Anyone replaced a Boxster reverse light switch?

[BartyB]

I've finally got around to replacing the reverse light switch on our 3.2 S / 986 (six speed transmission) which failed a few weeks back. It looks straightforward enough to replace but cannot find any reference to tightening torque or whether any sealing or locking compound should be applied to the thread on the switch.

From what I can determine, there is no washer, seal or O-ring between the mating faces (of the switch and gearbox casing). My inclination is to put a smear of locking compound around the thread, tighten finger tight and then turn 1/4 turn with a socket.

Before I go ahead though, I wondered if anyone on the forum has replaced a reverse light switch and would care to share their experience on undertaking the job? Thanks.

Alan.

 

[BartyB]

Guess that's a no then...

 

[Motorhead]

Alan,

Sorry, can't speak from experience but I would think there would be evidence of locking compound - if used - when you remove the old switch. Removal will also give you some idea how tight the new item needs to be. "Nipped up" would be my guess - your quarter turn sounds about right.

Jeff

 

[BartyB]

Cheers Jeff. Thanks for the helpful input.

I've set aside some time this weekend so will find out if there's anything on the threads then.

Alan.

 

[BartyB]

Just in case anyone else needs to do this job, after a bit of searching through Torrent sites I eventually found a reference to tightening torques for the G86/20 transmission (6-speed) in the Boxster Workshop Manual (Group 3 / Page 3-107) which states that the "Reversing light switch on transmission" with M12 thread should be tightened to "15.0 Nm (11.0 ftlb)".

Alan

 

[BartyB]

Having completed the job at the weekend, in practice it's very straight forward and can be done in less than an hour. However, before replacing the switch (part number 996.606.133.00 - £30.50 from Porsche Centres) I first tested it (by removing the connector and connecting a digital multimeter to the two pins in the switch) and established that it was permanently closed irrespective of whether it was in reverse or not. The most difficult thing is raising the car up sufficiently to give yourself some room to work underneath at the rear. I used the following tools to do the job: • A low trolley jack, wheel chocks, ramps and axle stands • A slotted screwdriver • Solvent (e.g. brake cleaner, white spirit, petrol, etc.) • Old toothbrush • A short 19 mm ring spanner • Threadlock (eg Loctite 270) • A 19mm deep socket • A torque wrench The process: 1. Raise car using suitable lift or jack 2. Support the car with stands under the jacking points and/or place appropriate ramps under the rear wheels 3. Remove the connecting plug (use the slotted screwdriver to depress the metal clip whilst pulling the plug upwards from the switch body) 4. Clean around the switch with the toothbrush before removing it to avoid debris dropping into the gearbox 5. Unscrew the old switch with the 19mm ring spanner 6. Put a ring of threadlock around the thread of the new switch about mid way 7. Place new switch in gearbox casing 8. Screw the switch in with fingers until it cannot be screwed in any further making sure the thread is not crossed 9. Tighten the switch to the specified tightness using the 19mm deep socket and torque wrench 10. Replace connecting plug making sure it is located and fully seated on the switch 11. Test for correct operation 12. Lower the car 13. Feel happy you’ve just saved yourself around £120

Pic 1. New switch (part number 996.606.133.00)

Pic 2. New switch installed in car

Notes: When I removed the switch it was accompanied by the sound of a slight escape of air from the gearbox. There was no washer or O ring around the old switch and no oil came out of the gearbox when the switch was removed.

Have fun. Alan

 

[BartyB]

As a post script to the problem of a series of failed reverse light switches (it has happened to me three times since 2007) I cut open the failed switch and examined its internals. I concluded that the switch return spring is weakened by being compressed for long periods of time and that leaving the car parked in reverse gear every night may have caused this. I'm happy to say that ever since replacing the switch, the car has been parked in 1st gear and that no further problems have been experienced.