Have him turn one output flange. Does the other turn in the same direction, or the other way. since he 'can not see" the tag, I sense a lack of trust… SAD.
Looks decent. Outboard discs. so inviting.
Open or limited slip differential?
Ratio?
Carl
1 Like
Hi,
No PWR-LOK on mine, but the 3.31 is fine, especially if you have a manual +O/D! 
Cheers!
1 Like
Right Pekka,
without doing the maths I’d guess that 3.31 + OD comes pretty close to 3.07 + BW.
Of course, the stick shift makes it a lot more responsive and competent …
Best
Jochen
75 XJ6L auto (UK spec)
1 Like
Limited slip.
3.somethin’ ratio.
2 Likes
Hi Jochen,
I only have a degree in Arts, but my maths would say:
3.31 x 0.8 = 2.648
So that’s more like 2.65, unless I did something wrong? It drops revs 20% so if I am doing 2.500rpm in top gear at 100km/h engaging O/D drops revs to 2.000rpm.
Sorry for the OP, this is a bit OT. 
Cheers!
1 Like
Absolutely correct, Pekka, from what I can oversee. I wasn’t sure about the 20 % reduction on the OD, but, yes, if it’s 20 %, then 2.65 is correct.
Best
Jochen
75 XJ6L 4.2 auto (UK spec)
1 Like
THAT low? My automatic will have to behave extremely well over the next years… 2500rpm results in under 90km/h! Not sure if that is 3.54 or 3.31, had no good chance to see the tag yet.
Cheers!
David I would say that is 3.54 diff my 3.8 ‘S’ MoD was sitting at 1800rpm @ 60mph if I recall correctly, this was with an ‘E’ C/w and pinion fitted of 3.07:1
I’m afraid you’re right. I actually think it’s too quick setting off, feels very light and powerful but not as much room for long distances 
I could do with a 3.0xx some time in the future… or overdrive 
That is a really nice clean unit @Eric318 !
1 Like
So the 15" Kent alloy wheels don’t fit (this was expected). I tried on 16" “Kiwi fruit” rims that fit well.
I guess, I now have an excuse to fit beefier wheels… 
Any one in NoCal wants a set of Kent wheels with near unused white line tires (Firestone Tigerpaw: so appropriate… 
)
Hi …
I have XJC 4.2 automatic.
I need to restore IRS. I have one extra IRS from XJ S3 (3.07 - P.L.) and IRS from XJS 3.6 manual (still on the car, I can’t read marks)…or leave original (A 75 S - 350 ) ?
Can someone explain differences between them in praksis?
3.07 is excellent and PL even better - what do you expect, what do you want from the car - speed or acceleration, race at the lights or go fast?
Acceleration is more important than fast drive…
…and is 5 speed gearbox from XJS 3.6 (1986) compatible with XJC 4.2 (1977) engine? Is very complicated to convert ?
1 . need pedals for the clutch…
2. …
.
You need a manual from a series XJ. Either the Jaguar box or the LT77. Short of that you want at least a 3.058 or a 3.31 or a 3.54 which is already a bit short in my opinion. But I prefer long legs.
A friend had an XJC 4.2 fitted with the Getrag 'box . I thought it was an S3 box, but I think they were Rover, so maybe from the 3.6 XJS. Apparently was a successful conversion.
They were originally designed for BMW, I believe. I like this gearbox, my 3.6 has it indeed with a 3.54 rear end: 2000 rpm at 100Km/h.
The S3 XJ box was a slightly uprated Rover box that perhaps had some Jaguar history before it ended up in the Rovers.