Transmission

[JCL]

Originally Posted by Mikedd

I have put on a fair number of miles since I did that very un scientific poll and I am still good transmission wise as well. I think we should resurrect the poll to get even more data to perhaps dispel the "the urban legend" of transmission fluids. Ha

Save the effort on the poll, it is impossible to get real data. I figure I have stirred the pot enough here today, now you come along to do the same thing...

[X5Sport]

This may, or may not, add to the debate but I have just had my transmission rebuilt after the torque converter failed (lock up sprag clutch sheared) and caused catastophic damage due to debris in the oil damaging various clutches downstream and ruining the oil pump to the extent that metal shavings from the pump wrecked the gearset for 1st to 3rd too. The rebuild shop is a ZF specialist and they want the car back after 6months/6,000 miles to do a complete fluid and filter change. The original failure occurred at 42k miles.

More worryingly - and I pass on on for that reason - was his comment that they are now seeing so may of the 6-speed auto failures (not just in BMWs) they now keep the spares on site whereas they used to special order them. Most of the failures are actually being caused by electronics or electrically controlled hydraulic devices breaking rersulting in downstream failures when vavles operate incorrectly or fail to operate at all - and not fluid related.

[JCL]

Originally Posted by X5Sport

This may, or may not, add to the debate but I have just had my transmission rebuilt after the torque converter failed (lock up sprag clutch sheared) and caused catastophic damage due to debris in the oil damaging various clutches downstream and ruining the oil pump to the extent that metal shavings from the pump wrecked the gearset for 1st to 3rd too. The rebuild shop is a ZF specialist and they want the car back after 6months/6,000 miles to do a complete fluid and filter change. The original failure occurred at 42k miles.

More worryingly - and I pass on on for that reason - was his comment that they are now seeing so may of the 6-speed auto failures (not just in BMWs) they now keep the spares on site whereas they used to special order them. Most of the failures are actually being caused by electronics or electrically controlled hydraulic devices breaking rersulting in downstream failures when vales operate incorrectly or fail to operate at all - and not fluid related.

Thanks for posting. It is entirely anecdotal, but it is also consistent with the types of failures that have been reported on this site over the past four years or so.