So I bought a red 1975 Xj6 3.4L. Manual gearbox with O.D

So I found a car with extensive rust repairs, rear and front end from a xj12 S2. I think this is the oldest car I have driven so far… my mothers old SAAB being a -77.

The paint isn’t the absolute best, the red paint is the 3rd layer, second layer is military olive green, original color was some kind of darker blue. I love it being red though.

The leather upholstery is in good albeit dry condition. The seats are very comfortable. I have liquid leather for cleaning and conditioning.

Will fit another steering wheel, the one currently in it doesn’t look nice and has a plastic feel.
It corners very nicely and has a surprisingly small turning radius. It does wander a bit sideways when driving on country road. Will do wheel alignment.

Manual gearbox… This is what I want and prefer, but I do see why people preferred the auto box. It is a bit like driving old farming equipment. The pedals are heavy compared to modern cars, even the accelerator. I like it :slight_smile:
The overdrive works like a charm.

Does anyone know the make of the gearbox? I have read it is a Getrag, other info suggests it is jaguars very own. Does it have a part number? 4 gears plus the overdrive.

No radio.
Seller claims it didn’t come with AC, if it did, everything AC related is missing, as far as I can see. Retrofit?

Drinks oil, a lot of it, which is of course something I realized once the car was bought and paid for. No smoke on start up, but on acceleration. Will do compression test come weekend. I guess it has been run on modern non leded fuel with the led replacement additive. On the other hand, it hasn’t been in traffic for many years.

The electricals… well… I’ll get myself a wiring diagram and work it out.

Clock doesn’t work btw :wink:

Oh, and the mechanism that keeps the bonnet up is broken. Has anyone installed gas springs instead?


It’s a Jaguar gearbox Henrik, with integral Laycock de Normanville overdrive. Everything is available from specialists. You should find the overdrive only works in 4th gear. You probably have a low geared differential. To suit the smaller engine. Look in the brochure dection of the old website or buy the correct manual.

Heave fun, or at least more fun than your team had against Ukraine tonight…

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NO need for any lead additive. Any pump gas works. The valve seats are hardened and have always been. Should you find it is pinging on 95, back off the throttle and get 98 the next time. Smoke upon acceleration should be the rings and may cure itself after some driving. Add oil on the second compression test and if any definite imbalances between cylinders go away you have identified a ring problem. Congratulations on your purchase, especially with the gearbox. I like bad paint, less worries. Thank you for planning to change the steering wheel.

What do you mean by mechanism, the springs?


Thanks :slight_smile: I will update wikipedia on that :smiley:

Thanks for the advice on the engine.

The paint does its job, covering the metal from the elements, and I agree that it is one less worry when it’s not top notch :slight_smile:

There is nothing holding the bonnet up when open. Is it the Bonnet Catch Assembly? Or is that for keeping it locked when in closed position?

The series 1 steering wheel looks even better, but, I will go get the original part.

It might just need some driving to free things up a bit, as David says. After you done some proper driving have a look at the crankcase ventilation return - before I rebuilt my 3.8 litre smoky blow-by was pouring out in a stream. Just pull the hose away with the engine running when it’s properly warmed up. Perhaps drain the oil and replace with the correct grade (if have not already) - for me it’s 20W50. Well done and good luck with it - there is plenty of help here and some real gurus. Paul.

Holding the bonnet open; one bracket with a counterbalance spring and a strut at the front hinge, Henrik. It may be malfunctioning or indeed missing - take a picture of what you have got? There is a description in the Archives for fitting an alternative strut mechanism - not everybody was satisfied with the original set-up…:slight_smile:

The ‘bonnet catch assembly’ at the rear of the bonnet is exclusively for holding the bonnet down - plays no part in holding the bonnet up…

Your plan of action is spot on - but you should really get the relevant workshop manual, which also includes wiring diagrams.

xj6 85 Sov Europe (UK/NZ)

This must be the first time I’ve ever seen anyone suggest the BW autobox was in any way good or preferable :slight_smile: The old 3-speed auto is a pretty terrible transmission and the manual is a massive upgrade!


I do like my BW8!
Even the BW66 did a reasonable job because it shifted when I wanted and not when the computer calculated something. But the 66 was a real “slushbox” and didn’t feel tight enough.
The manual is a good transmission and I imagine the overdrive makes it even better still.

Pulling off the hose at the front between the cam covers and making sure it’s not plugged is a good idea, and then drive it like you stole it as soon as possible. For the bonnet a stick will do for now, I don’t know the S2 setup.

I’ll admit I once or twice drove a BW12 that felt decent, but 20+ years of driving alternately a BW66 and a MOD made me detest the automatic. With a manual, it’s a completely different and more dynamic driving experience! :slight_smile:


Rather, the tube, and also inspect the flame trap, that’s the fine screen sandwiched between the casting and the head.

Not so sure about the BW12 but the 8 has a very low stall speed so it feels very direct, not like a manual but just a hair closer. What’s not so great is the lack of top speed and increased consumption compared to the MOD.

The 8 can even be push started, like a manual :grimacing:

HAHA :smiley:

Well, to be honest, I haven’t driven a S2 with the BW autobox so my comment was ignorant :slight_smile: I have (once) driven a series 3 XJ12, THAT box wasn’t really doing the car a service, but… I don’t know… Better stop before I start a flame war :smiley: I love the manual one, I got used to it when driving home, but going into the SAAB after that was kind of strange. Like driving a toy :slight_smile:
The overdrive is great, humming about on the motorway in quite low revs. A very low revving engine, max power at 3000 rpm I think?

Thanks, the oil is 10w40 at the moment, I will replace it.

Got it! I will use this weekend to get to know the car a bit better.

Rather a red car than a red card… :grimacing:

I ordered 2 repair manuals last night, plus that I found a zip file on another forum some time back, before I got the car. Hopefully they have the proper wiring diagrams. I will take Peters advice and look at the old website also.


Heres the other one, many like these on ebay:

I also ordered new tools… Imperial sockets and so on…

Thank you all for your responses, I really like this forum.

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You’re set!

I was very much in favor of converting to a manual after my experience with the automatic in the 4.2 S3 but pleasantly surprised and tempted to leave it for now. I only sat in a V12 once, and it wasn’t running right so I can’t comment.
20W50 is the right oil, look at the price and rather change more often. Oil pressure around 40 psi at 1500+ is good (less ok) provided the sender works. Coolant at least every two years. Maximum power at 3000, I don’t think so, more like at 5000 or 5500 even. (Yes, and torque peaks at 3500)

Yes, maximum torque, sorry :slight_smile:

I found the max torque at rev spec at a site that uses the Swedish authorities figures regarding the domestic car fleet ( It didn’t have the specific number for the one I got, but for an 4.2 litre from 1974 (310 Nm at 3000 rpm).

The same site claims that the 3.4L gives 161hp vs the 4.2L 186 hp. This is perhaps not too interesting to someone living outside Sweden, but it means I can do an engine swap to a 4.2L engine should the 3.4 fail. According to Swedish law the larger engine can’t have more than 20% more hp, or more than 10% maximum torque. I don’t remember the 3.4L figure by heart, but it was within the 10% range.

Hi, I had the same problem with the bonnet not staying up and so I added a small spring to the catch just to pull it ‘over centre’ and lock it. I don’t know what the original set up was but this certainly works.
BTW a PO had installed the spring on one of the carbs as a return spring but it wasn’t up to the job so I replaced that spring (actually both of them) and I recycled one of the springs on the bonnet :joy:



So, can I swap in an engine with 15% more HP, then swap in another engine with 15% more HP than that one?

I don’t think the inspector would see the humor in that :slight_smile:

If I get an xj6 with a 2.8 L engine, this engine will limit how big of an engine I can put in the car. Even if there’s a sibling to it, an xj12 with the 5.3L. As I understand it, it won’t matter if the cars are identical in all other aspects. So, if I want to lump an old jaguar here, I better go for one with a v12 in it, thus given more room for different engine alternatives.

What you could do in theory is to ask Jaguar to send a letter providing specification of the maximum power and torque of an engine allowed in your individual car (given the VIN or something like that). Fortunately my car is from 1975, so no new emissions inspections and so on.

In Swedish:

Perhaps I should buy their book.

I asked PO if he switched the brake calipers as well, getting the ones from the V12 parts car. He said there wasn’t any difference between the calipers so he just choose the best ones.

So, is there a difference? I saw brake calipers from an xj12 that had 4 pistons. I guess stopping power is something the inspectors from SFRO will consider if I do an engine swap.

What I got :joy:

PO removed the entire thing since it broke down. So I got this stick :slight_smile:

I will go into the archives and see what I find, thanks :slight_smile:

Early saloons had 3 pistons, later had 4, I believe. It didn’t matter which engine.

I believe that came with the V12, either way, only early cars had three pistons and non-vented discs and so on. This one should have four pistons? Not 100% sure but the three pistons do quite well (they only had 20 km of driving and were ~250 daN on the better side, the S3 brakes got to 310. I am positive that the brakes have improved since, especially now that the slight pulling to the right has at first increased and now has completely disappeared). I don’t think it would matter but it shouldn’t apply anyways.

Stick will do for now. Do you have the springs and the little hinged arm on the side? I tightened the bolts of the arm and all was well.