Shift from 1 to 2, function - GF27.60-P-4013G

TRANSMISSION 722.6

1st gear engaged

Fig 1: Identifying Shift From 1 To 2 Function - 1st Gear Engaged

Shift phase

Fig 2: Identifying Shift From 1 To 2 Function - Shift Phase

2nd gear engaged

Fig 3: Identifying Shift From 1 To 2 Function - 2nd Gear Engaged

Aim

Engage front multiple-disc clutch (K1), disengage front multiple-disc brake (B1).

Operation

1st gear engaged

The end face of the 1-2/4-5 command valve (31a) is kept depressurized via the 1-2 and 4-5 shift solenoid valve (Y3/6y3). Via the 1-2/4-5 holding pressure shift valve (28a), working pressure (p-A) is applied to the front multiple-disc brake (B1). The front multiple-disc clutch (K1) is depressurized.

Shift phase

Via the 1-2 and 4-5 shift solenoid valve (Y3/6y3), the shift valve pressure (p-SV) is directed onto the end face of the command valve 1-24-5 (31a). The 1-2/4-5 command valve (31a) is displaced and the shift pressure (p-S) coming from the 1 -2/4-5 shift pressure shift valve (29a) via the 1-2/4-5 command valve (31a) is directed to the front multiple-disc clutch (K1). At the same time the front multiple-disc brake (B1) is subjected to overlap pressure from the 1 -2/4-5 overlap regulating valve (30a).

The B1 pressure acting on the end face of the 1-2/4-5 shift pressure shift valve (29a) is superseded by the working pressure (p-A). The increasing shift pressure (p-S) at the front multiple-disc clutch (K1) acts on the annular area of the 1-2/4-5 overlap regulating valve (30a) and reduces the overlap pressure regulated by the 1-2/4-5 overlap regulating valve (30a). With an appropriate pressure level at the 1-2/4-5 holding pressure shift valve (28a) this valve switches over.

2nd gear engaged

After the gear change is complete, the pressure on the end face of the 1-2/4-5 command valve (31a) is reduced via the 1-2 and 4-5 shift solenoid valve (Y3/6y3) and the command valve is pushed back into its original position. Via the 1 -2/4-5 holding pressure shift valve (28a) working pressure (p-A) now reaches the front multiple-disc clutch K1) via the 1-2/4-5 command valve (31a).

The front multiple-disc brake (B1) is disengaged (depressurized). The spring in the 1-2/4-5 shift pressure shift valve (29a) pushes this into its original position.

	Operating pressure, function		GF27.60-P-3013G
	Shift pressure, function		GF27.60-P-3015G
	Modulating pressure, function		GF27.60-P-3016G
	Shift valve pressure, function		GF27.60-P-3018G
	Lubricating pressure, function		GF27.60-P-3014G
	Regulating valve pressure, function		GF27.60-P-3017G