E36 318is - Gearbox Question.

[GreatGranny]

I have a 318is which I bought (probably foolishly) to do a 420 mile per week commute.

Its been ultra reliable and on the whole is a comfortable place to be with full leather, climate, decent stereo etc..

The only gripe is that it is geared pretty short and at 65mph its doing 3k rpm.

Economy is working out at about 35-36 mpg but I do drive it gently.

I would like to keep it so what's the alternatives to making it longer geared?

Are there any 6 speed boxes that will fit or are any of the other engines longer geared?

Costs is an issue so it will have to be an economical thing to do. If not I may have to change it.

Thanks in advance.

PS Just found the gear ratios for the E36 and all the ratios are the same with 5th being 1.00 even the 6 cyclinder models. However the final drives differ. Don't fully understand how it works, does lowering the final drive raise the gearing or is the opposite?

Edited by GreatGranny on Monday 1st November 09:50

[E30M3SE]

You car runs a 3.38.

323-28's ran 2.93, 325 and 3.0 M3 3.15 and the M3 Evo ran 3.23, any of these will do what you want.

If your car has a LSD you want to replace like for like.

[GreatGranny]

Thanks E30M3SE.

No idea if mine has as LSD. How would I check (apart from booting it out of a wet roundabout)?

[E30M3SE]

Jack up back of car until both wheels are off the ground, turn one wheel, if the other turns in the same direction you have a LSD, or, just jack up one side of the rear and try to turn the wheel if you can turn the wheel it does not have a LSD

[GreatGranny]

Thanks for info.

I'm going to price up a different diff. Non LSDs are going for £50-90 on Ebay.

Are they pretty straight forward to swap.

I'll have access to jack, axle stands and decent tools from my S in L's hubby.

H