SUPRA 5 SPEED MANUAL GEARBOX COMVERSION
for VOLVO 200/700 series B21/B23/B230 engine
by Anthony Hyde, Canberra, AUSTRALIA. Anthony.Hyde@anu.edu.au
The alloy cased Toyota Supra 5 speed conversion is manufactured by Dellow
Automotive in Sydney, Australia. Dellow has over 20 years experience in
conversions, and offers Volvo owners kit #S-V to suit the popular tilted red
engined B21/B23/B230 Turbo or normally aspirated version. The kit offers converters
a flying head start with the number one requirement a bellhousing, plus a speedo
cable, clutch disc & related parts. Note the kit does not include a modified
crossmember, g/box to trans mount, or modified tailshaft, this is up to you.
For 140 series owners with an upright B18/B20, a Toyota Celica 5 speed steel
case kit is available. As can be seen in the pictures, the box is of very neat
design, which by comparison makes the M46 seem pretty industrial.
Rear: Volvo M46 with Overdrive
Front: Alloy cased Supra W55 with Dellow
The camera lens has distorted the length comparison.
Overall length is within 10 mm. Shifter position is within 5 mm.
The 240/760/740 Volvo turbos use the M46, an in-house 4 speed design coupled
to a UK designed Laycock overdrive for 5th reportably good for near
225 hp. This two-section transmission is fine until the complicated ODrive
wears, causes trouble, and is very expensive to replace, or repair perfectly.
Owners face high cost again when it's time to replace the gearbox and this is
where I drew the line. I wanted 5 real gears based on a strong design at a reasonable
Volvo manufactured a 5 speed M47 v.I&II, but for performance driving with
a turbo engine its just not strong enough, one problem area being the
low friction synchros. Strong 5 speed options to suit a 4 cylinder are Supra,
Getrag or Volvo M90. The Supra is readily available with suitable ratios and
can handle 300+hp, the Getrag M50/51 or 262/265 found in BMWs are expensive
(bellhousing from SAM in Sweden), and the M90 only a dream outside Europe.
M46 + Overdrive
Supra W58 (US/Can)
1st - 3.71:1 or 4.03:1
1st - 3.57:1
1st - 3.95:1
1st - 3.28:1
2nd - 2.16:1
2nd - 2.06:1
2nd - 2.14:1
2nd - 1.89:1
3rd - 1.37:1
3rd - 1.38:1
3rd - 1.27:1
3rd - 1.27:1
4th - 1.00:1
4th - 1.00:1
4th - 1.00:1
4th - 1.00:1
5th - 0.79:1
5th - 0.85:1
5th - 0.85:1
5th - 0.78:1
Pros: choice of gearboxes (hence ratios) depending on availability, perfect
gear stick position, light weight, kit includes speedo cable, based on a strong
Cons: Lot of effort required to modify crossmember & g/box to transmission
ROAD TEST: W55
Supra shift quality is good and direct, but does not push into gear as easily
as a good M46. Gear ratio spread is very progressive through the range, better
than the M46, with less time taken for third gear to rev out! Shifter throw
is 5 mm less at either end of say 1st to 2nd so 10 mm
less gearshift travel in total. As expected, a few top gear resonances compared
to the M46s isolated Laycock overdrive system. The Supra W55 5th gear
reduction of 0.85:1 is not as low as the Volvo overdrive's 0.79 which is an
advantage in flowing traffic as your not continually catching up with the car
in front. The 0.85:1 reduction also offers improved hill climbing and top gear
Interested in the conversion detail, please read
Ultimately the Supra W55 was my choice for fitment into a sporty 244 with a
94 B230FT turbo engine, replacing a M46+OD. For Australian buyers, Dellow can
supply a 2nd hand serviced box as well, which they purchase in large numbers
from Japan. A Supra tailshaft yoke is extra. Dimensions for the Supra are very
similar to the M46/OD with overall length being only 10 mm shorter. The box
fits inside the 240 chassis tunnel with ease, with the shifter position in the
tunnel hole being perfect, much joy there. Specify the 20 1/2" shifter position.
The gearstick has a well executed dog leg angle for an ideal position. The alloy
cased Supra weighs 33 kg + 5 kg for bellhousing etc, and is lighter than an
equivalent cast-iron cased M46+OD by 7 kg (15.4 lb), representing a weight saving
of 18.5%. This difference would not be as great with the later 1985-on alloy
case M46+OD Type P on turbo models. There are no markings on the
gearbox so its difficult to establish you have the right model other than
referring to the details on the receipt.
Overall the Dellow kit is a good product, especially the bellhousing, all well
thought-out and made. From a precision perspective, the important 'locating
dowel fits were spot-on for the bellhousing to engine and opposite bellhousing
to gearbox. It pays to trial fit every mating component you can in advance,
so allow time for this. I found plenty of hand filing was required to fit the
Volvo rubber shift-fork-boot and also the hydraulic clutch slave cylinder, memo
to Dellow. The yellow foam Volvo sound insulator saddle can be used again and
fits neatly around the g/box & tunnel. For markets that use a clutch cable,
the setup can be adapted. A custom 9" clutch plate is part of the kit, of good
quality and made by Australian manufacturer PBR. If you transmit a lot of torque
perhaps Dellow can supply a heavy-duty version. Note: 84-on turbo models use
a 9" clutch with a stepped flywheel, with earlier turbo and normally aspirated
I chose to use the genuine Volvo shift-fork in preference to the unit supplied,
which required hand filing of only 0.75 mm off each two legs to fit the carrier.
The supplied ball pivot was reduced in diameter to suit the shift-fork. The
supplied carrier & thrust bearing are of heavy-duty design and should be
long lasting compared to the less durable Volvo unit. The flywheel centre bearing
is replaced by an oil impregnated sintered-bronze bush, or spigot, pressed into
a steel shell which is specially made to suit the conversion. The speedo cable
is well made but too long for a 240. I have detailed to Dellow a few refinements
to enhance the conversion.
Crossmember and Gearbox mount
The most challenging task was modifying the Volvo transmission crossmember
and fabricating a gearbox mount to fit. There are tight space limitations because
the end of the g/box is near the crossmember and every piece requiring fabrication
has an angle on it.
It should be noted the Volvo engine & gearbox sit in a cradle with three
mounts inclined to one other, with the rear transmission mount inclined close
to 32 deg from the vertical. By comparison, the standard Supra mount is a straight
up and down affair which in my opinion does not suit the inclined Volvo setup.
This is the reason for the extra work.
As usual, half the battle is working out what you want and then making thin
alloy sheet mock-ups to get sizes and angles right. First step was to build
a trick angled bracket from the g/box to the topside of a Volvo transmission
mount (heavy duty B30). Next the crossmember adaptation that now attaches to
the rearward factory chassis holes (like auto model) being better for weight
The front section of the Volvo two-piece shaft requires adapting, and its
worth noting the following: - Volvo tailshafts come in two diameters 1 3/4"&
2", - depending on model have different front lengths, - Supra uses a sliding
spline affair vs the Volvo's fixed 4 bolt flanges. Two new yokes are required
to fit the front section. 1) Supra splined gearbox yoke, and 2) matching weld-yoke,
combined with a matching universal joint.
Dellow sell a Supra yoke with Ø25.4 mm (1") uni sizing, which is in
between Volvo sizes of Ø23.8 mm (15/16") or 27 mm (1 1/16"). My original
M46 front shaft was too short in length so I converted to a longer and larger
2' dia shaft off an auto 240 series. In Australia, the Hardy Spicer #17R-26-330
weld-yoke has a 1" uni and suits a 2" tube. From metal disc to centre of weld-yoke
I chose length 416 mm. Adapting tailshafts has its problems even with perfect
phasing. Old shafts can give mixed results for various reasons, so find the
newest you can. Balancing is mandatory. A one-piece shaft is an alternative
but the diff angle could require modification upward.
After a few months testing of the conversion, Im happy with the result.
The fitment has taken a lot of effort and free hobby time, and when it works
properly the pain is quickly forgotten. With conversions there is usually something
to sort out at the end, in this case the tailshaft. The gearstick position makes
shifting into all 5 gears a pleasure.
- Anthony Hyde
For conversion information contact:
Dellow Automotive &emdash; 37 Daisy St, Revesby, Sydney AUSTRALIA
Mail to: PO Box 43, Revesby North, NSW 2212 Australia
Ph +61-2-9774 4419, Fax +61-2-9774 3873