XJS 1993 4.0 overall gearing

Hi Guys,
Can anyone tell me the overall gearing of a car fitted with the 4HP22 trans? I can see that the diff is 3.54, so presumably 4th gear is an overdrive.
And does the torque converter lock up in 4th at 50 mph or so, like the XJ 300?


Your diff is GKN i assume, have a look in the repair manual - you will have full info in the spreadsheets.

Yes, TC locks up at 50mph

Gearbox and ratio - it seems you should have 4HP24 instead of 4HP22. Same as above - in the spreadsheet. You will be more lucky having 22 version of course. Check if you have wiring loom coming out from the housing behind gear selector input shaft.

Thanks, Janusz. Well, I don’t actually have a car at the moment, but have the chance of an XJS convertible and an XK8 conv. Trying to make up my mind which to go for, and overall gearing is a factor. Yes, you’re probably right, it probably has the 4HP24…


Out of pure curiosity, why gearing makes the important factor? Both deals are taking convertible models into consideration. With this type of design - gearing goes into deep background… Driving experience will vary with roof extended/folded. Another thing affecting shifting will be long-term weather conditions - both XJS and XK convertible can take approx. 2 full-size garden water butts of weight during the rainy season, that’s before driver will notice the smell of damp/wet sandals…

Well, I prefer cars that have high gearing, more relaxing. But that water butt info is really useful - thanks! :grinning: Reminds me of a selling point for the Leyland P76, in that the trunk would take a 40 gallon drum with the lid closed.

Completely different animals Anthony, and far far appart as the XK8 was designed quite a few decades later than the XJS, and by a different ownership on plus.
Overall gearing I think it’s the last thing you should be preoccupied with.
Age and overall condition instead me thinks.

Do you do the work yourself?
If not the XK8 is the winner.
Also the V8 has heaps of torque, the car is lighter, and will definitely be more relaxed on the highway in terms of engine revs, but not remotely as comfortable and spacy as the XJS.

And also, as far as looks, class and personality are concerned the XK8 can’t even start to compete with the XJS…

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Belated thanks, Aristides ! Well, I have made the choice - '93 Solent Blue XJS 4.0 convertible. This seemed to me to be the sweet spot of the range - facelift but without the fragile plastic bumpers and useless rear seats.

But there’s a limp-home issue to sort out, taken into account in the price - hopefully just a sensor or something.

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