Rover PG1 gearbox

The Rover PG1 gearbox fitted to the K series Elise, was manufactured by Powertrain Limited (who have now ceased trading), is a five-speed constant mesh gearbox, which employs helical gears for speed transmission and final drive. The transmission castings are full aluminium construction and all other components optimised for improved weight (36kg dry). The gearbox can be supplied with either a standard open differential or a Limited Slip Differential, presently Torsen.

Due to the modular design of the gearbox various final drive ratio and 1st to 5th gear ratio combinations have been used. Including both present and past an overall total of 21 ratio combinations, 5 speedometer gear ratios; and 7 clutch levers designs for both hydraulic and cable operation can be called on to ensure the customers requirements are met.

Gearbox type

Series number location on the bell housing

Identification is via the serial number on the bell housing housing;

Gearbox Application Table

Gearbox Code	1	2	3	4	5	Final Drive	Used In
G6BP	3.250	1.895	1.308	1.033	0.848	3.938	S2 111S (WR "long" box)
C4BP	3.167	1.842	1.308	1.033	0.765	4.200	MGF VVC (as standard but final drive 4.2)
C6BP	3.167	1.842	1.308	1.033	0.765	3.938	Elise S1 standard and MGF
B4BP	2.923	1.750	1.308	1.033	0.848	4.200	S1 111S & S1 Sports 135 & S2 135R & S2 standard (CR Box)
B4BPU	2.923	1.750	1.308	1.033	0.848	4.200	Exige S1 uprated (CR Box)
B4BPQ	2.923	1.750	1.308	1.033	0.848	4.200	Exige S1 with LSD (CR Box)
B6BST	2.923	1.750	1.308	1.033	0.848	3.938	Rover "BRM" 200 - CR box with std final drive & torsen LSD
340R UCR	3.0	1.937	1.556	1.273	1.043	3.92	340R LOTAC05255 Conversion
NA	3.167	1.842	1.410	1.100	0.909	3.938	Eliseparts

Gearbox Codes

The first letter is the gearset

Letter	1	2	3	4	5
b	2.923	1.750	1.308	1.033	0.848
c	3.167	1.842	1.308	1.033	0.765
g	3.250	1.895	1.308	1.033	0.848
k	2.923	1.750	1.222	0.935	0.765
l	2.923	1.750	1.222	0.848	0.649
m	3.167	1.842	1.222	0.848	0.649
r	3.250	1.895	1.308	1.033	0.765
s	3.250	1.895	1.222	0.848	0.649
t	3.250	1.895	1.222	0.935	0.714
v	3.250	1.895	1.222	0.935	0.765
w	3.167	1.842	1.308	1.033	0.714

The number that follows the gear set number is the Final drive ratio

4 = 4.200 (15/63)

5 = 4.062 (16/65)

6 = 3.938 (16/63)

7 = 3.647 (17/62)

The right hand letters are the diff

BP = Open

BPQ = Quaife LSD

BST = Torsen

See also

• Gearbox Reversing Switch
• Gearbox oil
• http://forums.seloc.org/t/96372
• http://forums.seloc.org/t/110925

External links

• http://www.gearboxman.co.uk
• http://www.powertrainltd.com/brochure/pt_brochure_product.pdf

  WARNING - The Lotus line is wrong on the Powertrain brochure, as it has the B4 CR code but the G6 WR ratios

• http://www.quaife.co.uk/LOTUS
• http://arc.seloc.org/viewthread.php?tid=173780 Gearbox drive program
• http://wiki.seloc.org/a/Shimming_the_Powertrain_PG1_gearbox
• http://www.rover-coupe.com/rcoc/index.php/downloads