Gearbox on my series 2

Hey everyone e just wondering if anyone can forward me to any info on better auto boxes for my 4 speed auto as I was wanting to make this be a better car and I was thinking a five or six speed box mated to my 4.2 engine would make it a far better car and does anyone know if my Xj6 series 2/3 lwb 78 will have a lad on the back end any information would be a great help and thanks again for everyone’s help and information in the past also does anyone know anyone who has or is or does restore old series 1 and 2 xj in Scotland

Harry what lad on the back end? The diff should keep up there was a page on the old forum with gearbox conversions done before, for autos you want one that doesn’t have anything digital or god forbid electronic valve switching. 4speed is at good as it gets, perfect if you have a lockup converter. Overspeed high would probably do much, or a low 1st and a 2.88 diff from a v12 (for the powrlok). E type drivers prefer a 3.07 final as ideal if that helps.

5 or 6 speeds are hard to get with autos. Look at the old forum xj page. Check out rust2rome if you haven’t, not for restaurations but literally anything else but; on YouTube.

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Just curious which 4 speed auto you have in the car now?
S11 came with the 3 speed only or 4 speed Manual.
And clarification on ‘lad’ for the rear end?

Unfortunately I don’t know which box she has she’s a project but I want to make a daily driver and it’s just the standard diff that came out the factory and does anyone have any 4.2 straight 6 engines for sale. It’s a 78 with a 4.2 engine with hif carbs but she’s a rare one as she came off the pi line but got carbs fitted

It’s original, then it has a 3 speed. Leave it at that. Get her running.
Scotland, many engines to find but this forum probably not so much.
There’s a tag on the diff that gives the ratio which is what I‘d look at first. Transmission is a lot of trouble and time.

I’m good with boxes mate but just wondering is the original torque convertor good match to the car and also I having bother getting her started got her to pop a few time but she won’t fire it’s a project rusty but welding back together but due to that I bypassed the ranks a fuel filter and lines blew the carbs apart and most of the lines connected and the diaphragm but when I hook fuel up to her with a pump she just spins and doesn’t fire i was wondering if there are any common faults that will cause this to happen

I ment lsd mate on the back end

TC: good enough match.
If it pops that is good in a way, check timing and try starting fluid after a few cranks. That is if the carbs are okay. You do have the correct pump I hope. Common faults are too many to list, work your way through what seems wrong and go again.

Lsd makes so much sense: if it says P/L on a tag on the diff case or the wheels don’t spin in opposite directions when you turn one then it’s a LSD.

Should it ever move under its own power you‘ll have three speeds. 4 ½ (with lockup) is what might go in, 5 or 6 unlikely.

Well it’s a fuel pump that I stole off my dad’s series one jag project but what are a couple main ones for it

Should be fine then if it just pops but doesn’t really go and it’s not a backfire then not all cylinders work and so it won’t catch could be anything if it has decent compression and spark on all cylinders it can really only be mixture timing or it doesn’t want to go just yet best bet make a list and check everything thats what I do

Aye I just this is my first project fixed a bunch of cars but nothing this old so lack some information so I’ll check.timjng and do I need a strobe light to set the timing or does the Haynes manual say how to set the timming

Haynes will have the base setting method for static and a you can use a strobe light for fine tuning. You might want to do a leak down test and compression test just to see what the overall state of health the engine is in.

Which should work if you have carbs, Harry…:slight_smile:

xj6 85 Sov Europe (UK/NZ)

Which is what I’ve got a pair of hif carbs

I think the 3 speed auto in these is these cars biggest bug bear. Crappy shifts, rob heaps of power. I’m currently looking at a conversion to a 4 speed ZF conversion with lockup converter - would be a much better car with this IMO. Long term project as I’m just enjoying the car for now, but the Borg Warner box will go at some point.

I have a spare ZF4HP22 that’s almost brand new sitting under a bench in the garage - at some point I’ll pull the driveline and see what I need to do to glue that on the back of the engine.

Popping could be plug leads mixed up. Are you certain the firing order is right for an anticlock dizzie?

hey peter been busy and aye leads should be good and compression appears okay just turning over no fuel getting a good consistent pu pu pu and that’d be right as the pistons go in pairs if I remember right, I did forget to say that even after I blow the carbs apart and the diaphragm cleared all the pipes I was only getting bangs after I have dropped fuel in the bores so I’m just waiting to get paid and get oil for the carbs finish building the exhaust back up and try again. I did do the timing to the book (Haynes manual) and my dizzy only goes on one way. To break down what I done I got leads for it plugs changed the points to solid points I didn’t bother changing the arm or dizzy as they appeared okay. so my only other thoughts are its not got enough fuel going through so maybe a blockage in the inlet manifold but other then that I’m out of ideas. Also I had my old man hold the carbs open to get air down the bores and I used easy start as well as fuel

If it doesn’t run on all 6 on easy start remove the plugs, all, set the frontmost on tdc compression and look at the damper at the front of the engine. The pointer should point to 0°. Now rotate the engine to 6° btdc or whatever your sticker says, and turn the loose distributor until it sparks/the points open. Centre lead should bridge half an inch or so to ground.

Now verify spark timing. I assume you made sure that your dist shaft doesn’t wobble around like crazy or is no longer straight. you said its okay. If it doesn’t run on easy start after that something should be odd. Cam timing or absolutely no compression did it run well before?

ill give that a try like and the shaft was tight no slack in it at all spins good a free and I tested the spark on all the plugs and all have consistent strong blue spark as for whether she ran before not a clue but with plugs in or out she spins freely and I hear and solid 3 sets of pu pu pu in pairs so I am assuming compression is okay. Il check if I wrote this up on my profile but my series two was to get used as a parts car as there is about 6 months straight of welding needing done but I would make my life easier if she rolls under her own steam and it would let me know that the engine is okay and it isn’t just a shell. when I dropped fuel down the bores and put the plugs in she did bang (I think in all 6 defo in 5 I know for a fact) more then once with I fuel supply added but she just wouldn’t fire, I was only the manifolds that where on when I tried to start her as I was needing the down pipe to finish repairing the intermendiate pipe.

The Story is I was doing working for a guy looking at doing a back end swap on an old van to stratech the chassis on a old falt bed the work never happened as he never got the engine pulled forr the old van to go into the flat bed so the diff and engine would still match up, I ended up doing an altenator on a alfa and a head gasket on a Peugeot and a couple oother things but I asked HIM IF he was selling anything or looking to sell anything guy had pills of cars but he needed to get most of the cars shifted before the crusher came bust he said he had a couple old jags and he said that he had a guy with a series one who wanted to put a manual box into the series one and I think put the back end from the series 2 into it or maybe just the 4.2 engine im assuming the conversion plate for the 2.8 engine would go onto the 4.2 engine but the guy never paid for the labour bill so the guy doing the work took both cars (the 71 2.8 xj6 series 1 and the parts car which is a 4.2 78 series 2 off the series 3 line with the PI badge on the boot) to offset the cost but my old man bought the jags as a pair a grand (£1000) for the series one and 100 quid for the series 2. my dad said if I gave him the 100 for the series 2 then I could have it and do the work and mostly got the box of the shell secured and the work is getting there.

Well with compression and spark at the right time and on all you will have to check the carbs don’t know what to do there but I guess it’ll be the usual check needle floats fuel in the bowl and damper movement etc. maybe theres troubleshooting in the manual which I hope you can have else I can mail you some relevant bits.

Do I get you right the 78 was built on the PI line but did get factory carbs… as in the US models all had FI already but this or other home market might have gotten the rest of the carbs.