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;

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 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 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

BST = Torsen

Gearbox oil

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

See also

• Gearbox Reversing Switch
• http://forums.seloc.org/viewthread.php?tid=96372

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 C/R code of S1 111s and standard S2 , but the ratios are off a S2 111S.

• http://www.quaife.co.uk/LOTUS