oddbob
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- 92
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- Middleton St. George
Just changed a pair of driveshaft oil seals on a rear diff today, it was a used one I'd bought off fleabay, just thought I'd share the experience with any one who's needing to change theirs.
I'm not sure if it's possible to do them with the diff still fitted, but it's probably easier to remove the diff first, there are a few guides on how to do this on the web, but either way you need to drain the old oil.
Once you have the diff ready for surgery, stuff the roller bearings with tissues or rags to stop bits of crap from falling into the casing, and have a look at the new seals to get an idea of which bit needs to be removed, not like I did, where I just steamed in with a blunt screwdriver and got nowhere fast
Make sure you have the diff in a secure position, as a bit of nifty hammer work is involved. You'll see the seal has a flange which sits flush with the casing, I started lifting this by tapping a broad-bladed old screwdriver under it to start lifting it, then worked all the way round until the edge was lifted enough to get a bit of Plusgas in. I was then able to start levering the seal out, got it so far out then was able to knock it out with an upwardly-angled shot with the old screwdriver. When it's out, you'll see some brown sealant round the edge, the new ones have this on already, so just clean the recess out ready for the new seal. They were a tight fit, and needed to be pressed in, though I didn't have a press, so resorted to a handy lump hammer, but to use either, you need to find something to fit between the press/hammer and the new seal. I used the old egr valve off the engine (Td4), it was an exact fit, almost as if it was made for the job, though I had to turn it round so the vacuum chamber was out of the way, and placed the flanged part of the egr over the seal, carefully poking the rubber lips of the seal inside the throat of the old valve, a few taps and it was in! I left all the rags in the bearings while I did this, and will leave them there until it's time to fit the diff.
All in all, it's not as hard as it first appears, the hardest part is getting the old diff out in the first place!
I'm not sure if it's possible to do them with the diff still fitted, but it's probably easier to remove the diff first, there are a few guides on how to do this on the web, but either way you need to drain the old oil.
Once you have the diff ready for surgery, stuff the roller bearings with tissues or rags to stop bits of crap from falling into the casing, and have a look at the new seals to get an idea of which bit needs to be removed, not like I did, where I just steamed in with a blunt screwdriver and got nowhere fast
Make sure you have the diff in a secure position, as a bit of nifty hammer work is involved. You'll see the seal has a flange which sits flush with the casing, I started lifting this by tapping a broad-bladed old screwdriver under it to start lifting it, then worked all the way round until the edge was lifted enough to get a bit of Plusgas in. I was then able to start levering the seal out, got it so far out then was able to knock it out with an upwardly-angled shot with the old screwdriver. When it's out, you'll see some brown sealant round the edge, the new ones have this on already, so just clean the recess out ready for the new seal. They were a tight fit, and needed to be pressed in, though I didn't have a press, so resorted to a handy lump hammer, but to use either, you need to find something to fit between the press/hammer and the new seal. I used the old egr valve off the engine (Td4), it was an exact fit, almost as if it was made for the job, though I had to turn it round so the vacuum chamber was out of the way, and placed the flanged part of the egr over the seal, carefully poking the rubber lips of the seal inside the throat of the old valve, a few taps and it was in! I left all the rags in the bearings while I did this, and will leave them there until it's time to fit the diff.
All in all, it's not as hard as it first appears, the hardest part is getting the old diff out in the first place!
