One of BMW enthusiast’s favorite manual transmission is the ZF gearbox that came in multiple different generations of cars. As good and strong as this transmission is, there was a fault that BMW found, forcing them to issue a couple of service bulletins and offer a repair kit for the problem.
In the ZF 260Z/280Z/310Z and 320Z, the transmissions developed an issue with the detents which increased the force needed to disengage the gears and/or increased the force needed up to the gear escapement when engaging gears.
This is only an issue to be considered if it occurs with the transmission is at a normal operating temperature. The viscosity of the oil means that the incorrect diagnosis cannot be ruled out when the transmission is cold.
The cause of this issue, is the detent pin catches in the pilot hole (bushing).
Two BMW service bulletins were released.
What is a Technical Service Bulletin (TSB)
An automaker issues a technical service bulletin (TSB) when it becomes aware of common problems with a particular make and model, often from one or more model years. Those problems may have been reported by car owners, repair shops, or discovered by the automaker itself. When the automaker finds a solution to the problem, they can issue a TSB that advises its own service bays on how to fix it. These bulletins can cover issues such as faulty switches, sensor malfunctions, or unusual noises.
What Will You Experience In Your Transmission If You Have This Problem?
It is difficult to move the gear lever into and out of the 5th /reverse gear shift gate.
The gear lever does not automatically move from the 5th/reverse gear shift gate back to the center position (5th gear lean)
No shift gate guidance (sloppy shifter)
Affected Engines:
E46 M47 start of series production until August 2001
E46 M47 (318d) start of series production until March 2002
E46 M52TU B28, M54 B30 start of series production until March 2002
E39 M47 start of series production until March 2002
E39 M52TU B28, M54 B30, M62 B35 start of series production until March 2002 E39 M54 B25 (Touring) start of series production until March 2002
E53 M45 B30 start of series production unlit March 2002
E36/Z3/ M52TU B28, M54 B30 start of series production until March 2002
E36/Z3 S50/S52 start of series production until July 2000 E367/ S54 start of series production until March 2002
E38 M51, E38 M52TU B28, M45 B30, M62 B35 start of series production until end fo series production
Is it Hard to Fix?
The solution to fix this issue is not as hard as you think but it does take some mechanical experience, and a little confidence to work on a transmission. You will need to remove the transmission to resolve this issue. We have created an easy walk-through video (below) to show you what it takes to replace the detents and bushings.
We have also created an easy kit that includes all of the components you will need. To drive the bushings in, BMW recommends using their custom drift tools. These are no longer available from BMW, but we created exact replicas that you can purchase for an extra cost. These are recommended, but customers have been able to use a series of other tools (like sockets) to drive the bushings in. The advantage of using the official drift tools is, it drives the bushing in at the exact depth needed. This creates a foolproof method to prevent any mistakes.
Links to the BMW Service Bulletins:
Walk Through Video:
Links to Purchase Kit and Special Drift Tools: