Rover PG1 gearbox

Various Rover PG1 gearboxes have been used in the K Series powered Lotus Elise and the only way to identify them is from the serial number (somewhere) on the housing;

C6BP.... Standard box for Elise Mk1 and MGF

C4BP.... MGF VVC box (as standard but final drive 4.2)

B4BP.... Lotus CR box, Elise Mk1 111s, Elise Mk1 Sport 135 + Elise Mk2 standard box

B4BPU... Exige S1 (uprated)

B4BPQ... Exige S1 with LSD

G6BP.... Elise S2 111S

Gearbox Codes

The first letter is the gearset

c / 3.166 / 1.842 / 1.308 / 1.033 / 0.765

s / 3.250 / 1.894 / 1.222 / 0.848 / 0.649

b / 2.923 / 1.750 / 1.308 / 1.033 / 0.848

k / 2.923 / 1.750 / 1.222 / 0.935 / 0.765

m / 3.166 / 1.842 / 1.222 / 0.848 / 0.649

v / 3.250 / 1.894 / 1.222 / 0.935 / 0.765

t / 3.250 / 1.894 / 1.222 / 0.935 / 0.714

r / 3.250 / 1.894 / 1.308 / 1.033 / 0.765

w / 3.166 / 1.842 / 1.308 / 1.033 / 0.714

l / 2.923 / 1.750 / 1.222 / 0.848 / 0.649

g / 3.250 / 1.894 / 1.308 / 1.033 / 0.849

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

4 = 4.200 (15/63)

5 = 4.062 (16/65)

6 = 3.937 (16/63)

7 = 3.647 (17/62)

The right hand letters are the diff

BP = Open

BPQ = LSD

Gearbox Application Table

Car	PG1	1	2	3	4	5	Final
S1 "standard"	C6BP	3.167	1.842	1.307	1.033	0.765	3.938
S1 111S & S2 "c/r"	B4BP	2.923	1.750	1.307	1.033	0.848	4.200
MGF vvc	C4BP	3.167	1.842	1.307	1.033	0.765	4.200
S2 111S "long"	G6BP	3.250	1.895	1.308	1.033	0.848	3.937
Eliseparts		3.167	1.842	1.410	1.100	0.910	3.938
Suggested Ideal	*6BP	2.923	1.750	1.307	1.033	0.765	3.938
Exige S1 uprated	B4BPU	2.923	1.750	1.307	1.033	0.848	4.200
Exige S1 with LSD	B4BPQ	2.923	1.750	1.307	1.033	0.848	4.200

Gearbox oil

• Texaco MT94
• Castrol TAF-X
• Castrol SMX-S

Other sources of information

Quaife

ATB DIFFERENTIAL