Automatic gear selection on an early XJ6

Hi. I am operating a Mark 2 which has an early XJ6 3 speed auto. I am not aware of the exact model details of the trans. It works well and shifts through all gears. Kicks down etc. However I am not able to select and hold low. From stop I can select 2 and it will move off normally in low and then change to 2 which then holds until I change up to Drive. On the go I can manually shift from drive to 2 but not low. Starting in drive works as it should. Shifts from low to 2 to Drive. Can anyone tell me if this is normal? Thank you.

These are the instructions for the XJ6 with early Type 8 BW box

It could be a BW 35. Aluminium housing or cast iron? Shift cable, linkage or vacuum capsule?

I have a BW8. It comes with PRND2D1L and in D2 it will start in 2nd. D1 does all three gears.

If put into L it will go into 2nd and below ~20kph it will change down into low where it will stay.

The usual features of automatic gearboxes is to always move off in first gear, Tony - irrespective of gear selection; in ‘1’ the box will not upshift. In ‘2’ the gearbox will then upshift to second, but will not upshift further - but will downshift, depending on road speed and pedal position. In ‘D’ it will upshift through all gears according to designed shift speeds - and again downshift depending on road speed and pedal position.

Manual downshift, from ‘D’ or ‘2’ to ‘1’ is normally ‘prohibited’ by the box itself if road speed is ‘excessive’ - basically to avoid overreving the engine. The specifics may vary with box and engine configuration - it is preset in the valve body for the original combination of engine and gearbox…

To me, your box seems to behave as it should…:slight_smile:

xj6 85 Sov Europe (UK/NZ)

Thank you guys.

Frank the question is whether or not I should be able to select low. The transmission operates normally in all other respects. But I am not able to select low.

Regards, Tony.

BW8 in L always goes to 2nd (not sure about high speed…) and at ~20 kph it goes hard into 1st.
The BW66 (quite similar to the 35, 65) went into 2/1 if selected. You should be able to select low.

We then need to know which box is fitted, Tony…

When a ‘low’ position is shown on the shift quadrant it should certainly be selectable - as David also says. The problem may just be gear selector adjustment - which differ somewhat with type…

xj6 85 Sov Europe (UK/NZ)

xj6 85 Sov Europe (UK/NZ)

That sounds odd, David, and counterintuitive - source…?

xj6 85 Sov Europe (UK/NZ)

I believe David has misspoken,

The BW8 will start in 2nd if “D” is selected, but will indeed start in 1st if “L” is selected
(at least on my car)

The OP can confirm what sort of gearbox he has by checking if it has an iron or Al case

he may also have a BW12

The BW8 has a big “8” on the case

I haven’t misspoken but I wasn’t clear at all…

I meant to say that when in 3rd gear the BW8 will go to 2/1 (at appropriate speeds) when L is selected

When starting in L it will stay in 1st.

In D2 it will becomes a two speed transmission, 2 & 3 only.
In D1 it has all three gears and works as one would expect.

Up to Tony now, he‘ll be able to see what he has by crawling under and taking a few pictures.

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The DG box will shift into low at any speed, or the one in my Mk 1 did, at least. I was driving along at 70 mph when a milk tanker pulled out in front of me, brakes failed, blown wheel cylinder, so selected low. Rev counter hit the peg, but no damage ensued.

That sounds more like it, David…:slight_smile:

Which means that the appropriate quadrant would (confusingly?) be marked ‘L’, D2 and D1. Thought Tony should still be able to select low gear…?

xj6 85 Sov Europe (UK/NZ)

Admittedly, the BW 8, being rock solid, was meant for the US market with powerful V8s or more - and lots of drivers with manual gearing preferred to drive off in second gear, or higher to avoid shifting with possibly non-synchro boxes…:slight_smile:

xj6 85 Sov Europe (UK/NZ)

I find D2 useful. It’s LD1D2.

I use D2 almost all the time (BW8)

But your ‘L’, when selected, does work, Tony…?

xj6 85 Sov Europe (UK/NZ)

Thanks everyone. Very helpful

Hi Frank.

No, I cannot select L. It appears on the selection graphic D,2,L

However I can only select D which gives me all three gears or 2 which gives me low and 2. As this is a Mk2 with an XJ6 transmission I am unsure if the graphic, which I think has been altered, is at odds with the reality of an XJ6 transmission?


if L is selected in any gear, the box will change down 1 gear

If started in L, I think it will stay locked in 1st gear, (but maybe it will switch up to 2nd,
cant remember for sure)

Its possible the selector gate does not match the transmissions selector cable/gears, which can cause issues

You need to positively identify what trans you have by getting under and taking photos and posting them here, as people will be able to tell which type it is, and what the matching selector position should be

My Daimler V8-250 has a BW35 and will start in first gear if I select D1, otherwise it starts in second gear. I have read that starting in second gear involves more torque than is good for the box but I don’t know if this is true.

When I first had the car the L position wouldn’t select, so the box was working exactly as Tony’s does. Under the dash to the left of the steering column (right hand drive car), where the shift cable ends is an adjustment. ‘Tightening’ the cable 2 turns of the nut fixed it.