E36 M42 Diff Gear Swap

If it fits then Yes acceleration will be quicker but fuel consumption will also increase - less MPG.

Perhaps these numbers might help:

92 - E36 M42 1.8lit. 3.45:1 - 33 10 1 214 845

96 328i 3.07:1 - 33 10 1 214 631

96 328i 2.93:1 - 33 10 1 214 636

96 328i MALAYSIA ONLY - 3.91:1 - 33 10 1 428 387

So if you can get hold of a Malaysian 328i and steal the rear end .....?

However, I would imagine they will all fit but it appears the 3.9 wasn't an option in the US or Euroland.

Hugh Sir Hugh of Bognor

I'm not sure if the mounting is different so you might also need the subframe/diff carrier.

Parts list pictures look the same but then that's just a drawing although they are usually fairly accurate. Sir Hugh of Bognor

Yes. 325i was 3.15:1

Ar you sure it's 3.91:1? I don't think it is.

Yes, if it's IS 3.91:1. But at the expense of much higher rpms when cruising at speed and a lower top speed. It's not a good idea.

Wasn't the M42 engine an 1800cc ??????

No it isn't John - apparently the 3.91 was only a Malaysian option??? No doubt one could order it as an option for towing a caravan with the 1800 but I bet nobody did.

Especially at petrol prices as they are today and will be tomorrow and the day after..................... Sir Hugh of Bognor

Kevin,

Are you sure you need to do this? My '95 325i has whined under a light load since the day I got it used with ~60k miles. It now has more than twice that and I have done nothing to the rear end except change the gear oil.

As to your questions above, I cannot answer the first two questions. But if both 1 and 2 are correct, then the answer to 3 is Yes.

He might be please with the acceleration, but I doubt he will be pleased with the reduced top speed, increased fuel consumption, high rev's when cruising and reduced life expectancy of the engine.

If the car is auto then he may confuse the engine and gearbox management.