JimTheBarber

Isn't this basically what A8'ers are complaining about?

1999 BMW 740IA Recall ID from NHTSA: 99V005000
Auto Recall Date: 19990104
Vehicle Component: POWER TRAIN:AUTOMATIC TRANSMISSION
Estimated Vehicles Affected: 249
1999 BMW 740IA Defect Summary:
VEHICLE DESCRIPTION: PASSENGER VEHICLES EQUIPPED WITH A 5HP24 AUTOMATIC TRANSMISSION. PREMATURE WEAR OF THE RING GEAR CAN OCCUR, LEADING TO THE LOSS OF 1ST, 2ND, 3RD, AND REVERSE GEARS.
Defect Consequence:
IF THIS PROBLEM OCCURS, THE CAR MAY NO LONGER OPERATE IN REVERSE, 1ST, 2ND, OR 3RD GEARS.
Remedy:
DEALERS WILL REPLACE THE AUTOMATIC TRANSMISSION.
Notes: BAYERISCHE MOTOREN WERKE,<ul><li><a href="http://www.automallusa.net/1999/bmw/7-series/recalls.html">1999 BMW 7-series recalls</a></li></ul>

tozoM8

That tranny looks a bit different from ours. I don't know what ring gear they refer to. That problem called a "hard part failure". Our tranny don't have hard part problems just seals and O-rings failure

dimitristx

Maybe we buy BMWs next time?

jazbo123

Although it's probably another piece of evidence of the general quality of the ZF5.

JimTheBarber

Based on what I have read, the "ring gear" is the large containing cylinder, that has toothed gear on the inside that contains the planetary gears.

The ring gear does not move, the other gears travel on it (that is, the ring gear is the outside tooth, the "sun" gear is the inside tooth, with the other gears riding in between sun and ring).

It is the red gear found here:
http://en.wikipedia.org/wiki/Epicyclic_gearing<ul><li><a href="http://en.wikipedia.org/wiki/Epicyclic_gearing">http://en.wikipedia.org/wiki/Epicyclic_gearing</a</li></ul>

tozoM8

in the 5HP24.