[Bozz80]

While replacing a bunch of parts in the front end suspension of my 2008 335xi, I noticed the shaft seals in the differential weren't great so I replaced those, but without replacing the circlips on the axle shafts. The suspension sounded great for a little while and then started rattling again.

I pulled off the skid plate and when I push and pull on the CV joints, I can rattle them against the differential, making the same noise I hear when driving. I'm going to replace the circlips to see if that fixes it but please let me know if I should look for something else.

The real question is with the driver's side axle. I can move the axle shaft that is between the two joints back and forth (push towards and away from the CV joint). It makes sense that there is lateral play in the CV joint but I'm worried that the bearings in the wheel joint are now going. Am I going to have to replace the bearings or axle because of this?

[bmwbob89]

The circlips just hold them into the diff. Not really a wear item. If they are locked into the diff they are fine.

[e90yyc]

Any issues with a bit of movement? I too have this.

[Bozz80]

Originally Posted by bmwbob89

The circlips just hold them into the diff. Not really a wear item. If they are locked into the diff they are fine.

The axle shafts are locked in. They don't appear to have come out while driving and I can't pull them out just by hand. And it really isn't a problem. Doesn't affect the feel during driving.

The problem is that they rattle a lot. Sounds like the car is going to fall apart. I'd like to secure the axle in the joint so that it stops rattling.

[E92_William]

There is supposed to be a bit of play in and out when pulling on the shaft between the two joints but nothing more than I'd say half an inch probably less, judging by my rears and one good front one. I don't see any reason it would rattle unless it came out of the spline or it's seriously fucked

[e90yyc]

Originally Posted by Bozz80

The axle shafts are locked in. They don't appear to have come out while driving and I can't pull them out just by hand. And it really isn't a problem. Doesn't affect the feel during driving.

The problem is that they rattle a lot. Sounds like the car is going to fall apart. I'd like to secure the axle in the joint so that it stops rattling.

You sure it’s the axle shaft that’s rattling though?

Originally Posted by E92_William

There is supposed to be a bit of play in and out when pulling on the shaft between the two joints but nothing more than I'd say half an inch probably less, judging by my rears and one good front one. I don't see any reason it would rattle unless it came out of the spline or it's seriously fucked

Good to meet you!

[E92_William]

Originally Posted by e90yyc

You sure it's the axle shaft that's rattling though?

Good to meet you!

Totally new here lol

[Bozz80]

Just found these pics of the old circlips. You can see the warn parts are more shiny than the rest of them.

Do these look warn out enough to be allowing that play in the spline gear?

I'm going to replace these (hopefully) tomorrow.

[PhaseP]

Some axial play is normal. Radial play is not. The circlips do not wear out, but they get flattened out, making them easier to pop out from differential. That's why it's good to replace them. Oem diff seals come with new new circlips and if you compare them to old ones you will see new ones are less round and stick out more when installed on the axle groove.
Your noise may come from something else.

[Bozz80]

Originally Posted by PhaseP

Some axial play is normal. Radial play is not. The circlips do not wear out, but they get flattened out, making them easier to pop out from differential. That's why it's good to replace them. Oem diff seals come with new new circlips and if you compare them to old ones you will see new ones are less round and stick out more when installed on the axle groove.
Your noise may come from something else.

It looks like you, and a couple of other folks that commented earlier, were right. It wasn't the axles at all. It was the sway bar.

Total noob move. Should have listened to you.

Luckily circlips aren't that expensive so I only wasted a bit of time. I replaced the circlip on one side and immediately realized that this didn't solve the problem. New circlips reduced the play but didn't eliminate it. After that, I started rattling stuff and found that the sway bar screws were loose.

Thanks all.