What diff is in your M42 car?

[Nick_S]

Forgive the noob question...but how can I tell which I have?

[e30BMart]

Forgive the noob question...but how can I tell which I have?

I am not sure but I think LSD has an S on the bottom of it, and 3.73 stands for the number of wheel turns per driveshaft rotation? so count em.. Or,

Be a man! Smell it, spit on someone, swear then come back to us, you'll know.

[bmwm42]

lsd would have an s on top and also i would be marked s on the tag ie s4.10 or you could also jack up both wheels and spins them and they will both spin in the same directions and the ratio well that should be stamped on the tag.

[Nick_S]

I am not sure but I think LSD has an S on the bottom of it, and 3.73 stands for the number of wheel turns per driveshaft rotation? so count em.. Or,

Be a man! Smell it, spit on someone, swear then come back to us, you'll know.

Ha thanks for advice. I'll be changing the dif fluid this weekend so I'll check when I'm under there.

[thebutcher37]

NO LSD, but Im on a 4.10, thats what it came with and I heard 4.10 is a quick one.

[e30BMart]

NO LSD, but Im on a 4.10, thats what it came with and I heard 4.10 is a quick one.

Yeah, all m42 cars came stock with 4.10 some even came with lsd 4.10's. It is a short ratio diff but from there to saying it's a "quick" one is debatable :)

Since its open (I used to have one) sometimes you loose grip when accelerating and one wheel starts to spin freely and the other loses all power so you aren't going anywhere quick hehe... With lsd both wheels have grip and it is much harder to lose grip upon acceleration.

I know this because I ownes interwebz, and I also have an lsd now :)

[///digitalme]

4.10 open was useless to me lol.

[chrisbmx68]

4.10 medium case. good all around gearing for highway and around town.

[Reap3r]

3.73 Mid case LSD. Although I'm going to be turbo running it for the first time.

[e30_3I8I]

I have a 3.64 open .. its not that bad... I just don't really see 5th gear because 4th will take me up to 130+. oh and im around 3,200 rpm on the freeway cruising 70.

[mutty]

Moved from 4.10 to 3.05 and saved 20% on fuel. 150 miles per day round trip. could not be happier. Just have to adjust to the new feel.

[KenC]

What came with a 3.05?

If I were doing that much freeway driving I'd go that route too. I dig my 4.44 for the city 8).

[///digitalme]

^^^ I want to try 4.44, how does it compare to a 4.10??? I currently am running 3.91 vlsd and it's lovely to drive around town and freeway I get better mileage. But I want to run something quicker just to try it out for some time.

[Wanganstyle]

Moved from 4.10 to 3.05 and saved 20% on fuel. 150 miles per day round trip. could not be happier. Just have to adjust to the new feel.

Yay!!

3.07 actually;
z3 3.0 m54b30 year 2001/ 2002 w/ manual transmission

[flying_violin]

Pretty much like most people here, I run the 4.10 open because that is what was on the car when I bought it.