On the Bmw E4 after a lot of miles, seals tends to wear and
Drops of fluid on your garage floor.
Oil around the drive shaft.
If you still have a leak after changing the seal, you have
to change the output flange.
30mm deep thin wall socket
New self locking nuts for output flange/flex and final
Output shaft seal
1. Remove exhaust system: remove the entire exhaust system
as a unit. There is no need to take it apart in sections.
First, remove nuts that hold the exhaust pipes to the manifold
(it may be a good idea to spray with a penetrating oil a few
minutes before you start.) Place a floor jack under the catalytic
converter for support. Remove mounting nut a third the way
down the exhaust assembly. Remove the two rubber hangers from
the center support near the catalytic converter (may need
to loosen the brackets on the underside of the car via a nut.)
Consider replacing these rubber hangers during re-assembly.
Remove rear hangers near the rear left fender (one on either
side of the muffler). Slide assembly toward rear of car and
have a helper guide the front of the exhaust system to the
2. Remove heatshield by removing bolts that hold it onto the
underside of the car.
3. Remove driveshaft: remove lock nuts from flex-disc as well
as bolts. Remove locking nuts from final drive flange. Remove
center bearing support. Move center bearing support to one
side so that front of driveshaft comes off of output flange
centering pilot. Remove driveshaft. Consider replacing u-joints
and/or center bearing at this time.
4. Remove old seal: remove output flange by loosening large
nut (30mm) with a deep, thin-wall socket. One might make on
of these by grinding down the sides of a regular deep socket.
Using a gear puller, remove the flange from the shaft. Remove
seal by prying it out with a screwdriver.
5. Install new seal: lube outer side of seal with automatic
transmission fluid. Use a large socket or short piece of PVC
pipe with end cap attached to drive the seal into the end
of the transmission. Be careful to put equal pressure on all
sides of the seal so that it does not go in crooked. If the
seal goes in wrong, get another one, don't try to reuse it
if it appears damaged in any way. Coat splines of flange and
threads of output shaft with thread sealer and reinstall flange.
Install nut and tighten to specified torque.
6. Install driveshaft using new lock nuts (in reverse order)
and tighten all to specified torque.
7. Install heatshield.
8. Install exhaust system in reverse order taking care to
tighten nuts sufficiently to prevent any leaks from manifold.