Hi Guys,
I’ve just purchased a 1991 Daimler Double Six and the speedo wires are hanging from the back of the Diff. Does the other end plug into a speed transducer (Lucas part DAC7474) and if so, could someone tell me its location, as I can’t see a connection point in the boot or around the gearbox?
Thanks Jeff
Welcome, Jeff…
Initially, the speedo pick-up was at the diff - connected to the speedo. But in the later versions; the speed transducer is(!) the feed to the speedo - a mix of the two set-ups is not on.
Are you sure the electric wires hanging from the diff is for the speedo? The speed transducer on the GM 400 is at the front of the extension housing, left side…
Just for the record - do you have speedo reading - and a functioning driving computer…?
Frank
xj6 85 Sov Europe (UK/NZ)
**
Jeff,
We own a 1990 V12 Vanden Plas, essentially a Daimler Double Six badged for the North American market. It has the speedometer transducer mounted on the GM400 transmission and not the differential as in our 1990 XJ-S convertible.
Check your transmission for the speedometer transducer and wiring. I find it difficult to believe that Jaguar changed the Series III saloon speedometer design for the 1991 models approaching at the end of Series III production. Perhaps the original differential in your car was removed and it was replaced with one from an XJ-S and the wires were left hanging because they weren’t needed?
Paul
Thanks very much to you Frank and Paul. Followed your advice and the Speedo and trip computer were working fine. So as you suggest it must be a replacement diff from an XJS. Thanks so much for your help guys. Much appreciated. Jeff
Jeff,
I am glad that it was that easy. 
Most members on this list own XJ6s, but there are a few of us that own Daimler Double Six/V12 Vanden Plas/XJ12 cars. Please let us know if you have any other questions or issues with your car.
I have owned my V12 Vanden Plas for almost 9 years and I have done a lot of the work on it myself. I also owned XJ6s for 20 years but recently sold them, so I am conversant in XJ6, XJ12, Daimler Double Six, and V12 Vanden Plas as well a other models.
Paul
“conversant” … now that’s funny;-) Paul is playing the ball under the lawn! Ask him anything about 12 cylinder Jags and you’ll get perfectly documented info plus incredible pics …
No kidding, just kudos!
Best
Jochen
75 XJ6L 4.2 auto (UK spec)
Cheers Paul,
I’ve had an XJ6 before, but this is my first DD6 and being 1991, its difficult to be sure of what applies to my car vs the last of the XJ12’s. Everything now works on it after fixing the Sunroof, elec cooling fan relay wiring, tank sender and headlamp wiper arms, but it’s got some serious rust in the front chassis rails and I’ll need to take the engine/gearbox out to make it easier (and cheaper) to have fixed. Any advice you have thats out of the ordinary and unique to the DD6 engine/gearbox removal would be most welcome.
Cheers - Jeff
Where are you located, Jeff? And who told you about the rust in the “front chassis rails”? I’m just asking because, though there are many typical parts of the series XJ Jaguar bodies prone to rusting I hardly heard anyone complaining about the chassis rails.
While there are chassis like extensions of the monocoque body structure, they don’t seem to rust very often, maybe because they benefit from the oil losses of the engine;-)
The things that typically rust though, are the front lower cross members below and on top of the radiator and the supporting part holding the engine and the front suspension. You can see the first two in the pic above. They are DIY jobs. The last one is more serious, but still doable. You can suspend the engine and basically swap the suspension beam underneath.
If, in fact, you do have serious rust along the chassis extensions you might wish to check other critical parts, most notably sills and floor pan where the rear radius arms attach. If you find more rust there, you might well think about another car:(
Good luck
Jochen
75 XJ6L 4.2 auto (UK spec)
Jeff,
I have never removed and replaced the V12 engines in either our 1990 XJ-S Convertible or 1990 V12 Vanden Plas, but I have removed and replaced more than a few engines from our XJ6s and XJ6 parts cars that I purchased. In December 2018 I started a thread on this list titled “Engine transplant 1984 XJ6 Vanden Plas” that detailed the major steps, along with pictures, as I removed the failing engine in my 1984 XJ6 VdP and replaced it with a nicely running engine from a crash damaged 1987 XJ6 parts car. I recommend that you search the archives for that string as it will likely be very helpful to you as you tackle this project.
I live in southern California and rarely see any serious rust on our Jaguars. I did some rust removal and repainting in the engine bays of my two XJ6s, but nothing like what it sounds like you are tackling. Good luck.
Paul
Hi Guys,
I’m located in the UK and wanted a UK delivered car, so I was expecting rust. I was specifically looking for Westminster Blue over Magnolia and sunroof, so quite specific. It needs sills, radius arms points and rear seat belt anchor points, plus the lower supporting area holding the engine as you reference it Jochen and visible in the pic.
Everything works on the car (bar the A/C) and the interior is very good, so its really all about the rust. Financially, it won’t pay for itself, but I want to see it back to its former glory.
Jeff
Great quality pics in your engine transplant thread…already given me some ideas for my own job.
Cheers - Jeff
Jeff,
Thanks. This was the second engine transplant that I did on my Series III XJ6s. The first was when I successfully replaced the failed engine (#6 piston rings) in my 1987 XJ6 Vanden Plas with one from a nicely running 1986 XJ6 parts car. I posted a few times about that project along the way. When I needed to replace the failing (very low oil pressure and second blown head gasket) in my 1984 XJ6 Vanden I decided to post regularly about it and provide lots of pictures as a path for others to follow should they need to remove and replace the 4.2L XK engine in their Series III XJ6.
I took many hundreds of pictures during that work but only included a small number of them in my posts. I find that documenting each step with a notebook and pictures helps with reassembly. I also label the removed parts in plastic organizer boxes to help keep track of the parts that I remove and their order of removal. I have a policy that if I take something apart and end up with extra parts when I put it back together, that I have to eat those parts. 
Paul
Jeff,
your description sounds - and your pic looks - like you’ve got a wonderful donor car for a tired, but by-and-large rust free sand belt XJ hull. Even if you pay 2k for the car and 1k for the shipping it’ll still be cheaper, better and easier to work on than to restore the original. It is not a 1936 Lagonda, after all. Just my tuppence …
Good luck, whichever way you go … a German proverb goes like “many enemies lead to much honor”
Jochen
75 XJ6L 4.2 auto (UK spec)
Haha…thanks Paul, the thought of eating the extra parts will help me focus on proper labelling and photos if I do end up pulling the engine out. Jochen, your probably right with your comments and I’m definitely weighing up cost/time of holding onto originality vs selling/scrapping. The unemotional side would do the latter, but I’m a bit a bit sentimental and like a matching numbers car.
Not the first to be in this position and I’ll let you know the final call after I’ve shown it to the guy who’s done metalwork on other cars for me in the past.
Cheers - Jeff
Very handy to have a knowledgeable Daimler S2 VDP D6 to chat to …it’s a long life owning cars that most folks only recognise the name as I’ve found out with mine everybodies dad had one but they don’t know anything about them other than they were cheap to buy says it all. .
