vantaam5

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...

__________________
2003 M5 "The Matte Black Money Pit"

ALPHA-N by EVOLVE,Power remapped-modified heads-Schrick cams-modified throttle bodies and velocity stacks-modified rods and crank-EVOLVE headers
-Willans 4-point harness -CAI with custom built MAF delete tubes fed through fog light covers -lighter oem flywheel-Sachs performance clutch-clutch stop-Drexler differential stock ratio-electric fan with control unit-545i SSK-HEL braided teflon brake lines-IATS reloction-Bilstein PSS9-HD sway bar links-M3 swaybar brackets rear-CF bonnet with vents-subframe reinforcement-40mm wider fenders front and 25mm rear-aluminium ///M pedals and foot rest-CF roundels-LED AE-foglight delete-AP BBK kit 6piston calipers front-CF strut bar front-full suspension rebuild-camber plates with uniballs front-Dinan sway bar-illuminated inner door handles-Alcantara roof liner-M-Audio system- Hamann HM2 10x19" wheels 275/30 front and 295/30 rear



2002 M5 former known as "The Breaker"
Carbon black/black sport interior/titanium trim,37k miles,bone stock
-20cm of the trunk and quarter panels missing...
-rebuild in winter 2011/2012

2001 530iA Touring/Orient blue/tan leather
-"submarine edition",a bit boost and some M5 parts...


1979 635CSI Black/white leather
-dog-leg-LSD-restoration project

ger

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.

__________________
11/2000 M5 Le Mans Blue

My car's thread

ger

Sorry, double post.

StreetDragster

Cheers for this thread, and yep i'm interested in a rebuild one

Thanks

Matt

Neil.D

Excellent thanks brother!

__________________
2000 M5 Titanium silver

ger

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.

frank///M5

do you put the car on a lift?

i need to do it on my beast,but is it easy to get the exhaust of when the car is not on a lift?

vantaam5

I do not have a lift,so I get it up as much as possible on jack stands..

frank///M5

thanks,i go for it after the summer.

i will take the beer today.

mooch

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