M/T - Decreasing Cold Shift Efforts
84BMW02Group 23 Transmission - Manual
Bulletin Number 23 03 84 (884) Page 1 of 2
Montvale, N.J. September, 1984 Technical Dept.
This bulletin supercedes SI 23 02 81 (521 and 23 03 83 (787) which should be removed from your SI binder and discarded.
SUBJECT: DECREASING SHIFT EFFORT OF 4- AND 5- SPEED MANUAL TRANSMISSIONS IN COLD CLIMATES.
MODEL: ALL MODELS
DECREASING COLD SHIFT EFFORTS (Transmissions with Synthetic Fluid)
Synthetic fluid is very viscous and shift effort may be excessive at cold temperatures. Therefore, depending upon when a vehicle is sold and the customer's expected mileage accumulation before the next service, it might be desireable to install another fluid in place of the synthetic fluid at the 1200 Mile Inspection to "climatize" the vehicle for winter as shown below:
DECREASING COLD SHIFT EFFORTS (Transmissions with SAE 80 Gear Oil)
BMW approved "straight weight" engine oils (preferably SAE 30) or automatic transmission fluids may be used in place of BMW approved manual tranmission gear lubricants during the winter months in areas subjected to low ambient temperatures on BMW 5-speed transmsissions as well as 4-speed transmissions to reduce shift effort. Best results in shift effort reduction are obtained by using ATF.
When using engine oil or ATF, the effort required to shift is only less at temperatures below 59 degrees F (15 degrees c).
To maximize the effect of the use of "straight weight" engine oil, the appropriate viscosity BMW approved engine oil is recommended for the ambient temperatures encountered as shown on this page. Multi-viscosity oils must not be used.
The use of engine oil or ATF will not affect the durability of the transmission; however, a critical customer might notice a slightly higher noise level due to the change in oil noise damping characteristics.
For summer operation, it is recommended, but not required, that ATF or engine oil be drained and replaced by the normal lubricant.
ENGINE OIL SPECIFICATIONS FOR USE IN BMW 4-AND 5-SPEED MANUAL TRANSMISSIONS
Only use brand-name HD "straight weight" oils for spark ignition engines, API class "SE".
Which SAE grade is used depends on the air ambient temperature range of the season.
The chart indicates the SAE grades to be used depending on the predominant air ambient temperature.
The temperature limits set by the SAE grades may be exceeded for a short period.