The M-46 is normally mated to an engine that is
"tilted" so to mate this gear box to an engine that is "upright" requires a
"special" bellhousing. You can either cut up the M-46 bell housing and then weld
it back together (actually more work than it first appears because of the clutch
"linkage" and the fact that everything has to be straight) or find a very
special bellhousing that Volvo made that does the same thing. The special bell
housing ;made by Volvo will cost maybe $350 to $450 when you can find
one... I tried to track the bell housing number down to find out what it was
originally installed on with the help of a very patient and sympathetic parts
man at Volvo but to no avail. At any rate, once you have the bell housing
problem solved then you need to shorten the gearshift level extension (about 4"
as I recall on my car), change the cable operated M-46 to a hydraulic system,
make or get a different clutch/throwout bearing release arm, Change the
clutch disc if the splines don't match your existing gearbox, relocate the arm
pivot, make or modify the transmission mount on the Marcos, and finally, shorten
the driveshaft approximately 1". Other than that, the installation is a
"slam dunk". On the more positive side you will have a slightly stronger
transmission/overdrive unit that you can still get parts for without a lot of
hassle. If anyone is serious about doing the conversion you can contact me
directly and I can give you a little more detail and share some pictures of my
installation. I have a 1966 Marcos 1800 GT so I have the 4 cylinder Volvo... I am not sure if everything I have said
applies equally to the 6 cylinder engine but I think it
does.
Mike Denman
Chassis # 4079
----- Original Message -----
From: Donny LangSent: Friday, February 06, 2004 5:12 PMSubject: [MarcosManiacs] Volvo overdrive 4 spd boxIs anyone interested in a Volvo M46 overdrive gearbox? I was at a
local salvage yard which is getting ready to crush a 1980 Volvo (4
cylinder) with 78,000 miles. They want $300.00 for the gearbox
complete from bellhousing to driveshaft flange, including shifter w/
overdrive switch. I don't know if this box fits any of the Volvo-
powered Marcos cars, but I thought I would bring this to the groups
attention in light of all the recent rear axle/transmission
questions. This message is not intended to be an advertisement, but
only to assist group members in finding a solution to some issues
recently raised. Reply or contact me offline so I can relay
information to you. I think it may only be around a few more days.
Donny Lang