M42club.com - Home of the BMW E30/E36 318i/iS

DISCUSSION => Engine + Driveline => Topic started by: roadrunner75 on March 28, 2007, 05:37:12 AM

Title: Gearboxes differences on M42
Post by: roadrunner75 on March 28, 2007, 05:37:12 AM

Hallo

I have an E36 Coupè powered with M42; this is a 1992 318is.
The engine is identical as the E30 m42; it has 3 drive belts and the alluminium top of the oil canister.
I don't know exactly if my 5-speed gearbox is a getrag S5D 200G  or an S5D 250G.
I have some questions about it:

Where I can fin the identification number on the gearbox?

The two types are intercangeable or not?

If I need to buy an other one as a spare, I must put the same Type or I can take one from an other car( ex. a 318is E30, a 320i E36 or a 318i E36)??

I have replaced the ATF oil in it , but my second gear after 100 000 miles doesn't  engage very strong, because a principle of syncro wear...

Thanks for your attention,

1992 318is

Title: Gearboxes differences on M42
Post by: bar73k on March 28, 2007, 05:49:32 AM

any gearbox fitted to an m42 can be interchanged to another m42 motor

if you get a gearbox from a e30 m42 and put it into a e36 you will need to change
the clutch slave cylinder and the spigot bearing (the bearing in the crankshaft)
other than that everything else should be fine

gearboxes from m40's also fit with out any major mods

gearboxes from the m50, m52, s5x families also mount up to m42s but more than likely will need a modified (shortened) tailshaft

m20 gearboxes also mount up (only four main bolts hold the gearbox the the motor) but require a modified gearbox mount, modified gear selector and a shortened tailshaft. (the gearbox is twisted 15 degrees compared to the standard box)

Title: Gearboxes differences on M42
Post by: fabe on March 30, 2007, 05:49:37 AM

Quote from: bar73k;22348

any gearbox fitted to an m42 can be interchanged to another m42 motor

if you get a gearbox from a e30 m42 and put it into a e36 you will need to change
the clutch slave cylinder and the spigot bearing (the bearing in the crankshaft)
other than that everything else should be fine

gearboxes from m40's also fit with out any major mods

The gear ratios are different... E36 gearbox has a 5th gear ratio of 1:1 instead of 1:0.8 for the E30 gearbox.

Title: Gearboxes differences on M42
Post by: bar73k on April 01, 2007, 06:59:58 AM

Quote from: fabe;22511

The gear ratios are different... E36 gearbox has a 5th gear ratio of 1:1 instead of 1:0.8 for the E30 gearbox.

Oh yeh, forgot to mention that, you would need to change differential ratios to compensate for the difference.