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Discussion Starter · #1 · (Edited)
Many of us suffer from a weeping diff.Usually it is the input shaft seal leaking.

There is two ways to do the job.

Either take the differential out or take the propshaft out.

In case the exhaust is already cut somewhere,I would go for removing the part under the differential,disconnect the drive shafts(Torx E14,tightening torque 83NM),remove differential oil(14mm inhex socket),disconnect the prop shaft(16mm socket,tightening torque 70NM),floor jack under the diff,remove the bolt of the front mount(21mm socket and spanner,tightening torque 150NM) and the bolts of the rear mounts(16mm and 18mm socket,tightening torque 105NM).Note that installing the diff,first tighten down rear bolts,then front bolt.
Now it's time to pressure wash the whole thing,just cover the inside of the input flange.

If the exhaust is still stock one piece,has to be dropped completely.Then the propshaft removed.Perfect time to throw a new guibo and propshaft center bearing in...


For both cases,clean the nut in the propshaft flange and mark the position of the nut to the flange(important not to overtighten during assembly because the tension of the nut is responsible for the input shaft bearing)






Remove the nut with the impact wrench(32mm socket) and remove the old locking plate of the nut(replace with new one).
Clean the inside again to mark the position of flange to the shaft.


Use mallet to remove the flange.


I take now a screw driver to pull the old sealing out.Clean the contact surface,oil the new sealing and drive it with a socket with large enough diameter in.



I usually replace also the dust cover of the flange with a new one




Install flange(pay attention to the marks) and tighten the nut to the mark.Push the new locking plate in,use the 32mm socket and the mallet to force it in.


Assemble everything,diff oil in,get a beer...

If anyone is interested,I write a full DIY how to rebuild these differentials as I have one to rebuild in a few weeks...
 

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Superb, thank you vantam5.
This is a job I'll need to do very soon on mine. I'm also going to be changing the handbrake cables and it's very likely that the propshaft bearing will need to be renewed too (getting some light vibration in the cabin). I may well finish the job off with new prop rubbers (guibos), everything will be nice and fresh after this and all done in one job.
 

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Excellent thanks brother!
 

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I should have added this earlier:
I've also heard that a leaking prop/diff seal is a good indication of a worn prop bearing - the additional flexing and vibration 'hurts' the seal causing it to eventually leak. A minimum of a thorough inspection of the bearing should be done if a seal is being replaced. If you're not DIY'ing it then the additional cost of a new bearing is pretty small compared with the cost of fitting it at a later date so it may well be wise to have it changed along with the seal.
 

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Discussion Starter · #11 ·
Question: If you are disconnecting both the input and output shafts, why not remove the whole differential and fix it on the bench?

If you read my DIY again and look at the pics,you will see that only the input shaft is disconnected.

I write about removing the whole diff also as second option.

In this case I had to remove the propshaft of the car anyway to change the center bearing.So the diff stayed in the car and I only changed the leaking input shaft sealing.

The procedure TIS describes is to remove exhaust and propshaft,FYI....

When I changed on my car the sealing,I removed the diff...,cleaned it from dirt and rust,gave it all new sealings and a fresh paint job...
 

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Gotcha. When you said disconnect the drive shafts, I read that to mean that that step applied to both methods.

Any gotchas with removing/reinstalling the diff?
 

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Discussion Starter · #13 ·
Pretty easy and straight forward to remove the diff,as soon as the part of the exhaust underneath it is gone.takes then about 30min to remove it.
No problem to remove/install it alone with a good floor jack.
 

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Question: If you are disconnecting both the input and output shafts, why not remove the whole differential and fix it on the bench?
One really good reason would be that it weighs 110 lbs.! I'm installing my 3.45 Dinan diff tomorrow and picking that thing up is no fun.
 

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Thank you for your write up and pics. Have you replaced the busings that hold the diff in place? They are number 6 and 9 in the below realoem pic. If so, how difficult was it to do? I have replaced the 3 diff seals and I still have a leak going on and after the last inspection I noticed that the #6 bushing is very worn. That may be contributing to more flex under acceleration and casusing the seals to leak. Your input would be greatly appreciated.
 

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Discussion Starter · #16 · (Edited)
Yep,on mine I changed the bushings.

It is a pain to change them!

Officially you need special tools,but if you can weld and have some steel around,no problem to build the special tools yourself!A gas torch or similar also helps to heat the frame a bit up to get the old ones out.
New bushings in the freezer and heat the frame a bit up and you get them also pretty ok in again.

Will not get today anymore in the garage,but take some pics of my tools tomorrow and post them with some sizes and a fast how to build up.
 

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Discussion Starter · #20 ·
Guys, shave on me!

forgot the camera and am away now from home until sunday!

Have to take pics of the tool(not me,the other tool:hihi: ) then!
 
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