Transmissions                                                                                                                               An appropriate transmission for the 335i can be found in many different models and series.  The 5-, 6- and 7-Series all had a transmission that will fit the bill.  Several models within each series will be possible sources.  For example:

e28: 525i 528i 535i M535i 
e23: 728i 728 733i 
e24: 628 630 628CSi 635CSi

The newer versions of the M30 also have appropriate transmissions.  If an older engine is to be used the transmission from a newer car can not be used.  The newer engines will, however accept the older transmissions.  Any of the following cars will be suitable donors for the transmission (to be mounted to a newer engine):

e34: 530i 535i 
e32: 730i 735i 

The sport transmissions from the following cars are also acceptable substitutes for the standard manuals listed above:

e28: M5
e24: M635CSi
e34: M5 3.6 M5 3.8
e30: M3
Alpina: B6 2.8 B6 3.5

The sport transmissions, listed directly above, all have close ratio gearing.  It should also be noted that the fifth gear in each of these gearboxes has a ratio of 1:1.   As a result a numerically lower differential is needed to provide a reasonable top speed. Those from the ETA cars are suitable; either the 2.93:1 or the 2.73:1 would serve this purpose well.

Transmission Cross Member
A custom transmission cross member can be manufactured to hold the transmission. The factory transmission cross member can also be reused.  An Alpina cross member can also be substituted for either of these two.

e34 transmission with the original transmission mounts from the e30
 

Alpina Cross Member (until 9/87): Alpina Part Number : 23 10 110

Transmission Cross Member for the Sport Transmissions
The transmission cross member of the e30 M3 fits perfectly with the sport transmission.  As a result the manufacturing of a custom cross member is not recommended.  It will be cheaper to buy an e30 M3 cross member.  
 

Transmission cross member from the e30 M3

M3 Transmission Cross Member: BMW Part Number:  23 71 2 225 261   2x Rubber Mount: BMW Part Number:  23 71 2 225 624 4x Square Head Bolt : BMW Part Number:  23 71 1 130 250

Note: Some of the older transmissions also have the same mounting points as the sports transmissions.  Here the e30 M3 cross member is also useable.
 

Alpina Started Using the M3 Cross Member in 9/87:  BMW Part Number: 23 71 2 225 261

Shift Linkage in Engine Position I
Alpina used the following parts for the sport transmission until 3/86: 
 

Heat Shield for Shift Linkage (Sheet Metal) BMW Part Number: 25 11 1 209 804 Shifter Rod: BMW Part Number: 25 11 1 220 541

They then switched and used the following from 3/86 until 9/87:
 

Heat Shield for Shift Linkage: BMW Part Number: 25 10 1 220 571 Shifter Rod: BMW Part Number: 25 11 1 220 541

Shift Linkage in Engine Position II  
Unlike in Engine Position I the heat shield for the shift linkage and the shift linkage itself must both be shortened in this position. 

Alpina used the following parts beginning 9/87:
 

Heat Shield for Shift Linkage: Alpina Part Number: 23 10 118 Shifter Linkage:  Alpina Part Number: 23 10 120

Shortening the Shift Linkage
 

	In this example a shortened version of the heat shield for shift linkage of the e23 735i is shown.  In this case the parts were bolted back together, making the shorter version.  The parts can be welded, for a more solid finished product.
	The shortened shift linkage is shown here.  Here it is provisionally held together with screws.  The completed version will be welded.   The shift linkage heat shield can also be seen here.  It is held to the body at the usual rubber mounting points.

Clutch
The original clutch: MF240/K (brown) can be used without any problems.  Under more extreme driving conditions a performance clutch may be needed.  Performance clutch kits can be had from a variety of suppliers.
 

Pressure Plate: BMW Part Number: 21 21 1 225 576 Clutch Disk: BMW Part Number: 21 21 1 223 120 Throw-out Bearing Release Arm: BMW Part Number: 21 51 2 226 729 Release Arm Pivot Pin: BMW Part Number: 21 51 1 204 229

 

Questions, Comments?