[blown07]

Going to be doing a front differential change and have a couple of question I can't find in Bently manual or on line

1. The bentley manual only references taking out the drivers side axle. Is the intention to remove only drivers side and slide the differential off the passenger axle? I can only imagine both axles have to come out before removing diff

2. I am debating whether to buy the passenger side "support bracket" which is the bearing on the right side of the oil pan. I can't tell if this bearing gets differential oil or if it's a sealed bearing. I will likely replace if it get diff oil as it's likely contaminated. My guess here is it does get diff oil based on the arrangement.

Any help is appreicated.

Thanks

[ucdbiendog]

Let me know how this goes, particularly with #2. I will probably try to re-seal that bearing block when i replace my oil pan gasket. I haven't seen anywhere what it is sealed with (looks like some kind of RTV compound).

[ucdbiendog]

did you ever do this?

[blown07]

Originally Posted by ucdbiendog

did you ever do this?

Will be doing it this week. I can see from the new bracket I have that there is an o ring on the end that goes into the oil pan tube so the diff oil does travel through and feed oil to the bearing in this bracket, The silicone that is on the backet must just be there for backup.

[ucdbiendog]

any pictures you could take would be way appreciated

[blown07]

Originally Posted by ucdbiendog

any pictures you could take would be way appreciated

Attached are a few pics of the front diff change out that I did after Christmas. Install was straight forward. Split it over 2 days as I was recovering from the flu...4 hours one day to get everthing off and 5 hours to get it all together. I removed both sides (axles and hubs together) along with the axle bracket that is bolted to the side of the oil pan. I found that by leaving the sway bar links attached the sub frame will hang from this and give lots of room to get the diff out. The subframe will actually pivot from the front so there is no stress on anything doing it this way. My car is quiet again..ya. The inside of the diff and axle bracket were spotless but I could feel some roughness in the front pinion bearing. It also seemed like the front diff spider gears were binding. I can't actually say where the problem started as the gears looked fine. If I had to guess I would say the preload on the pinion changed somehow. You can see in one of the pics ucdbiendog that there is a seprate plate with the sealant that I didn't need to touch.
pics to follow

[kaw900r]

I am changing mine out cause it cracked. How did you hold the rear so you could loosen 4 torx bolts? t/u

[blown07]

Originally Posted by kaw900r

I am changing mine out cause it cracked. How did you hold the rear so you could loosen 4 torx bolts? t/u

I used an impact wrench, however I would recommend that you do this first before removing the brakes and have someone in the car press and release the brakes as required so you can undo with a hand wrench. You def need to use this method to torque them down to spec as one of the last steps during install. I used new bolts and locktitght for these. I didn't do the torque to yield method for these as it seems kinda crazy to me. I just used around 45ftlbs and marked the bolts to check down the road.

[kaw900r]

T/u I will have my wife press on the brake so I can loosen them.

[kaw900r]

How did you pop it out? Very tight space was trying to get a flat head up in there. Waiting on my wife to press on brake so I can loosen 4 torx bolts. Lower control arm was a bear to get loose from ball joint. t/u

[ucdbiendog]

Originally Posted by blown07

Attached are a few pics of the front diff change out that I did after Christmas. Install was straight forward. Split it over 2 days as I was recovering from the flu...4 hours one day to get everthing off and 5 hours to get it all together. I removed both sides (axles and hubs together) along with the axle bracket that is bolted to the side of the oil pan. I found that by leaving the sway bar links attached the sub frame will hang from this and give lots of room to get the diff out. The subframe will actually pivot from the front so there is no stress on anything doing it this way. My car is quiet again..ya. The inside of the diff and axle bracket were spotless but I could feel some roughness in the front pinion bearing. It also seemed like the front diff spider gears were binding. I can't actually say where the problem started as the gears looked fine. If I had to guess I would say the preload on the pinion changed somehow. You can see in one of the pics ucdbiendog that there is a seprate plate with the sealant that I didn't need to touch.
pics to follow

Thanks man. the axle support bracket that you did take off, it didn't have any fluid in it (differential or motor oil?) did it? The plate that you left in place, any idea what it was sealed with?

[blown07]

Originally Posted by kaw900r

How did you pop it out? Very tight space was trying to get a flat head up in there. Waiting on my wife to press on brake so I can loosen 4 torx bolts. Lower control arm was a bear to get loose from ball joint. t/u

As I recall I removed the four bolts that held on the axle bracket and then used a small pry bar between the axle bracket and the oil pan which made it easy to pop the axle out of the diff. There is even a notch at the bottom of the bracket to get it started.

[blown07]

Originally Posted by ucdbiendog

Thanks man. the axle support bracket that you did take off, it didn't have any fluid in it (differential or motor oil?) did it? The plate that you left in place, any idea what it was sealed with?

The axle bracket is fed with diff oil through the tube that travels through the oil pan. There is an o ring on the axle bracket and on the differential that seal this connection on both sides of the pan. The plate looks like it's sealed with a heavy duty white RTV but I would imagine you could use any good black auto RTV.

[blown07]

btw I just used a hammer on the tie rod end joint and the control arm ball joint and they will come off in 3 or 4 good hits with a jack under the steering knuckle.

[kaw900r]

Did you have to drop sub frame or remove rear shaft to get it out? I have it loose and even a bearing ring dropped out but can't get it out. Before I remove something I don't need to figured you would have the answer. t/u

[blown07]

Originally Posted by kaw900r

Did you have to drop sub frame or remove rear shaft to get it out? I have it loose and even a bearing ring dropped out but can't get it out. Before I remove something I don't need to figured you would have the answer. t/u

I used a single jacksstand under the oil panel as shown in the picture and then removed the four motor mount screws. Then with a jack under the subframe remove the 6 subframe bolts and lower it down until it hangs on the sway bar links. I also had to give the wire going to the ride height sensor extra slack. You will also need to remove the drivers side motor mount completely to get at one of the bolts for the diff. You also need to remove the holder clip on the front of the motor to allow the transmission lines to move slightly to get at the other top bolt. I left the front drive shaft in place with only the front of it disconnected but you have to be careful when you jack the sub frame back up that it doesn't get pinched.

[kaw900r]

T/u I will get back under it tomorrow morning and deal with sub frame. I have it completely loose the side going to passenger axle cracked and noticed in your pic that you removed the housing the pass axle goes thru. Which is good since part of the diff that slides into the housing cracked off also. Will try to use pliers to remove but if not at least it can be removed to make it easier to work on. Your pictures were very helpful as were your answers. Didn't want to hi-jack ur thread but no one is replying to my thread. T/u again will let you know how it goes.

[blown07]

No problem. You should consider a new oring for the diff housing that fits into the oil pan tube if you are getting a salvaged diff and possible an oring for the axle bracket as these are very cheap but a real pig to get at if the old ones leak ie. start over. g/l

[Julian2485]

Originally Posted by blown07

No problem. You should consider a new oring for the diff housing that fits into the oil pan tube if you are getting a salvaged diff and possible an oring for the axle bracket as these are very cheap but a real pig to get at if the old ones leak ie. start over. g/l

What diff oil did you use after the install was finished ?

[blown07]

I used royal purple 75w90...and spilled about a 1/3 of it on the ground lol..had just enough left to fill it..only mistake I made but still annoying

[PhaseP]

BMW oil for differential is SAF-XO Final Drive. This goes into rear differential also, but not if it is an LSD diff. 0.63qt for front diff, 1.05qt for rear.

I had bought from ECS tuning when I had changed mine, price wise not much different than others. The pictures in the link show Castrol bottles, but I received bottle with BMW sticker on it. Probably Castrol is the same one, if you receive a Castrol bottle.

http://www.ecstuning.com/BMW-E90-325...uid/ES2562683/

[PhaseP]

Question for people who have the passenger side support bracket removed or replaced, does it have a real bearing on it that the axle rides on, or is it just supporting the axle by the seal lips that is on the outside entrance of it?