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MG MGF Technical - Final Drive Ratio's ?

Below is the Gear ratio's for both the standard and Close ratio PG1 box

(According to the B&G site)


* First 3.167 : 1
* Second 1.842 : 1
* Third 1.308 : 1
* Fourth 1.033 : 1
* Fifth 0.765 : 1

Close Ratio

* First 2.923 : 1
* Second 1.750 : 1
* Third 1.307 : 1
* Fourth 1.033 : 1
* Fifth 0.842 : 1

Does anyone know if the final drive gear is the same for both boxes ?

I have just nuked my existing box and want to fit a close ratio replacement but ideally fit the 5th gear out of my old standard box which would make the car still driveable and economical for when I am on the Motorway.


Stu Dickens

The final drive is in the diff - so you can choose what ever you like. In your case, you'd probably bring across the VVC FD, but you could source the MPi FD if you wanted slightly longer gearing (probably not enough to make a huge difference - and this is the kit that Techspeed have in their car)

Sorry to hear about the gearbox though. I did have a nasty feeling that it was on the point of imploding :o(
Rob Bell

VVC final drive ratio is 63:15 teeth, or 4.2:1.
MPi is 63:16 teeth, which works out at 3.937:1.
My edition of hte workshop manual lists the latter as 3.397:1. I suspect a typo given the number of teeth and that it sure doesn't feel like 3.3:1.
Paul Walbran

A typo Paul - you're right, it is 3.937:1

I've got a listing of the standard MGF gearbox ratios here:

Stu, might be worth looking out for limited slip differentials whilst your at it and while the gearbox and final drive are in pieces... :o)

Rover 220 Tomcat Torsen differentials often go for reasonable money... :o)
Rob Bell

Great idea on that LSD, have one fitted to mine :-) Come to think of it, our three midgets and the B as well. Only drawback is a suspicion of increased tyre wear as the tyres don't seem to last as long as the first set - after which was about when I got the slippy diff fitted. It could also be the nut behind the wheel.
Paul Walbran

This thread was discussed between 17/07/2006 and 18/07/2006

MG MGF Technical index

This thread is from the archive. The Live MG MGF Technical BBS is active now.