ZF4HP22 - Das Pinzgauerforum (2024)

4HP22 failures
The 4HP22 transmission can be rendered undriveable when held on P or N setting and too high engine rotation speed is applied for too long, for instance during emissions testing. Examples of situations that could lead to transmission failure include warming up the catalytic converter on petrol engine-powered vehicle with too high RPM, or while measuring amount of smoke on diesel engine-powered vehicle and keeping the throttle full for too long time.[17] The correct procedure would be to stop the engine for at least 90 seconds, do the test (without selecting again D or R, this means without re-pressurizing the gearbox) for no longer than a minute, and if the procedure must be repeated, stop again for at least 90 seconds and repeat. Another issue is the governor valve sticking, which can be caused by contamination. i.e. clutch plates or other parts disintegrating. The fine debris finds its way past the filter and tends to accumulate in the governor, causing it to stick. A temporary solution is to remove and clean the governor. The problem will often recur as debris from damaged parts continues to build up in the governor. If the problem continues after cleaning the governor then it may be necessary to replace the autobox if it cannot be fully reconditioned. Usual symptoms are failing to shift after 1st gear while the gearbox is still cold, and then failing to kickdown to 1st while at a stop. The governor is located at the end of the gearbox and usually it starts to work again after a cleanup.
Quelle: engliches Wikipedia ZF4HP22

Was ist bitte hiervon zu halten?

Yes this was a common problem with Volvo 740/ 940 cars equiped with the ZF4HP22 automatic....they even had a special exception at the emmision testing facilety ( vehicle inspection center) and where left out for these tests becouse the automatic gearbox could self destruct under high revs while being in left in park....

Same problem with the Land rover p38

The common fault which often destroyed 4hp22 clutch packs if revved in neutral or park after the transmissions had been in gear was fixed by the time the P38 came along. The front clutch pack's pressure failed to bleed down and would be torn to shreds by revving in park or neutral. To be safe with automatic transmissions, the engine should always be switched off for 30 seconds to allow the fluid pressure to dissipate completely, then restarted and left in park.

Das Problem ist bei dem Getriebe schon lange bekannt. Da gibt es auch genaue AU-Anweisungen dazu.

Gruß Udo

Rhönpinz hat geschrieben: ↑7. Nov 2019, 19:00...also wenn ich mit dem Pinz zur AU muss, brauche ich mir keine Sorgen zu machen weil die Werkstatt Bescheid weiss?

Darauf würde ich nicht vertrauen.

Udo hat geschrieben: ↑8. Nov 2019, 07:10

Rhönpinz hat geschrieben: ↑7. Nov 2019, 19:00...also wenn ich mit dem Pinz zur AU muss, brauche ich mir keine Sorgen zu machen weil die Werkstatt Bescheid weiss?

Darauf würde ich nicht vertrauen.

Ich auch nicht...

Schick mir beime Mailadresse per PN.
Ich sende sie dir gerne zu.

Gruß Udo