S2 Differential Pinion Oil Seal Replacement

The manual for the Ser III XJ6 and 12 is quite detailed as to these things. It describes tightening the pinion nut until you achieve the desired preload, and says nothing about a specific torque figure. I can’t really see how it could work if you tightened it to a specific torque figure.

Hi Terry…I dont know where you have looked but on the UK forum… the S2 parts catalogue in the knowledge base section gives details of the different diffs and the one with the crushable spacer…SNGB websute under S2 DHC also show details of all 3 diff types and crushable spacer…you are correct that the Jag service manual only shows the one fitted to 3.8 cars and no other info in the supplements for the later models…Steve

When I restored my late S2 FHC, I also rebuilt the type 3 differential. I followed the service manual by tightening the nut to 140 ft lbs and it didn’t come close to starting to collapse the crush sleeve. In fact, I couldn’t get enough torque no matter how much force I used. So I put the crush sleeve in my hydraulic press and just started to get it moving. I was then able to use the nut to tighten further to get the pinion drag. I don’t remember the exact value I used but I believe it was around 10 to 12 in lbs.

After I saw the service manual said only one diff was used in Ser II cars, then saw confirmation of shims for sale in the parts catalogue I didn’t look further. The UK forum search started after I looked at the on line catalogue for SNG where I saw only one diff and only shims available. Grrrr!

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Ok, lets get back to where this all started.
The question is: Can I pull the Pinion oil seal out by merely removing the nut and companion flange-----without dismantling the axle unit.
I have a later S2 which if I refer to the Moss parts catalogue is the same as the S3 diff.
Ive ordered other diff oil seals from them and they are matches to the replacement.
Secondly, their schematic also shows the use of a crush sleeve in the on the pinion assembly.

That said, what must I do to safely remove and replace the oil seal as described below? I have most tools but not a inches torque wrench. Will I need one?

Thanks for all your thoughtful insight.

Hello Terry,
Not sure what website you’re visiting, but the following picture is a screen capture from SNGB’s website showing the Type 2 differential…

Regards,

Bill

The number of ducks that would have to be in line for it to work, that the chances of success would be tantamount to winning the lottery, :hence my comment in my previous Post:

In my opinion, the whole explanation in the S3 repair manual is flawed, as there is no reference to drag on the bearings (pre-load) as measured with an lb/in torque wrench acting on the Companion Flange Nut to turn the Pinion Shaft, just a an upper and lower torque tolerance range. On some assemblies, I’ve used in excess of 200lb/ft torque to achieve the correct pre-load by measurement of the torque required to rotate the Pinion Shaft.

The only reliable and correct method is to measure the drag on the pinion bearings using a lb/in torque wrench.

The difference between the Type 1 and Type 2-3 is the position of the shoulder that resists the shims and crushable spacer respectively. I haven’t used crushable spacers in long time, due to the extreme variability of load required to crush the spacer and achieve the correct torque to rotate the Pinion Shaft.

I use a solid, Master Spacer that is over-length by 0.25mm (0.010") on the mean length, to ensure measurable end-float. Armed with the end-float value and the known length of the Master Spacer, I select a Solid Spacer of a length (from my 0.01mm increment stock) to give the correct drag on the bearings. Similar to using Shims (the solid spacer is just a very thick shim), it can take a number of assemblies and measurements to get it right. However, I’ve been doing it this way for so long, I get it in one assembly for measurement with the Master Spacer.

Regards,

Bill

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Bill,
The illustrations and 120-140 torque spec are for the output shaft bearings, not pinion.

Hello Thomas,
Establish small holes, relative to self tapping screws used and arrange a puller in combination with self tapping screws to pull the seal out. It would be better to punch small holes with a sharp pointed punch, rather than drill them, thus avoiding contamination via swarf from the drilling operation. A drill can be used to start the process to make penetration with the punch easier; just take care not to go right through with the drill.

Depending on the arrangement of the puller, it may be better to weld self tappers to the end of Threaded Rod to get length.

If a lb/in torque wrench is used you need to be only measuring the drag on the bearings in the back lash zone of the Pinion and Crown-wheel. It may be safer for you to just mark the position of the Companion Flange Nut and replace it to that mark.

Regards,

Bill

Not so Robert. You need to put your reading eyes on. One clue, but not limited to, is the reference to replacing the collapsible spacer. There are no collapsible spacers on the Output Shafts; only the Pinion Shaft. Another is the reference to Companion Flange Nut; there is only one coupling of a differential that is referred to as a Companion Flange and that’s the one that interfaces with the Pinion Shaft. A third is the reference to rotating the Companion Flange to ensure correct seating of the Taper Roller Bearings; no Taper Roller Bearings involved with the Output Shafts of the differential used in an S3 E Type.

Regards,

Bill

As per my previous answer

I have done 2 seals from a Diff this way, this one is an auto trans front main seal

just start with one hole, a big tight seal like the Pinion seal may need 2

Bills method of making the hole with a punch is good

My understanding of the Pinion Nut torque is it will correctly “stretch” the Pinion nut thread so that helps maintain the pre-load, if it isnt stretched, the nut will work loose, and the pre-load will be lost

a Dana 44 has a Pinion nut torque of over 200 ftlbs

Hello Tony,
That’s exactly correct, but the 140lb/ft torque specified in the S3 Manual is far short of the torque required to use the natural elasticity of the Threaded Journal to keep it tight; it still requires a Steel Locking nut to ensure it doesn’t come loose; in excess of 200lb/ft would be in the area. Typically, 200+ lb/ft torque is required with the collapsible spacer to get the correct drag (pre-load) on the Pinion Bearings.

Regards,

Bill

I dont see it mentioned, maybe it has been

but you are not supposed to re-use a Pinion Nut (for the final replacement)…“one use”

If you use the old one, it will be stretched, and just makes the whole thing out of spec

I had one work loose once

My understanding even Loctite wont prevent this, but it is often recommended, and would possibly stop the nut falling off, (they make noise first)

At this stage in my learning, I would order a new pinion nut

Hello Tony,
Yes, its a good point to mention. Things that are habit can go unsung. This also makes the reference to a 120lbft to 140lbft permissible torque range specified in the S3 Manual even more absurd. There is quite some torque required just to set a steel lock ring nut.

When setting the pre-load of Pinion Bearings using shims, an ordinary nut should be used during the pre-load measuring stage and then a new lock nut for final assembly.

Regards,

Bill

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I have never tried to do one with a crushable spacer, too scared

Only needed one doing, got a pro to do it

From reading on this and other forums & sources, the initial torque to start crushing the spacer was very variable but always over 300ftlb, and sometimes up to 1000ftlb, and that once that crush started, the force would reduce, while continually checking preload, till it was correct, then (I presumed) tightening the Pinion Nut to the specified Torque ?

sounded nasty, have heard of the solid spacer kit before

I have read some conflicting information, including one guy who reckoned he restored his lost pre-load in a spacer Jag Diff by adding a pre load shim ?

Both Dick Maury and yourself have proven imo to give 1st class advice on diffs

Wrong. Look at the illustrations. Also, the later do indeed have collapsible spacers on the output shaft; I just did mine on my XJ-S.

Im now comfortable that I can remove the seal but after reading all the various threads am completely befuddled as to how to proceed with a reassembly. Preload, tighten to 140 lbs ft, mark the pinion and nut and reattach the nut to align the marks, old nut, new nut etc. etc.
Can we clear this up?

Perhaps you hadn’t noticed, but this section of the Forum is on E Types and in particular, this Thread is on E Types, not an XJS.

You really do need to put your looking eyes on. My Post #17 is an extract from an S3 E Type repair manual and the reference to the 120 to 140lb/ft torque is for the Companion Flange Nut; it states that quite clearly in the text. The actual correct torque, as specified in the repair manual, for the nut that you’re referring to, is in the range of 90 to 110lb/ft

No differential used in an E Type assembly used collapsible spacers with the Output Shaft Bearings. S1 E Types and S2 cars equipped with Type 1 and 2 differentials used Taper Roller Bearings in the Output Shaft assemblies, but a solid spacer and shims were used to adjust the bearings; nut collapsible spacers.

Type 3 differentials, the most common differential used in the S2 and all S3 E Types, used a Double Row, Angular Contact Bearing manufactured by Hoffman (see the pictures below of the original Hoffman Bearing in the disassembled and assembled state) This bearing had a split inner race, that when assembled with minimal end pressure exerted, there was clearance between the inner faces of the inner race. When the securing but was tightened, the two inner faces come together to result in a predetermined, correct pre-load. The correct torque for this nut, the one you’re confusing with the Pinion Companion Flange Nut, is in the range of 90 to 110 lb/ft.

The original bearing has not been available for many years and the usual After Market Jag parts suppliers, supply a replacement bearing that is the same OD and ID, but 2mm narrower. Two, 2mm wide spacers are supplied with this bearing, one for the outer and one for the inner race. This bearing doesn’t have a split inner race, has no pre-load and there is no scope to pre-load the bearing. Accordingly, its a poor substitute, but better than nothing.

From circa S2 XJ6, Salisbury differentials reverted back to opposing, taper roller bearing for the Output Shafts, first using solid spacers and shims and then later to collapsible spacers.

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Hello Thomas,
If your differential uses a collapsible spacer (most likely in an S2), mark the position of the nut, replace the seal and tighten the nut to the same mark. Use a new, steel lock ring nut, as there is probably not enough torque to keep it tight and the locking nature of the nut is required.

Don’t just tighten the Companion Flange nut to 140lb/ft torque as this may be too much, or not enough. This can only be determined by using a lb/in torque wrench, or some other means of measuring torque, to determine the torque required to turn the Pinion Shaft. This is normally done with only the Pinion Shaft and its bearings installed, and is easily done. With the differential assembled, you can only make that test in the area of backlash between the Pinion and Crown-wheel.

Regards,

Bill

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Wrong- look at the illustrations you posted - look at the orientation of the ring(crown) gear and the differential side bearing. You posted a picture and text of the output bearing preload setting.
I don’t know or care whether there are differences between the E and XJ-S; I am pointing out that you are referencing the wrong procedure for the pinion seal.
That said, you could probably remove and replace the pinion seal, and as long as the collapsible spacer doesn’t compress further at that torque, you might be ok. I would think it would be better to under torque with lot items than to exceed the preload.