1971 S3 stub shaft bearings

I’m in the process of reassembling my 71 Series 3 IRS. One “must do” task has been to replace all of the seals in the differential. Simple enough. I am not sure what type of differential that I am dealing with here. I will post some pics later when I get them on my site.

I pulled the stub shafts out yesterday (keeping everything clearly identified) and found that it used 2 row ball bearings. I have also seen chatter on here on some other threads regarding the 2 row ball bearings as being inferior. I’ve not checked end float or anything like that as of yet. It is all a work in progress ATM.
In looking at the Jaguar factory PDFs, they only show a standard looking bearing part# 12261 in this position. From the usual suspects, it comes with shims.

So, are the dual roller bearings that prone to wear or failure?

I am sure that there are more questions to come.

Are your output shafts held in place with 5 bolts? Do the brake calipers mount to the output shaft flanges?

Hi John…plenty of info on the forum if you search …Diff output shafts…here is a copy from a post relating to the double row bearing you refer to…As far as im aware the double row bearing is not inferior…note this bearing is no longer available and the replacement from the usuals needs shims…

"Later E Types had a Double Row, Angular Contact, Ball Bearing race that had a split centre race. This system provided bearing preload when the nut securing the bearing was tightened. This bearing is no longer available and the replacement is less than totally satisfactory in my opinion. The replacement is 2mm narrower (27mm), requiring two, 2mm thick spacers, and has a one piece centre race with no scope to preload the bearing.

The output shafts and bearing housings from an S2 XJ6 are interchangeable with the E Type parts and have opposing taper roller bearing where the correct setting is facilitated.

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Hello John,
As Steve wrote above and I believe that may have been an extract from one of my Posts.

The original bearing was double row, angular contact, ball bearing race, where the centre race was split in two halves. Preload was built into the dimensions of the bearing, so that when the two halves of the centre race were pressed together until their inner faces came into intimate contact, the correct preload was achieved. This is a good system, but sadly, this bearing has not been available for a long time.

The only replacement available is a double row, angular contact bearing, but without the split centre race and prelaod is not possible. This bearing has the same OD and ID as the original, but is 2mm narrower (27mm instead of 29mm). Of a consequence, two, 2mm thick spacers are required. These spacers have to be assembled with the outside faces of the bearing, in itself is not the most desirable configuration. I’ve looked at trying to install the spacer for the outer bearing with its inside face (only one spacer is required in this configuration), but the “O” ring in the bore of the diff housing is in the wrong position relative to the actual position of the inner end of the bearing. I’ve also looked at cutting another “O” ring groove further towards the outside, but the major diameter of the groove would come too close to the outside world, due to the outside cast profile of the diff housing.

The only options you have is to go with the replacement bearing, along with the spacers, or replace the output shafts and bearing housings with those from an S2 XJ6 onward, or XJS Salisbury differential (not Dana).



The other option, of course, is to inspect the double row ball bearings for wear, and if they are not worn, reuse them. This is what I did on my S2 diff which had this bearing set. 25K+ miles later it keeps on going. I just replaced the output shaft seals, and pinion seal, and checked the backlash before reassembling.


check out my youtube channel Jag Mods.
I don’t have an e-type manual but I do have a XJ Series I manual. Knowing how Lyons and Jaguar and the BL monstor operated in the 70’s more the parts are probably the same. '71 Salisbury diff. I’m rebuilding a '74 Salisbury powerlock. I’ve already done the output shafts in the videos

Hello Mark,
The output shaft bearings for all S3 E Types are different to those shown in your video. The taper roller bearing system shown in your video are the type I referred to in my earlier Post as an alternative (and an upgrade) to the Double Row, Angular Contact bearings used in the S3 diff. However, to upgrade, the output shafts and the bearing housings/brake caliper mounts from an S2 onward XJ6, or XJS have to be obtained to replace the original E Type equipment. Its all or nothing.



Hello Mark,
I watched your video, and with all due respect, how does 0.006" end float equate to Pre-load? My definition of Pre-load to the lay person is less that no end float. When the Taper Roller Cone comes into intimate contact with there respective Cup, there will be Zero end float, but also, Zero Pre-load. Its only when you go past that point of Zero end float that the bearings are under Pre-load.

The fact that you are able to turn the Output Shaft with the torque limiting driver set at 3.98lb/in doesn’t really indicate Pre-load. You would want the torque limiter mechanism letting go at the required torque setting. Back the bearings off to 0.040" end float and the output shaft would still be turned with a torque limiting driver set at 3.98lb/in.



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Hmmm… Sorry about that. You’re right. I took a look at the XJ Series I manual and it has pair of ball bearings and not the tapered roller bearings that are in the video. The diff in the video is a Salisbury Powerlock 3.54:1 ratio. I didn’t think about
my post to your thread until after posted it and thought about it a bit more. Sorry.

Is the IRS your working on a Salisbury Powerloc? I’m assuming it’s a Salisbury judging by the age of the vehicle. When I took mine IRS apart and looked at the wear, all of the sub shaft bearings had signs of, what I’d consider abnormal wear. The races
had signs of abrasive wear as did the bearings. Not to overstate the obvious along with the abnormal where there was signs of some significant heat happening too. All of the races were a blue color as were the bearings ran. This tells me these bearings got
hot really really hot like around 800 deg F hot. . The same with the bearings they were blue too. I’m pretty sure I showed that in the tear down video. My point is this if it’s a power lock, there’s going to be more bearing wear than normal on the bearing
surface because you’ve got friction material floating around the oil coating all that the oil touches. Causing abnormal wear patterns on the bearing and mating surfaces.

With respect the the brakes and output or stub shaft I believe they are the same salisbury 5 bolts holding the stub shaft in place and the brakes calipers mounting to the stub shaft outer bearing housing. The XJ-S is a whole different story. They use
a Dana44 diff the output shafts are different, the pinion shaft were the diff connects to the drive line is also different Salsibury round with 4 bolts, dana44 square with for bolts.

3 bolts holding the stuff shaft housing in place and the brake rotors are different as well. I also covered that in one of my videos. Different types of brakes on an Jag. Mostly covering the old stuff. Pre-Ford.

Here’s my thoughts on the roller vs tapered bearing. Yes tapered roller bearings do wear beater than ball bearings unless completely sealed. Due to the smaller contact area (smaller than a tapered roller bearing) there will be more force on a smaller
area. Granted this is compensated for by having more balls in the race / cage. If you’re considering changing to a tapered bearing. I would think it would be doable – providing the bearing dimensions are identical. And using a crush sleeve between the two
bearings to assist in setting the bearing preload. Bearings are like legos purchased from a specific manufacturer(s) based on provided dimensions. For example, the tapered bearings in the carrier are the same front wheel bearings for a Triumph Herald, Spitfire,
and MG Midget. The outer stub shaft bearing if memory serves is the same bearing as the front inner wheel bearing on a mid 60’s GMC / Chev pickup truck.




I typically don’t venture into the E-type forums because; well you guys appear to be much more serious than us humble XJ Saloon guys. Sorry If I’m not of much help.

Hello Mark,
Dana diffs in the XJS were only used for a short period; they also used Salisbury diffs.

Converting to the opposing taper roller bearing of the Series 2 and later XJ Series and XJS with Salisbury diff, is totally doable and the bearings are not within a bull’s roar of being of identical dimensions. The whole bearing carrier is different, but the diff housings are the same. To make the conversion, simply unbolt the Output Shaft/Bearing Housing assembly from the XJ or XJS ( Salisbury diff) and assemble them with the diff housing of the E Type.

With regards to the crushable spacers, the earlier XJ Series that used the Tapered Roller Bearing System, used a solid spacer between the bearings. Correct Pre-load was achieved by using shims to result in Zero end float and a specified torque to be able to set in motion and maintain the rotation of the Output shaft.

I still don’t get how the 0.006" end float shown in your video, translates to Pre-load. Taper Roller bearings prefer to be in Pre-load than running with end float and actually heat up more with end float, than with correct Pre-load.



The Salisbury output shafts tapered bearings require Pre-load.
Setting them with End-float is not correct, Mark’s video is erroneous…

Wow! You’re absolutely right about the preload. For what ever reason, there’s a bit of the video that ended up on the cutting room floor, that would coincide with what your statement is and what I did. I will put a follow up video correctly
stating what I was trying to get across. Wow! No wonder I don’t have very many views – I look like a complete idiot. This is what I was trying to get across, but clearly didn’t.

The .0006 doesn’t translate to preload.

The I was following the manual where it says take up most of the slack then tighten in increments to essentially set the preload on the bearings. The preload is measured with the rotational resistance measure by the torque limiting screwdriver
and the abomination welded together necessary to actually use the torque limiting screw driver.

After your comment as well as Aristides, I watched the video again only to discover I look like a complete idiot and the point I was attempting to get across is gone. Essentially the video clips are out of sequence. I’ll put something
up to fix the error.

The steps I was trying to put across is

Kibert, yes, the plate for the output shafts has 5 holes to mount to the differential and 2 threaded holes for mounting the brake calipers.

In looking at the races and bearings, they are in extremely good shape so I’ve reassembled them and will be bolting them back in place here in a few days.

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Hello Mark,
That was my point with regards to the 0.006" end float. But also, the way you tested for Pre-load with the torque limiting driver is flawed. Your test would have passed before the securing nut even made contact with the Tab Washer. You need to tighten the nut until the torque limiting mechanism lets go. There is a tolerance range for the torque for testing the Pre-load. Set the torque wrench to the mid of the range and proceed tightening the nut until the torque wrench barely fails to turn the Output Shaft.



The video is flawed. I’m in the process of replacing it. I found the actual footage. Parts are missing cause the camera wasn’t recording when I thought it was. Especially the bit when testing the preload with the securing ring bent over the nut. I realized that bit was missing; I was all out of output shafts apart; and I wanted to show how to test the preload.

It’s funny how after you don’t look at something and the pretense is no longer in your head; and you can see how the point you where trying to get a cross is completely lost.

thank you Bill for pointing that out.


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