Putting a Getrag 265 gearbox into a Tiger
I found my tiger under a mango tree and bought it for $120 without engine or
gearbox. An old 302 was easy to find, even in Zambia, but a 4-speed
toploader was a problem. When I spoke to Alf Dragan in South Africa, he told
me that all the cobra and tiger racers in South Africa were using a very
strong Getrag gearbox that was found in big BMWs in the early 80s and in
some Opels. After more investigation I found that this was the Getrag 265
gearbox and it was also used in the Jaguar XJS V12, some Maseratis but
mostly in big BMWs. Vicarage Jaguar uses one in their racing E-type and
Metric Mechanic makes special versions for racing BMWs
(www.metricmechanic.com.)
These gearboxes are very easy to find and very cheap since they always
outlive their host cars. In a web search of the USA I found thousands of
them for under $100. Look for them in 6 cyl BMWs: M3 and big six '80 to
'82, 528e '82, 535,635,745 in '85. They have removable bell housings which
is why they are easy to adapt. They might have casting numbers starting 262
but you can tell it is a 265 if it has a 97mm long center casing which is
sand cast so it looks a bit duller than the front and back castings. They
can take 350 ft/lbs of torque in standard form or 400 ft/lbs with the Metric
Mechanic upgrades.
You can get new aluminium bell housings made to fit these gearboxes onto a
SBF or SBC for $200 in South Africa. I only found this out after I had TIG
welded the back of the Getrag bellhousing onto a Ford aluminium bellhousing.
The ratios of the 265 are well suited to the tiger at: 3.82, 2.20, 1.39,
1.00, 0.81
I am using the less common Opel 3.0 litre 265 gearbox as it has a splined
output shaft.
The BMW boxes have a flanged output so require a propshaft with a sliding
section.
I recently fitted my prototype bellhousing plus 265 Getrag to my 302
block so I can tell you these distances. These are for the Opel box and
may be a little different for the BMW or Jaguar versions:
block to shift lever 645mm (and 675mm block to output shaft)
engine mount stud to shift lever 965mm
block to side gearbox mounts 390mm (on the side, 1/4 way up)
block to rear-bottom gearbox mount 550mm
(there are two different mounting positions, probably to match different
cars.)
The shift lever comes up in the center of the transmission tunnel, about 3
inches in front of the cross member. I removed a thick rubber spacer from
the shifter mount in order to get the shifter further forward. You do have
to cut a new hole for the shifter but it is in a very nice position. Other
useful info is that the 265s have either a Ford or a Chevy input clutch
spline (so I am using an out of the box Centerforce clutch disk and pressure
plate.)
I made up a simple bracket that bolts to the chassis and holds the rear
engine/gearbox mount. It uses the rear-bottom gearbox mount. My small 3/4
inch Nissan slave cylinder bolts onto two heavy aluminium lugs that I welded
onto the bellhousing. I will adjust the pedal pressure by changing the
length of the fork or if I have to Ill sleeve the master cylinder. The fork
is a slightly modified fork from the donor Opel. My propshaft is a Landrover
rear propshaft with the front U-joint and splined section from the donor
Opel.
I havent driven the car yet and probably wont for a while since Ive moved
myself to Sri Lanka and the tiger to a restorer friend in Zimbabwe. Once I
do drive the car, I will talk to a BMW agent or Metric Mechanic about an
appropriate speedo drive gear for the gearbox or I may just put a small
reduction box at the speedometer.
I would love to hear from anyone else who tries this. My car is in pieces so
if you want any of the fabricated pieces copied let me know. From what I
have read and heard, this is a stronger gearbox than the T5 and it has
ratios that are better suited to the tiger. It also puts the gear stick in a
better position without having to cut the cross member or find the rare AMC
tail housing. Another big bonus is the cost. If you buy the bell housing for
$200 and the gearbox for $50 (they are out there, I kid you not!) you can
have a strong overdrive five-speed transmission for around $300 and a bit of
work.
I might put together a few kits if there is enough demand. I will definitely
look into supplying these bell housings to the Ford/Chevy community in the
USA as I feel it could be a real money-spinner. I will attach the only
picture I have of the setup for those of you whod like to try it. It will
be removed by the list server but Steve can put the picture with this
description onto www.TigersUnited.com. Good luck and keep me posted if you
try this in your tiger.
derekw@sltnet.lk, derekrwhite@yahoo.com
[demime 0.97c removed an attachment of type image/jpeg which had a name of
getrag265a.jpg]
|