[DLucian]

Hi everyone. I am completely stuck with my E91 DIY job. (Rented a lift in a shop)

I did my wheel bearings and now I am attempting to install my rear output shafts. The BMW manual did not mention any special tools, people online seem to simply push them into place.

My right one was stuck long before I could put the nut on the end. Used a hammer to tap it into place (in my book, I only did slightly gentle taps) and when I reached the nut, MY BRAND NEW BEARING NOW HAS PLAY. So, that is now trash and I will have to redo the job and get a new bearing.

On the left hand side, I tried for an hour without a hammer. I just tried to muscle it into place, not a single chance. Started using a rubber mallet, it maybe moved slightly more but still quite a few millimetres before I can put the nut.

How is this stupid thing supposed to work? I feel like setting fire to the whole car

[Tambohamilton]

Have you torqued the nut?

[DLucian]

To add a little more clarification, I am talking about inserting the output shaft in the wheel hub. I greased it (with BMW branded montage grease, for that matter).

I am not sure what nut you are talking about. The nut that goes on the end of the output shaft does not reach the output shaft because it does not go all the way in to the splines of the hub without using a hammer (that just broke my new bearing).

[Brian86]

The bearing isn't damaged. You just knocked one of the inner races a little loose in the axial direction by tapping the half shaft against the hub.

Getting the half shaft in there and tightening everything down to spec will get the entire assembly back home.

Are you using an old hub? Usually the aftermarket hubs/half shafts have much more forgiving tolerances than the stuff from the factory.

Special tools are available for this. I've never needed one. New/Aftermrket parts always went together pretty easily. If reusing old parts I'd always wire-wheel the bejesus out of the stub end and hub splines. Then use some sort of anti-seize/lubricant on the splines.

[DLucian]

I am using the original hub since I didn't see anything damaged. The output shaft originally came out rather decent I would say. Cleaned a little and greased it with BMW branded installation oil.

Did this cause any damage that can lead to premature wear? I'd rather redo the job now in a proper way than coming back to this again.

Was now considering using a shop press to put the shaft in the hub and installing the entire assembly on the car as one piece.

[Brian86]

A press is the easy way to get the bearing and hub into and out of the spindle. It doesn't really help getting the half-shaft into the hub. Removing the spindle is a lot of work itself.

You need one of these things:

That will pull the axle into the hub, and push the two inner races back together.


It's unlikely anything is damaged. All the bearings use a plastic bearing cage. Depending on the bearing manufacturer, some of them incorporate a bearing cage with plastic pawls that 'snap' into the inner races and those pawls may have been bent or broken.

Up to you if you want to take it apart and start fresh... I can't make much of a diagnosis from the other side of the world. I'm just speaking from experience disassembling BMW bearings on the bench and this is more-or-less how they come apart.

[Tambohamilton]

Hammer it in there and torque the big nut. Then see what's what. It's a 4 point contact bearing, so it'll behave as if it has some play until the output shaft is installed and the big nut torqued properly. It's unlikely the bearing is damaged at all.

[DLucian]

Okay, so, big thanks to you guys for helping me out. I can confirm you were correct. After torque-ing everything down, there was no more play. Car made around 3000 km since than and it's all good.

Also, if this helps other noobs like me, for the other side I ended up using a drill on the impact setting only and pressed into the side of the hub. It took just about 2-3 seconds and it was in well enough to grab it with the big nut.

Thanks again for all your help.

[Andystobbs]

90% of fixing older cars is cheats and work arounds