transmission service One litre deficient

[SkiJunkie]

Serviced the gearbox on the 420 SEC; the handbook specifies adding 7.7 litres.
I added 4 litres with the engine off, started the engine, and attempted to add the remaining 3.7 litres, but I could only add an additional 2.7 litres before realising I need another litre of oil.

The instructions instructs to operate the vehicle through its gears after adding the whole volume of 7.7 litres.
Having put just 6.7 litres, which is 1 litre short, I opted not to engage the car's gears and turned it off until I filled it to the full 7.7 litres.

Is there an issue with not having engaged the gears? I am concerned about the gearbox sump overfilling and maybe leaking overnight.

[GamingLegend]

The amount specified in the handbook is inconsequential, since, unlike engine oil, not all fluid is extracted during a gearbox repair. Utilise the fill markings on the dipstick to replenish to the appropriate level. Another method to ascertain this is to measure the fluid you extracted, assuming it is still available, and replenish the same volume. I bet you did not eliminate 7.7 litres.

[MotoEnthusiast]

Have you evacuated the torque converter?

[SkiJunkie]

indeed, I am uncertain if I should engage the gears with 6.7 litres of gearbox fluid to circulate the oil into the torque converter or whether the torque converter has already been filled throughout the process of filling and idling the engine in Park.

[AstronomyFan]

My 420 SEL required around 7.75 to 8 quarts of gearbox fluid.
The instructions instructs to first pour 4 litres to start the vehicle, then gradually add the remainder while changing gears.
I would refrain from adding the remainder, since it may lead to overfilling.
To do the final adjustments, operate the gearbox at full temperature and drive the vehicle for 20 minutes. The adjustment range should be around 200 mL between the minimum and maximum levels. It is advisable to begin with a quantity slightly below the minimum level.

It is simpler to add than to delete.

[AstronomyFan]

[TravelBlogger]

At least one litre of old fluid remains in the transmission cooler and pipes. Do not rely on the instructions; instead, using the dipstick fill markings.

[SkiJunkie]

Thank you. I have the instructions from the manual. Currently, there are 6.7 litres in the gearbox. Should I shift through the gears or wait till I can add an additional 200 millilitres?

[AstronomyFan]

If the dipstick reads slightly below the minimum threshold at working temperature, I would proceed without concerns.

200 mL between the minimum and maximum markings.

Maintain a minimum speed until you have driven the vehicle for 20 minutes on the highway.

[SkiJunkie]

I am presently 1000ml short; are you suggesting it is still OK to shift through the gears?

[AstronomyFan]

If the level is just below the minimum point on the dipstick while the vehicle is idling, it is OK.

[SkiJunkie]

I have purchased more oil, which I will use to fill the engine before testing it through the gears.

[WebWizard]

What is the reason for delay?

Cycle through the gears before to adding any more fluid. The purpose of passing through the gears is to get an exact measurement of the level. It is simpler to augment than to eliminate if one exceeds the limit.

[SurfingPro]

Despite all this discussion, you have yet to disclose the level shown on your dipstick.