1964 Jaguar MKII rear diff

This is a simple question but I am sure the work won’t be.
I want to ‘check/rebuild’ the rear diff on my MKII can anyone point me at a video or article that would help, never done it before but a am skilled in car mechanics :).

Thanks

Gary

First step is get a factory service manual. Assuming that’s a Salisbury 4ha? Dana 44 is nearly identical, so the methodology is the same.

Part 1 of 2: https://youtu.be/qixdveMbZ9Q

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Great that’s very helpful I do have the factory service manual for the car so hopefully it’s in that as I said I’ve never attempted this before and I’m kind of a visual person I love to see things done so maybe I’ll make a video so other people can check it out that’s if there isn’t one out there already.

Thanks for the response.

I’m curious as to what makes you want to rebuild the rear differential. Of the numerous jags of this era that I have owned and friends have owned, the rear diff was probably the last thing to go wrong, but I’m sure it happens. I haven’t done the job, but I know some diffs require special tools like case stretchers. The Dana 44 that I watched getting a change in gearset some many years ago required being assembled and disassembled several times to get the gear lash right, and that was in a professional shop. You might consider as an alternative getting another used rear end. If you do the job, I’d love to learn from your experience, though.

My main reason is figuring the car is so old and I should at least replace the bearings and seals I don’t know if they’re bad until I get my vehicle back and then I can start tearing it down it’s just while I have the chance I think it something I should at least look at even if I don’t rebuild it.

Also the speedo says it only has 58,000 miles on it I’ve got a figure that’s at least 158,000 considering this lived out in Saudi Arabia it’s prior life was as a company car

Number one failure mode in Salisbury 4HA differentials -by far- is ring gear bolt failure. It is extremely common in the XK120/14/150. The bolts stretch and loosen under load, exposing them to excessive bending stresses, which breaks the bolts. If you do nothing else, check that the ring gear bolts are torqued to spec. If you find one that is loose, replace them all. Do not ever reuse the 3/8" ring gear bolts in Salisbury 4HA.

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One thing you can do is take initial measurements & observations with a dial gauge and marking compound, and if within specs and good pattern (and not leaking), put the cover back on and be happy

Mikes idea of changing the bolts is good…I had them come loose in a V12 XJ

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You can replace the seals and check the ring gear bolt torque without doing anything that would disturb the backlash. You can even replace the ring gear bolts without removing the carrier. If it is not noisy, I might be inclined to leave it be.

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if it ain’t broken …don’t fix it. A differential will usually tell you via noises if there is an issue, various whines, under load or not, etc. Plenty of info on what noise is what. A Diff rebuild is not simple…the set up is precise. If you do it…do it with an experienced advisor/helper who has done lots of em. Nick

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A company car in Saudi - the car and the story of how you came by it might be interesting should you care to share. Where is it away to now? As to the diff, if it were me, I’d change the fluid (lots of information out there about what to use), do the axle seals while refurbishing the brakes, and maybe the pinion seal and run it. If it’s loud, you will have to do the whole thing anyways.

Bearings, particularly high quality, OEM grade bearings, are made to very high dimensional standards. Among bearings with the same part number, the variation will be exceptionally small. Almost all of the shimming you need to do is the result of production variations in the differential housing and tolerances in the gears. You can replace the carrier bearings without disturbing the backlash, and you don’t really need a case spreader to do it. The spreader does make it easier to refit the carrier and side shims, but it can be done without one. A lot of the time, maybe 75%, you can replace the pinion bearings and the original shims will be in spec. If you replace the gears, you start from scratch.

My car has 42k miles on a odometer. I have the rear axle off due to complete car restoration.
I noticed about 1mm backlash on pinion, so thought - “diff. rebuild is a must”.

Was much surprised how worn were the bearings - huge pits on pinion gear bearings, also on diff. carrier.
Just bought all new bearings, new shims - as they tend to get abused during bearing removal.
And a 12T press.

I am currently writing up its adventure and will publish it in the general tab for MKII’s

As a note, be careful viewing the past with eyes from the present.

In those days cars never did 158k or traveled the intergalactic distances we do today.
100k would be an absolute rarity, 80k if lucky and considered life of the car.
Cars in the 70s never did 100k in their lifetimes like we see today.

Dunno the history of your car, but when I see these old cars for sale, much of their past was being set up sitting for great lengths of time and discovered at some point, people nowadays seem to always imagine mileage rolled over.
Not likely IMHO. Especially these old Jaguars which people loved, yet had no delaer support or mechanics had no idea how to work on. So often something happened and they just moved on and let them sit.
Side note, my father had an XK150S roadster, new.
He had to take it from his home in Rochester, New York to Ohio (or Michigan, I can’t remember which) for service!

I bought my S1 XJ6 recently, and upon receipt told it was not running well. But followed my hunch after many inquiries.
Dropped it off the trailer and simply tuned the carbs right then and there, ran beautifully.
Amazes me to this day how little understand these cars are, at least in the US.

My father tells me story other day of visiting his aunt in her huge, beautiful Buick in the 40s, and it was considered a big journey making the trip to the next town over in Ohio.
30-40min?

Anyway, fwiw
Just a thought

I watched a few YT videos about differential shimming and in my mind I’ve compiled the idea of using dummy bearings (easy on, easy off, oversize) to fine-tune required shims thickness with idea of taper-grinding the new bearings to ease press-fitment.

My idea is to use old differential bearings as dummies after slight grinding their inner & outer diameters with abrasive. I will also check precisely what is the new/old bearing difference in height, so I can compensate resulting shims for that.

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preload the old & new bearing ever so slightly in a vice and measure thickness with micrometer…you want them close…like .001"…otherwise you have to compensate… a worn out bearing is no good

be careful with the abrasive, the slip fit must be tight…any sloppiness will make it unfit for purpose

if that happens, you have to buy an new bearing and grind that