[relative4]

'08 335xi E90 manual stage 1+, 77K miles. A leaky injector on cylinder 2 blew out both bank 1 cats and diluted the oil, seizing the turbos I installed only a year and 5K miles ago. Given that the drained oil reeks of fuel, and given the possible mild bottom end noises I heard during final testing, I've decided to replace the big end connecting rod bearings. The subframe is off, and the steering rack is strapped to the axles. Can I lower the pan/diff/axle assembly enough to access the bearings, or do I need to pull it all?

[Foghorn]

I don’t know the answer to your question, but the pan will need to be lowered enough to clear the oil pump which you’ll need to remove along with oil pick up tube and windage tray to access the connecting rods.

I’ve done N54 rod bearings on an engine stand, challenging enough to replace, clean and correctly seat the bearings. If you use BMW rod bolts the final torque is an angle value, you’ll need room for that too.

[nyt]

You'll need to pull it all out to get access. I don't think you'll be able to reach #1 with the oil pump in there either.

support the rack with something, pull the axles, pull off the front driveshaft, pull off the front diff, and maybe the axle output on the other side if it's blocking any pan bolts.

The pan needs to drop down at least 5 inches or so to clear the oil pickup and pump, then you still need to get in there and reach all the bolts.

Some pics I juts took so you can see what you're working with. I don't think I'd do this job with the engine in the car. If you're doing this work already, you might consider some internal upgrades to go along with those bearings like rods and pistons.

[GearHead335i]

Originally Posted by relative4

'08 335xi E90 manual stage 1+, 77K miles. A leaky injector on cylinder 2 blew out both bank 1 cats and diluted the oil, seizing the turbos I installed only a year and 5K miles ago. Given that the drained oil reeks of fuel, and given the possible mild bottom end noises I heard during final testing, I've decided to replace the big end connecting rod bearings. The subframe is off, and the steering rack is strapped to the axles. Can I lower the pan/diff/axle assembly enough to access the bearings, or do I need to pull it all?

The biggest pain is supporting the engine and dropping the subframe, if that’s already done there would be no reason to not just pull the diff/axles and drop the pan. Sure you might be able to get to them with lowering the pan several inches but again if you’re going to do that just take it all the way down, will make life much easier. I was going to attempt my oil pan gasket without removing everything fully but layer decided against it and I’m glad I did.

[relative4]

Thanks yeah, I've decided to disconnect the axles and front driveshaft and remove the pan and diff.
Next question - since the subframe is off and I have a bunch of swing in the knuckles, can I just pop the inner CV joints out of the diff and the axle support, or do I need to remove the axles from the knuckles as well?

[billowusu]

Originally Posted by relative4

Thanks yeah, I've decided to disconnect the axles and front driveshaft and remove the pan and diff.
Next question - since the subframe is off and I have a bunch of swing in the knuckles, can I just pop the inner CV joints out of the diff and the axle support, or do I need to remove the axles from the knuckles as well?

You can remove the axle from the diff but, you risk damaging the axle. My brother was able to do this on his 328xi. Both 328xi and 335xi share the same components underneath. I compared them both. This video may help as well. I pray this goes well for you!

[relative4]

When you say your brother was able to do this, what exactly do you mean by "this"?
Do you mean he disconnected the inner CV joints and left the outer CV joints connected?

[GearHead335i]

Originally Posted by relative4

Thanks yeah, I've decided to disconnect the axles and front driveshaft and remove the pan and diff.
Next question - since the subframe is off and I have a bunch of swing in the knuckles, can I just pop the inner CV joints out of the diff and the axle support, or do I need to remove the axles from the knuckles as well?

You can do it but again it’s much easier to pop it out of the knuckle first bc trying to pop the inner out of the diff while having the ends still in the knuckle put the geometry of the axle and strut in a weird spot.

[relative4]

Thanks. Last question, I hope. At reassembly time, how difficult is it to pull the axle into the hub? Do I need the special BMW tool for that, or will a bit of oil on the splines allow me to shove it in deep enough to get the nut on the axle?

[GearHead335i]

Originally Posted by relative4

Thanks. Last question, I hope. At reassembly time, how difficult is it to pull the axle into the hub? Do I need the special BMW tool for that, or will a bit of oil on the splines allow me to shove it in deep enough to get the nut on the axle?

Sorry for the delayed response, November has been a busy month. So for the axles you really have two options;

1.) you need to remove both of them from the differential regardless of your method. With that said for the passenger side you’ll have to remove it from the spindle first to get the axle shaft out of the diff and axle support on that side as it is almost 2 feet longer than the drivers side. For the drivers side since it’s much shorter you can get away with leaving the spindle (knuckle) side attached and just swing it out.

2.) you can leave them both connected to the knuckles and take the passenger side apart apart at the inner boot. Just remove the larger clamp and the tri pod bearing will come out. It’s much messier and you’ll have to refill the passenger side with cv grease (it’s a special type of grease, cannot just use regular synthetic grease) but you can keep both of them now attached at the knuckle.

I’d go with option number 2, although you have to refill the passenger side with grease it’s much easier in my opinion than trying to slide the outer cv splines into the knuckle. Ive never used a special tool I just get the Spline to show through the knuckle enough to thread the nut once and then just use an impact gun to get them the rest of the way.

[relative4]

Thanks. With the right $25 tool (Autozone loaner, but I decided to keep it), removing the axles from the hubs was so easy it wasn't worth worrying about. I bought a Bavarian Autosport B8800102 to reinstall them.