540i Transmission Fluid Change?

[mattronic 1]

Specific temp is between 30-35 degrees celsius to start the checking process, 40 degrees to check the level, but allows up to 50 degrees before the expansion will affect the levels and the results will be too low.

The overflowing I had at the beginning would be explained by the higher temperature when I started.

I had noted the temperatures while doing my research, but the guides I was following weren't so specific, so here is the specific guide for ZF 5HP24 transmission:

http://www.thectsc.com/5hp24-transmission-fluid-level-procedures

A. Transmissions fluid level checking.

1) The transmission fluid temperature must be between 30°C and 35°C before checking can begin. Use test equipment to determine the trans temperature.

2) The vehicle must be level with engine running at idle speed and air conditioning turned on.

3) Step on the brakes firmly, apply parking brake fully and shift to D and R, briefly pausing in each position before shifting back to the Park position.

4) With the engine running at idle speed and the selector in Park position, remove the filler plug. Monitor the transmission temperature, if a small stream of oil runs out at 40°C, the fluid level is correct.

5) If no oil runs out when the filler plug is removed, the fluid level is too low and oil needs to be added until it overflows.

6) With engine running, install the oil filler plug and tighten to proper torque.

 

B. Adding fluid after repairs.

1) With the engine stopped and the transmission in Park position, remove the oil filler plug. Add transmission fluid until a small stream of oil runs out.

2) Insert the filler plug and tighten by hand. Start the engine.

3) With the engine running, remove the oil filler plug and add transmission fluid until a small stream of oil runs out. Insert the filler plug and tighten by hand.

4) Follow the “Transmission fluid level checking” procedure described in section A. above.

 

C. Notes on fluid level and adding procedure.

1) Use only ZF-LifeguardFluid5 or OEM approved transmission fluid.

2) If the transmission temperature rises above 50°C during the fluid level checking procedure the resulting oil level will be to low. Let the transmission cool down and repeat the fluid level procedure.

3) Have transmission fluid and a suitable oil pump available before starting the fluid level procedure. The transmission fluid temperature will rise quickly during the checking procedure.

Edited December 13, 2016 by mattronic

[zero 1162]

Great post.

Thanks for the detailed info.

[*Glenn* 854]

We do our transmission oil level checks at 45c using live data, not an external temp sensor source

[mattronic 1]

All topped off this morning following the above procedure.  A good check is that the same quantity of fluid drained out should go back in, and that has been the case (more or less).  Reverse is now engaging smoothly, but still slips.  Thanks everyone for your help and input.  I'll be saving up to pass this on to the experts, a manual conversion appeals, but seems like too much of a job for me to get into...