AU causes damage to the automatic transmission ?????

Hi V8tler

Is this possible with V8 ???????

AU examination can destroy automatic transmissions!
As the BMW Group already announced in May 1994, the main exhaust gas test can lead to transmission damage for BMW vehicles with automatic transmissions.

Situation: In the case of vehicles with automatic transmissions, it can be damaged or damaged during exhaust tests (AU). the failure of the lamella couplings, which the test steps take too long at higher speeds.

This applies primarily to the test of the "highest speed unloaded" for diesel engines, if it lasts longer than 1.2 seconds, as currently prescribed (as at May 1994), and for Otto vehicles with Lambda control ("G-Kat") the conditioning phase of 3 minutes at n=3,000 rpm.

This damage is caused by the high pressure in the hydraulic oil circuit at engine speeds above approx. 2,500 U/min., which via operating and/or wear-related coating points lead to a pressure attack of the clutch discs. Because of the "P" or "N" still standing drive shaft at selector lever position, increased wear on the linings of these couplings occurs.

In the case of the ZF automatic transmission of type 4HP22, the lamella package of "A" forward operation is no longer possible under the test conditions currently specified (status 5.1994).

All BMW vehicles with automatic transmission

In the case of a standing vehicle (selective lever in position "P"), the following operating points (speed/time) shall not be exceeded:

Engine speed = 2,500 rpm -> max. 15 minutes

Engine speed = 3,000 rpm -> max. 60 seconds

Engine speed = 5,000 rpm -> max. 1.2 seconds


is a question to the specs !!!!!!

Cu wolfgang :-)