Leak in the rear differential of the BMW F32

[heralder]

Greetings,

I recently completed my MOT and received an advise indicating a minor leak from the rear differential seals.


Is anyone aware of the root of this issue and its severity?

The vehicle is a BMW F32 4 Series diesel with a 2.0-liter engine. Thank you.

[torque2me]

There are three seals: one for the input from the propshaft and two for the left and right drive shafts. You will need to inspect to determine which one is leaking.

[torque2me]

The urgency of the repair is contingent upon the extent of the leakage; if the staining is minimal, it may be addressed at a later time, but if the stained area is substantial, it is advisable to undertake the repair promptly.

The movement of the drive shafts is the reason they have a finite lifespan.

[heralder]

I suspect the input seal from the propshaft is the issue. Are you aware of the simplicity of this repair and the estimated expense involved?

[torque2me]

The task should be very straightforward, provided the axle carrier does not obstruct the removal of the exhaust and propshaft. However, I am uncertain about the costs, as they can vary significantly; it is advisable to obtain multiple quotes.

[NevoBMW320i]

I am unaware of your vehicle, but mine was subpar; there is a substantial nut.The BMW F82 M4 differential employs a substantial, single-use M39 nut with a 1.5mm thread pitch for the input flange (pinion shaft), necessitating specialised equipment and considerable power for removal and accurate torque application. Nuts are also related with the axle shaft seals (output seals). I indicated that the Loctite used was not factory-sourced; however, it must have been, as the vehicle had only 20,000 miles at the time of purchase. Regardless, they successfully removed it, but my differential emitted a whine upon reassembly. Consequently, they procured a new differential and installed it, resolving the issue. Naturally, I incurred no costs for the new differential or associated labour. Nevertheless, I remain uncertain about the differences between the M4 and standard vehicles, as the differential fins and similar components are larger and more robust. The initial leak was addressed, and servicing is required following the leak repair.I required a pinion seal from a BMW shop. The service cost was £88, while the repair for the leak was approximately £400. My vehicle exhibited discolouration followed by a weep, prompting me to cease driving until I could schedule an appointment.

[SD1too]

The configuration is consistent across most BMW models currently, making the task exceedingly difficult because to the large shaft and the multipoint pinion nut.

I received a quotation for £350. I believe it pertained to my previous F11 few years ago.