E30 Zone

hi, i want to change wat do people use.

also what diff has it got and what ratio.

also what would have shorter gear speeds, a diff with a final drive off 3.6 or 3.9.

my isnt locking up like before could it be rectified by oil change.

assuming it has it's original diff it will be a 3.64:1 LSD. If you were to fit a 3.91 from a later 325i you would get quicker acceleration but lower maximiun possible speeds in each gear.

If it's not locking it's probably worn out, PM Gareth for rebuild info and prices.

it does lock up. but nothing like my corolla coupe. probably just me. what oils should i use. fancy changing diff oil and gearbox oil just for service

Castrol SAF-XJ SAE 75W-140 is what BMW recommend for the LSD.

when you drop the oil, check for metallic particles. if it comes out all 'twinkly' then it's probably in a similar state to a lot of E30 diffs - fooked! not worth refilling and using as the damage will continue at a relentless pace. the particles come from the clutch plates and pressure plates as they wear through the hard friction coating and start to eat each other.

they can be saved and rebuilt though but don't leave it too long as the gears and bearings really dislike grinding paste in the oil

PM me if you want an idea on price.

regarding E30 diff locking, they aren't that 'tight' as standard and benefit from a 30° ramp angle modification to get them to 40% locking. some fresh clutch plates and 30° ramps transformed my diff