boxes could be a go.
> >
> > Any suggestions?
>
> This is all from Spac on Ausrotary.com, he posted this a while ago as
> general info for everyone. Quite possible you'll find it useful.
>
> Charlie
>
>
>
> Gearboxes
>
>
> The Mazda RWD gearboxes can be broken down into four groups:
> Early piston
> Smooth case
> RX-4 type
> Clamshell
>
> 1. The Clamshell boxes were fitted to very early cars only. They can
> easily be identified by their construction - the main casing is made
> from two pieces, joined vertically. The bell-housing is removable, and
> is held onto the case with SIX bolts. These gearboxes were fitted to
> 1500, R100 and 10A RX-3. The RX-3 has the usual twin dizzy top mounted
> starter, but the R100 has a bottom mount starter, meaning there are
> three different types of bell-housing available for these gearboxes
> (including the piston one).
> *Input and output shafts have few (14?) coarse splines.
> *Many 1500s were column shift.
> *Shifter length (reward distance from motor) varies between R100 and
> RX-3.
> *Early R100 boxes have a rough sand cast finish, particularly on the
> extension housing, and also have needle roller bearings for the
> tail-shaft.
>
> The boxes are reasonably strong for their age. They are also helped by
> the fact that they were never required to withstand anything more
> powerful that a 10A. Abuse will result in any number of different
> breakages occurring - jamming in gear, breaking input shafts, shearing
> teeth off gears, and/or opening up the two halves of the case.
>
>
> 2. The Early piston boxes were fitted to all piston cars before the
> first 323. These gearboxes can be identified by their small size,
> external webbing, integral bell-housing and 'sculptured' shape. The
> smaller engined cars (1300, 1300cc 808) have a smaller version compared
> to the Capella, 929 and 1600cc 808 - most significantly the input shaft
> is a smaller diameter, compared to the 22-spline shaft fitted to the
> larger cars.
> These gearboxes are the forerunners to the later Smooth case gearboxes
> and as such do have some similarities. However, as these boxes are only
> available in 4-speeds for the piston engines there is little interest in
> them.
> Behind standard piston engines, they will be strong enough for most
> needs. Severe abuse usually results in a loud internal grinding noise
> and replacement of the entire gearbox - nobody ever bothers to even have
> a look at what broke.
> gear lever - it is 100mm shorter than the S1 RX-7 gearbox, making it
> machined flat for the gearbox rubber mount - for these gearboxes only,
> the flat is parallel to the gearboxes' sump. This means the gearbox sits
> in the car in a totally upright position. There is only one type of
> bell-housing to suit these gearboxes - the twin distributor top-mount
> starter motor one.
> Ratios are very poor, with a very low ratio 1st gear, and a large gap
> between 2nd and 3rd gears.
> These are a fairly strong gearbox, with jamming in gear (almost always
> 3rd gear) being the most common problem. Breaking synchro rings is not
> unheard of.
>
> *Early single dizzy or Twisted type. This name is slightly misleading,
> as these gearboxes were not only fitted to single distributor motors.
> These look very similar to the twin dizzy gearboxes, however the main
> case does not sit upright in the car - they are twisted over slightly
> (~15deg) to make room for the rotary bottom mount starter motor. As
> such, the gearbox mount and the sump are not parallel to each other. In
> detail:
>
> a) Late RX-4 Twin dizzy. Later 12A twin dizzy RX-4s have the updated
> bottom mounted starter motor. Notably, the starter is different to the
> later single dizzy bottom mount starter motors, which have a smaller
> body - you can see this by the large (~80mm) hole in the bell-housing.
> These bell-housings are the only easy way to fit a 5-speed behind a twin
> dizzy motor - more on this later.
> The ratios in these gearboxes are the best ratios Mazda EVER offered in
> a factory rotary gearbox. They are also very strong, being able to
> withstand over 300 horse-power - beyond this power level, the gear-box
> case becomes the weak point as it tends to expand and allow the shafts
> to move relative to each other, which then results is broken shafts
> and/or stripped gears. Wayne Dyson's 9.7 second 500+hp RX-3 used an
> internally standard RX-4 gearbox that was substantially braced
> externally with a "full metal jacket" - a steel sump (rather than
> alloy), and some hefty steel strapping running around the outside of the
> case.
> The most common failure with these gearboxes is jamming in 3rd gear when
> they are worn. The more power being fed through them, and the more worn
> they are, the more likely it is that they will jam in gear.
>
> b) RX-4 Single Dizzy. The actual gearbox is identical to the later Twin
> Dizzy "twisted" gearbox, but the bell-housing was changed to suit the
> single dizzy motors' new bolt pattern, and to suit the inexplicably
> different starter motor. These bell-housing can be identified by their
> smaller starter motor hole - it is roughly 55mm in diameter.
>
> c) RX-5. This box is essentially just a 5-speed version of the RX-4
> gearbox, and as such, has the same strengths and weaknesses. The ratios,
> however, reverted to the old top-mount twin dizzy ratios and as such are
> appalling. Bell-housing is the same as single dizzy RX-4.
>
> d) 121. Again just another revision of the theme - although obviously
> such, any bell-housing can be bolted to any gearbox - with some
> conditions!
>
> Putting a twisted type bell-housing onto a straight type box will result
> in the gear lever sticking out pointing greatly towards the passenger.
> The gearbox mount will not sit parallel either, requiring some "creative
> engineering" to make a workable gearbox mount. Obviously, the reverse
> combination will result in the problems being reversed.
>
> The S4 type box will also bolt to the early Twisted type bell-housing.
> This combination results in the shift lever pointing towards the left,
> although usually only slightly. The bigger problem is the gearbox mount
> no-longer sits flat and will require thought. Notably, some S4 gearboxes
> have 10 bolts to hold the bell-housing on - the extra two bolts (top
> 4. There are two different types of shift lever - front slot and rear
> slot. This refers to the location of the pivot pin in the top of the
> gearbox. The general rule is that early 4-speeds have one type, and late
> 4-speeds and all 5-speeds the other. Be aware that fitting an early
> 4-speed shifter and shifter block (the alloy casing that bolts to top of
> extension housing) to a 5-speed MAY result in not being able to access
> 5th or reverse gears.
> 5. There are at least three different shifter ball-lengths - this refers
Ian
Mazda's) head!
"Sir Zako Sixpence©" <youn...@yahoo.com> wrote in message
news:NlqWa.4478$bo1....@news-server.bigpond.net.au...
> Much appreciated! Thank you
>
Sir Zako Sixpence©
Jon Hedge
> sorry dude :-)
>
>
Hey, think of all the people out there who don't have access to previous
posts! "sorry dude" doesn't really mean a thing. Include the previous post
=oP
~jon
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