Good morning,
Has anyone replaced a pinion bearing in series II XJ6 1974. I am going thru seals quickly and feel the problem is the bearing.
Any help would be appreciated.

Jack

 

I've done it. It's one of the most challenging jobs on the XJ IRS. Setting the pinion depth just right is difficult.


That said if the bearing is real bad the pinion could move and open up the seal a bit to cause a leak. If this was the case it would be accompanied by very noticeable noise and clunks.


More likely possibility for a leak is that the seal dried out and wore a groove on the pinion that prevents a proper seal. Also Where are you getting the seal, the right seal is important. There are a few seals that will fit but wont seal. Specifically the Dana 44 seal will fit but the pinion is different on a Dana 44 so it will leak.

 

Also check the diff breather.

It may be clogged, which is common.

 

Thank you both for the info. I have had a couple of other jags and love them. This one has a 300 hp 350 chev. Currently changing the heads to 2.02 intakes. It makes a real sleeper and very reliable. I love it. I plan to get the jag on the rack this week and will check the breather as well as the wear on the shaft. thanks again.
jack

 

Icsamerica,

Do you know what seal might and where I might find one?
Thank you for your help.

jack

 

Grant, is it worth the exercise to remove that breather on Paul's car while we are lubing the shafts?

 

I beat ya by 2 years, should all be ok still.

When that cradle comes out, then do it, it is sooooo much easier.

I have only had 2 that were actually blocked. Most look quite grubby, but are still breathing fine. It is simply a "go to" item if seals continue to leak with no sign of mechanical failure to that seal.

 

I wonder if there is a sleeve solution for that worn pinion shaft. I have a vague recollection of one that slips over a bad snout on a SBc, thjus presenting a smooth surface for the seal. Or, a seal that mounts slightly different and as such rides on a part of the shaft that is undamaged.


The Off road guys have a lot of experience with Dana's of several dimensions.


Carl

 

Down here we call them "Speedi Sleeves", and that is exactly what they do.

Not sure of the market up there.

 

SNG Barret, in stock
p/n CBC6923
15$

 

Hi there! On this subject, I have an '88 V12 Vanden Plas, and I have the IRS out for brake work. When I dropped the drive shaft (pinion shaft), I had about a cup of oil, or 2 spill and I thought at the time that perhaps the diff was too full, but then I realized that if the seal was good, it should have been dry at this flange connection, right guys? So, from this post, I am wondering about the breather? I am also labouring on the decision to do the seal on the pinion, and the 2 drive shaft seals, but this looks like a tricky job with the pre-load issues. So, what do you think.....should I do the seals even though they look to be dry right now? The pinion must have had leakage along the shaft and out to the area of the retaining nut?

 

Oil out of that nut on the pinion is usually breather related that I have found, and it may have been there for years.

Oil on the outer of the seal and the flange is seal failure.

The outputs are messy and that collapsable sleeve will be needed for preload setting. If again, it is dry, toss a coin, as to do them in 12 months means cradle out again. The leaks here are usually from OLD STALE diff oil, and brake issues causing way too much heat.

Our S2 V12 at 540000kms is still on the originals, BUT, that diff oil gets changed every 2 years no matter what. It still has the original rotors and I only use Standard spec brake pads back there, none of this fancy rubbish. The park brake died 10 years ago, but the "P" works just fine, so care factor is pretty low.

Having said all that I do the output shaft seals every tme I have a cradle out. The pinion seal I have never had the pleasure of changing on any of my Jags.

 

Thanks Grant for your thoughts on this. I will have a look at the breather and see if perhaps it is blocked. As for the seals, I will have a closer look at the output shafts and the pinion shaft. They all appeared dry when I pulled the IRS out, with the exception of the pinion where the outside of the seal looked dry; thus my belief that the oil was tracking along the actual pinion shaft. My brakes were in really bad shape so there is some potential that there was excessive heat, but as the seal areas looked dry, I am trying to convince myself that the seals are ok! But then, I would hate to put the IRS back with new brakes, and develop a seal leak!

 

Grant, you stated "Our S2 V12 at 540000kms is still on the originals, BUT, that diff oil gets changed every 2 years no matter what. It still has the original rotors and I only use Standard spec brake pads back there, none of this fancy rubbish."
I have only about 140,000 km on my Vanden Plas; Does that give you more confidence that my output and pinion shaft seals may be in decent shape? Also, can you tell me what pads and calipers you use. I cannot get parts from local Jag dealer so I'm likely going to buy from Barrett's or Welsh, or for the calipers, maybe one of the aftermarket auto parts outlets, like CARQUEST or Napa. I believe the Barrett, and Welsh calipers are original Jag parts but "rebuilds".

 

Tricky job, yes. Not hard though, plenty of help given on the forum if you ask the questions as you go.
I had never striped a diff before, but got it back together with new bearings and seals on my own. 2 years later it is still working as it should and no leaks.

While the cradle is out I would recommend doing bearings and seals. I can say in no uncertian terms my leaks were heat related.

https://www.jaguarforums.com/forum/x...-115245/page5/

You can rebuild the calipers yourself, pistons,seal kit and pads are readily available. Just takes time.

 

Hard ask that, as seals are seals, and leak they will, given the smallest chance.

Our S2 Daimler went through 2 sets of output seals, same diff as the V12, so who really knows.

The Dana in my XJ-S never leaked EVER, most do, so again, who knows.

I use Lucas pads from one of our suppliers at work, and they are meant to be OE, HAHA, whatever that means 40 years down the track. OE were asbestos, that went AWOL years ago, even down here. I refuse to use "metallic/ceramic" type in the inboards of the rears, no need for that unless the car is seriously being tracked.

DB521 is the industry standard part number for the rear pads, and any supplier in the world can convert that number to their own. A standard compound general purpose pad is all that is called for.

If it were mine I would do the output seals, just coz that cradle is out.

The calipers, do your own, get the seal kits and do what is needed. HOWEVER, if the pistons are rusty, then exchange rebuilt calipers would be simpler.

The original rotor were a "sandwich" type rotor, and often pieces will break off as they wear. Replacement rotors are a solid standard design rotor. The sandwich style rotor last a long time if the parkbrake is maintained, and the standard "softer" pads are always used. When and if things fail, those rotors overheat and fail themselves, and also overheat the output seals.

Our driving is different to most, as in long haul, very little brake use, etc. We are also very meagre with braking, no real need for this last minute stand on them style.The pads in my XJ-S front have been in there for 110K kms, and are just on 1/2 worn. Different driving styles/conditions would have them all gone in about 80K kms. The rear pads were fitted in 1998, and are still just fine.

 

I am a firm believer that the "inboard brake" system is the culprit for all these seal failures on the diff.

If I drive my 86 VDP down a long steep hill using the brakes frequently to keep speed in check,.. (a lot of hills in the Seattle area), I will get the smell of hypoid fluid burning as it seeps from the axle shaft seals and the pinion seal onto very hot parts So much heat is created that it cannot be dissipated adequately and keep the temps down. That big lump (differential) is a heat sink and it takes quite awhile to bleed off heat.

I believe the heat generated by the brake caliper pad/rotor friction heats up the entire caged apparatus to the point of seal failure. As well the location of the rotors does not allow any air cooling being they are tucked up and away in the cage with hot exhaust pipes surrounding them. Who the hell invented this system ? Sheer wishful thinking.

I love the car for some of its features but (head gasket failure, tappet buckets coming loose, antiquated transmission, leaking windscreens, whooshing gas tank problems, puny handbrake, difficult to work on rear axle etc.) take a lot of the goodwill towards the car,.. out of the equation.

I have taken care of most of these issues over the years and now I am looking at this rear caged apparatus with a serious plan to correct its ailments as well.

At the moment I am collecting parts/info to switch to outboard brakes with an emergency hand brake that will actually hold the car on a hill, using small drums rather than "hope" that the clamping force of the itty bitty pads against the rotor will hold the car. Did they ever fire the guy who came up with these great ideas that do not work as anticipated?

A cooler running differential that does not have major heat sources living right next to it,...(calipers/rotors/exhaust) not to mention easier to replace the pads when the time comes ,..is what I want.

 

The heat from brakes and exhaust, concentrated in one area, can be a problem, yes. In the 60s some E-type owners solved (or at least minimized) the issue but fabricating some simple under-car cooling ducts. I think I have an old E-type book...somewhere in my piles of Jag literature...that gives the specs and dimensions.

Another idea....very simple but again could make a significant difference...is to insulate the over-axle pipes with header wrap. At least one of the heat sources would be reduced.

All that being said I've never had any significant diff seal failures on my Jags, personally. My first Series III oozed a bit but hardly worth the effort to repair. Every 4th or 5th oil change I'd use some aerosol brake wash to clean the area so as to keep oil from migrating onto the brakes. Five minutes time, once a year, seemed tolerable enough!

More rambling.....

Both personally and professionally I avoid replace diff pinion seals unless the leak is a real gusher. Re-setting the pinion nut torque is tricky. Even the pros don't always get it spot-on. Long story but years ago, when I was in the repair business, I did an informal research project on differential overhauls and discovered that more than half the diffs needing overhaul had the pinion seal replaced within the last 12 months!

On our old Jags, where the side seals also require specific bearing set-up, I'd apply the same philosophy: leave well enough alone if at all possible.

Cheers
DD

 

No need to fire anyone

The original parking brake set-up should, and will, grip quite fiercely if everything is up-to-snuff. On my XJS and Series III the p-brake would hold the car on *any* hill and even hold the car against 2500 rpm! I discovered that the p-brake pads need bedding-in just like any other pads. After that, no problems.

That using them as a parking brake. As an emergency brake...forget it !

My XJR, with outboard brakes and top-hat style parking brake is just as good. But, just like the p-brake on the early cars, the top-hat type needed cleaning and adjustment from time to time and, most importantly, regular use !

Cheers
DD

 

Doug I think that some Jags never have much of a problem with weeping seals but I would bet that they are driven on relatively flat roads. What I feel is the problem is driving down large hills, where speed is slow (always on brakes) and airflow around the cage is minimal (not much chance for sustained cooler air circulating around this shielded hot area).

Would be interesting to see stats of Jags that lived in say, Montana where roads are flat and speeds are higher vs Seattle / San Francisco type downtown area where hills are prevalent and speeds are low - in city driving.

We have a large hill in the Bellevue area where the distance from top to bottom is quite long and the road is quite curvy requiring you to be constantly on the brakes and I always smell hot vaporized hypoid smell, every time I have to use this road. I hate it.

Yes I have heard of the air scoop for the rear brakes,,,but at this time I am going to do a more permanent fix. Replace the rear inboards with outboard brakes ,,,Jaguar finally came around to this conclusion (a Ford idea?) I would really like to have a good handbrake as well. The binding action of brake shoes against the inside of a drum is more definite than hoping the little inboard pads will hold the car - they won't , at least not for long, and once the car starts rolling... So you are really betting on the parking pawl in the trans to hold the car. Then you have to fight the shifter after the car has been parked on a hill for any period of time, that is when shifter cable problems develop because the car has slipped past the handbrake pads and its full weight is resting against the Parking pawl .

I have always been taught to park the car ,set the hand brake and then put the trans in Park, so it will be easier to shift out of Park when starting off again. But with the Jag set up you end up relying on the parking pawl to hold the car stationary..