HOW TO: Replace diff pinion oil seal on rover axles

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Replacing a diff pinion oil seal on Rover axles.


First take out the fill plug for your axle (just to check it will come out!) then take out the drain axle and let the oil drain into a suitable container.

Then remove the propshaft by undoing the 4 bolts holding it to the diff output flange. I found a propshaft tool wasn’t that easier than 2 spanners to be honest. Tie it up securely out of the way.
You should then see this, straighten and pull the split pin out.


Undo that big nut, it’s a 1 inch jobbie and should be farking tight. I used a big breaker bar and a wrench on the flange to hold it still. DO NOT tug on it if you have half the vehicle on axle stands as tugging this nut causes the vehicle to move and it could come down on you head and kill you. I had all 4 wheels on the floor for this, wheels chocked.
When the nut is off it will look like this


Pull of the drive flange, it should come off by hand, if not encourage it with a rubber mallet. Make a note of the order of any washers/spacers that come off with it. Now you can see the drive splines and the seal itself. I have lots of splines, some people might only have 4 chunky ones. That’s fine. My seal looks ok but the inner lip was quite worn. Have a look at your drive flange you just removed, make sure the surface the seal runs on is smooth and clean, if its pitted or ridged it will need replacing.


Now prise the seal out being very careful not to scratch the surface it mounts against. Some people have issues with this but I found a large screwdriver popped it out easy enough. Wipe down the faces and splines, I greased my splines with ep80/90 grease as i love nothing more than slipping a flange onto a greasy shaft (snigger snigger)


Its also worth checking the outer bearing at this point, so gently wiggle it out taking care to note how many spacers/shims there are and the order they go in. This is vital for reassembly to get the preload on the bearing right. Some more modern axles have a crush washer to set the preload. I don’t know about this but have been told that the easiest way to sort that is to mark the pinion nut before you remove it and then count the number of turns it takes to get it off, then put it back on the same number of turns till the marks line up. I don’t know, research this before you pull your landy apart! If you have the shim system then just replce the shims in the right order and torque it up correctly.


My bearing was fine so I greased it again and popped it back in with all its shims


Then I carefully drifted the new seal in till it sat just slightly below the surface of the flange it is going into
NB. If your new seal has the raised centre lip like the one that was removed, this raised centre lip MUST be level with or below the axle casting or it will be destroyed by the drive flange. If it isn't already, grease or oil the inner faces of the seal so that when your first drive it, it doesn't run dry for the first few hundred metres.


Replaced the drive flange


Put the nut back on, torqueing it up to 96lbs/ft and replacing the split pin and then re-connected the propshaft using new nylock nuts and bolts.



Its worth at this point checking your axle breather, undo this banjo bolt and check the breather is clear by blowing some air down it. If it is, great. If it isn’t then replace it of unblock it. A blocked breather will just make your new seal leak again as the pressure in the axle rises it forces oil out around the seal.



Then when you have done all that, refill your axle with ep80/90 (upto gl4) 1.7litres until it dribbles out the filler hole, then take the rover for a test drive and observe for leaks.

Hope that helps some people, this just took me around 1.5 hrs in my garage with normal tools.
Ed

EDIT: Apparently I have made a slight mistake by fitting the incorrect seal as I have the later mudshield. The problem is with the early seal and later mudshield ,is the later type mudshield will rub on the early type seal. Land rover sorted this my introducing the later seal that sits further in and is thinner and has a raised lip for the later mudshield to run on.

If you push the early seal (frc8220) in too far to compensate for the later mudshield, the seal lip wont engage the flange properly. The early seal is frc8220 and the later seal is ftc5258.#

Now I hadn't noticed any problem with mine (yet) but it would be prudent to fit the correct seal for your mudshield! Apologies everyone! Thanks to jamesmartin on Landyzone for pointing that out to me, of which I was unaware.
 
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no probs, i did this a couple weeks ago but only got round to putting it up now. Interestingly my diff still leaks slightly but not from the nose, it leaks from the bit where the diff bolts into the axle!
 
Changed my rear diff pinion oil seal last weekend. Although mine is a 95 Tdi 300, it has the 2007 later diffs fitted.

The oil seals are different on the later diffs and I bought the wrong one to start with. When taking the drive flange off the pinion, the seal appeared to be knocked into the diff housing too far, and the main band of the seal was not really sealing. With the new seal tapped in short of the step in the housing, the seal on the drive flange is now oil proof and has not leaking.
 
the seal you used is frc8220 and isnt the right one to fit the mudshield on flange ,it should have ftc5258

Yeah I know but it goes in the same, I have written how to fit both types though.

What do you use to get the part numbers? I just went to my local motor factors and ordered a pinion oil seal and that's what I got :shrugs:
 
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Yeah I know but it goes in the same, I have written how to fit both types though.

What do you use to get the part numbers? I just went to my local motor factors and ordered a pinion oil seal and that's what I got :shrugs:

ive built that many i know them off by heart ,the problem is with early seal and later mudshield ,is shield will rub on seal( iknow from experience ),later seal sits further in and is thinner and has a raised lip for the later mudshield to run on ,if you push frc8220 early seal in too far to compensate for later mudshield,seal lip wont engage flange properly
 
oh right, i cant see it rubbing, there is a clear gap between the mudshield and the seal, its not big but its there and its not leaking at all ??? if it fails no biggy i shall just replace it.

Can i pinch part of your post to update the thread please?
 
Cheers for this. Noticed today my front one is leaking, but I think only on longer runs in warm weather. The rear also leaked a little and hissed as I undid the fill plug so will check breather first.
 
I always wondered why my engine smelt of EP90 when it was hot until i noticed yesterday where it has sprayed all up the side of the engine from this seal.

Bring back winter when its cold enough for the oil leaks to stay away!
 
Ashcrofts sent one of my lockers back with an early flange dust shield & seal fitted, can one simply take off the old flange/ dust shield & fit a new seal and flange kit.
Cheers.
 
Ashcrofts sent one of my lockers back with an early flange dust shield & seal fitted, can one simply take off the old flange/ dust shield & fit a new seal and flange kit.
Cheers.
you could fit frc8220 seal to go with earlier mud shield or swap mud shield, you can remove swap flanges ,pinion bearings are shimmed so you cant effect the pinion bearings etc by retightening the nut
 
Will remove the old flange & seal and fit Stc4858 kit same as my rear casing that covers the seal from mud the best.
Thanks James.
 
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