Hi

My preHE 1977 had the driveline from a 1989 XJ12 mounted in 1996.

As I understand it, the GM400 gearbox (which I now have) has a sports mode, while my original BW12 did not have that option.
As I still have original interior there is no buttons available for the sport mode selector.
I have found a small switch placed between drivers seat and transmission tunnel. I have never tried to switch it, but now it just came to me, that it could be the sports switch. The owner at the time of mounting the engine owned the car until his death, so there is no information available from previous owner...

What difference does the sports mode do ? It would be nice to know in advance before testing the switch,,,

 

Hi Leo,

I wasn't aware that sport mode was available on earlier 3 speed auto transmission.

On post 1993 V12 6.0 they had 4 speed auto transmission 4L80E , the sport mode enabled first gear for take off and held lower gears for higher revs. While normal mode would start in second gear and change up sooner.

 

Paul is correct, no sport mode on the TH400.

 

Thanks, then I don't have to think more about how to make it work

I will still have to test the switch though...