MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB GT V8 Factory Originals Technical - Auto B

I have a 70 Automatic B with a dying but not yet dead 4 potter and am keen to replace with a Rover 3.5. I can get hold of one of two motors from Range Rovers locally, can anyone tell me if the original MGB Trans will fit the 3.5 motor and would the auto rear axle require any modification/replacement to cope with the extra power. I have every intention of replacing the auto with a manual as I prefer a manual but are difficult if not imposible to find in my location.
K Woolman

The automatic in the B is a Borg-Warner similar but not identical to the ones used by Rover behind the V8. If you want to keep you B an automatic, you should try to acquire the transmission and engine as a unit. It will be easier than trying to upgrade the tranny you've got and then adapt it to the V8. Your rear axle is probably a 3.70 that may be too low a ratio to make use of the torque of the V8. I would suggest either a 3.07 gear set, but with the torque multplication of the troque converter of the automatic, you could make use of an axle from a Falcon or other V8 powered automtatic car with a 2.73 ratio or something like that.
John Perkins

You can get by with the MGB axle for quite a long time behind a V8 so the transmission is the concern. There are several better choices than the stock manual transmission however such as the T-5. If you do a search for threads addressing "transmission" you should come up with a great deal of relevant information.

Jim
Jim Blackwood

K Woolman,
The auto trans for the B was originally a Borg Warner type 35 and will not last long behind the torque produced by the V8.
The rear ratio is as mentioned above suitable for the 4 banger but is too "short" and not stroing enough for the V8.
A suggestion is the BW T5 fitted to the V6 Commodore which is essentially a overdrive attached to the updated and standard BW 4 speed.

Cheers , Pete.
Peter Thomas

This thread was discussed between 13/06/2005 and 14/06/2005

MG MGB GT V8 Factory Originals Technical index

This thread is from the archive. The Live MG MGB GT V8 Factory Originals Technical BBS is active now.