M50B25TU - G220 vs G240 + LSD

[N-Gen]

G240 boxes, from what I can see have different ratios than G220/250 boxes.

http://www.e30zone.net/e30zonewiki/index.php/Drivetrain

I found the same result on other sources as well. I'd rather change tranny than diff since it's limited slip and it wasn't cheap. Any idea where I can identify what the ratio on the diff is?

Edit: Went down to the garage, managed to find the engine number.

[franky2fingaz]

I'm not really sure, I must admit I'm no expert on E30s, most past builds were E12s and couple of rusty Bavarias, this is 1st E30 24v I'm putting together... ratios were usually on a metal tag on one of the diff's bolts, and most were missing. So, diffs and inspected , teeth counted and resealed... I'm doing an 89 M20 sedan, M50 single Vanos OBDI like yours, G250 trans and 2.93 LSD in the back, that should be a good daily I hope...

[N-Gen]

Well I think I could change the ring and pinion on the LSD and drop it to 3.25 or 2.93 since it's a cheap change. So if the G240 becomes problematic I could drop the G220 in and change the ring and pinion.

I think I'm safe to say I have options.

[franky2fingaz]

If you can get your hands on a G260, that has a something like a 0.82 5th gear, that will work better than the G250's 1:1 5th (with current diff), but you will need to do some homework to compensate a 10 degree extra tilt.. . plenty about it

[N-Gen]

In all honesty, I think I'd stick with the G240 that's already in it.

I'll verify it's a G240 this weekend and if that's the case I'll use it since it's 0.81 on 5th. I have all the shafts available anyway so it's np.

Edit: Gonna have change the ring and pinion on the LSD anyway, I found the tag in a bag with it's bolts and it says S3,91 ...so I'm gonna have to go lower.

[Wanganstyle]

In all honesty, I think I'd stick with the G240 that's already in it.

I'll verify it's a G240 this weekend and if that's the case I'll use it since it's 0.81 on 5th. I have all the shafts available anyway so it's np.

Edit: Gonna have change the ring and pinion on the LSD anyway, I found the tag in a bag with it's bolts and it says S3,91 ...so I'm gonna have to go lower.

If paired with a 2500cc engine natively the gearbox should be a Getrag g250- it's the most common 24v dohc gearbox for e36, e39, E46 chassis- all 2500cc had them.

The gearbox should have a vin sticker on its bellhouse you can reference.

G250 pairs well with anything between 2.93-3.46: I'm running a 3.46 with mine.

To tell the gear ratio pop the diff cover and look at the ring gear; it's stamped with a code; post it and I'll tell you what it is.

One can also count the ring gear teeth # and divide by pinion teeth #.



Sent from my SAMSUNG-SGH-I337 using Tapatalk

[N-Gen]

The M50 came with a g220, it wasn't the original engine since the VIN that was supplied on the ECU shows that it had an A/T.

The g240 is in my E30 as I believe it's the box that's standard in the 316i.

Keep in mind that this is all Euro spec.

[Wanganstyle]

The M50 came with a g220, it wasn't the original engine since the VIN that was supplied on the ECU shows that it had an A/T.

The g240 is in my E30 as I believe it's the box that's standard in the 316i.

Keep in mind that this is all Euro spec.

I ran a e46 euro spec 320d gearbox on my usa e30 m20 engine; not that much a stranger to euro gearboxes :)

Does the gearbox have a vin number sticker?

G220 is not unusual in usa; it's the gearbox used in our usa spec e36 318 with M44 engine.

Are you sure you want to use a 4 cylinder gearbox with a 2500cc 6 cylinder? It will work and the final drive will be same choice as a zf 5 speed.

Prop shaft I'm not sure you can use an off the shelf one - i don't think there was ever a g220+24v engine car by bmw in a e30 or e36 chassis. But it's always possible

G240 Is also in usa; it's the e30 m52 gearbox with 5th gear overdrive

G220 is a e36 era box with 5th gear 1:1


For e30 24v swaps the e36 gearbox and engine and driveshaft is used.

The 4 cylinder engines don't interchange mounting or prop shaft with the 6 cylinder units.

E36 euro 320i 2000cc is the smallest displacement 24v engine and came with getrag g250; same as our usa spec 2500cc 325i

E36 328 and above all had zf 5 speed gearboxes. This is what we run in our 24v e30; bolts right in.

24v engine (m50/52/54/s50/52/54)

+g250 and g250 driveshaft
Or
+zf320 and zf driveshaft

[N-Gen]

The g220 was paired to the M50B25 before sent to me, bought them as a package.

I can use the g240 (if indeed it is a g240) that's already in my 316i. I just need to figure out which would be the best to drop in so I can pick the LSD ratio.

Am I correct in saying I only need the ring and pinion swapped out of the LSD to change the ratio?

[Wanganstyle]

The g220 was paired to the M50B25 before sent to me, bought them as a package.

I can use the g240 (if indeed it is a g240) that's already in my 316i. I just need to figure out which would be the best to drop in so I can pick the LSD ratio.

Am I correct in saying I only need the ring and pinion swapped out of the LSD to change the ratio?

Ring and pinion would be what sets the ratio yes.

What ratio did you want? I've got a range on my shelf

Sent from my SAMSUNG-SGH-I337 using Tapatalk

[N-Gen]

I need to find what box I currently have in the eta and then decide between that and the g220.

I think it would be wise to choose a diff ratio after the box has been decided.

Sent from my LG-P880 using Tapatalk