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#1 Overdrive?
Posted: Tue Sep 13, 2016 1:40 pm
by Hugo
Is it possible to fit an overdrive box to a Series 2 Roadster? I would prefer that to a 5 speed, but if it won't fit.......
#2 Re: Overdrive?
Posted: Tue Sep 13, 2016 2:14 pm
by Heuer
No, it won't fit. You can use a Jaguar MOD (manual with overdrive) to replace the auto box on the 2+2 though.
#3 Re: Overdrive?
Posted: Tue Sep 13, 2016 3:36 pm
by iani
Jaguar MOD from S-type or XJ6 can replace any 2+2 'box, not the MOD from a MK2 though as the rear extension is too long.
Ian
#4 Re: Overdrive?
Posted: Wed Sep 14, 2016 8:02 am
by abowie
To decrease revs at motorway speed your options include:
1. Fit a new 5 speed box designed for the car. Best one is the JT5 from the US. There are other options too. Cost is big $$$$
2. Change your diff.
If you currently have a 3.54 diff, you will find a 3.07 a big improvement.
If you currently have a 3.07 you can go to a 2.88 from an XJS. This will make racing starts in first gear a little awkward but the 4.2 engine has bags of torque and will otherwise cope well. Cost is $$ in comparison to the 5 speed box but you will have to rejig your speedo and odometer.
I have a 3.8 with a 3.54 diff and a JT5 box. It's brilliant. Fast off the line and 2200 rpm at 70mph.
I also have a 4.2 with a standard 4 synchro box and a 3.07 diff. It's just as good but 2900 rpm at 70mph.
It all depends on how you drive your car. Me? I drive it on windy 50mph and 60mph roads through the hills, and not so much on the motorway.