[D Griff]

Hey all! I have a 2014 328i M Sport 6MT, 47K miles. The car has been quite reliable and well maintained up to this point with a few mods (tune, suspension, wheels/tires) but I've recently run into chassis stabilization/ABS codes while on the highway. I took it to a local shop for an alignment and to scan the codes. They came back with ABS wheel sensor failure. Easy enough, I'll DIY that.

They also found that my car has a significant leak from the transmission output shaft seal and said that I should have them replace it immediately to the tune of $1K (parts are cheap, mostly labor).

I've been digging into this and I can't find any info, history of this happening on any other 6MT cars on the forum, etc. I did find this for the 1 series. https://www.1addicts.com/forums/showthr ... ?t=1815554

I assume it's a similar job, this process is more than I'm willing/have time to tackle at home, and $1K for all that actually seems rather fair. My concern is that the shop is just hosing me and it's a non issue. There is no oil under where I park but presumably it’s all collected on under body cladding? I'm thinking maybe I'll ask them to share some photos with me before pulling the trigger. It does seem like a very random/labor intensive thing to fabricate. They also did say when I brought in the car, the battery could cause issues and they are saying that it's still great (same one since at least 2018 when I bought the car at 15K miles).

I don't get a fleecing vibe from this shop and they are specialists for BMW and have excellent reviews, but I have pretty minimal experience using shops and typically DIY most things.

Any advice from the group?

[X Mon™]

Does it happen, sure. 47k seems pretty premature for an output shaft seal to leak, but it's definitely plausible. A quick jacking of the car and removal of the center belly pan should give you enough access to visibly inspect the transmission. If it's truly leaking as they claim, you'll see/feel fluid down the backside of the transmission itself, and there is likely a witness spray on the transmission tunnel.

The link you have posted is broken, but going to thread 1815554 makes things way more over complicated than need be. In my experience you can hold the output flange by hand and remove the nut GENTLY with an impact gun. Alternatively something along these lines: OTC-4754 typically works for a counter-hold. You will need a thin-wall 12-point deep 30mm socket. The exhaust can likely be sagged enough to get the driveshaft bolts out between the guibo and flange without full removal, and the transmission cross-member can likely stay in place. At worst its an exhaust gasket, the drive shaft bolts (they're one use stretch bolts) and the seal itself.

All that said, for reference I was quoted a little over 1k at the DEALER to change the rear differential pinion seal on my F15 (same setup as the F30s). Same process, other end of the driveshaft. I ended up buying all the tooling [50mm spanner insert, ring wrench, counter hold socket, seal driver] from the dealer parts department and doing the job myself for ~$400. Point being, IF you actually need the work, the price you were quoted is likely inline with dealer costs. If it does need done, it may make sense to at least get a quote at your local dealer.

[sqwinny]

I have no idea about life of these but thanks for giving me another thing to change while I change my clutch + flywheel within the next week.

[im_an_alien]

Originally Posted by sqwinny

I have no idea about life of these but thanks for giving me another thing to change while I change my clutch + flywheel within the next week.

Get the 550 clutch!

[sqwinny]

Originally Posted by im_an_alien

Get the 550 clutch!

It doesn't fit on the n20. Splines are different.

Spec steel single mass flywheel + stage 3+ clutch and pressure plate.