LWA500

[PR1AWRet]

Some highlights for the LWA500 transfer case in a (11/01 build date) 2002 BMW X5 E53 Sport.


There are a lot of posts on the different forums and Youtube for the removal of the transfer case. It is the same for both NV125 and LWA500. As with the transfer case, you will have to pull the stiffener plate, exhaust, heat shielding, and drive shafts.


Now would be a good time to inspect the front and rear Giubo (Jew-boh)/flex discs. I prefer OEM for these.


Inspect the front drive shaft for spline engagement in the transfer case and for corrosion.


Up on the table ready for chain replacement. I drained the oil while it was in still attached to the transmission. Break all of the star bolts around the case. I used the drill, a 3/8 adapter, and an E-12 star socket. (A 12 point 10 mm socket/wrench works too.) to remove them all after they were broken loose. When you are ready to split the case apart, there are 4 tabs. Take a dead blow hammer or block of wood and hammer and start on a tab and work your way around. Yea, that didn't work so well. When I got a gap, I used a couple of screwdrivers and would stick the tip in, but not to pry, to use as a wedge. Mine made a pop after about ¼ inch gap. When the case is open you should get a better understand why.




If you notice you DO NOT have to take the flange off to separate the 2 halves or the BIG nut on the inside. Take some 1200 grit sand paper to clean the centering pin. I put wheel bearing grease on it when I put the drive shafts back on. The planetary gears to the right came out the same time when I split the case. (The NV125 planetary gears doesn't have the shaft like the LWA500 has)



Check the round spot, if it has a tag, usually it will be a NV125, if it doesn't, scrape the gunk off and look for LWX 122 or just look to the right in the webbing for the LWX 122, this signifies this is a LWA500.(some ones reasoning.) Make sure to put the magnet back in its spot on the inside of the other half of the case. It's that round black thing close to the bottom of the picture.




This is the other side of the case. The LWA500 uses ball bearings instead of roller bearings for the NV125. In my opinion the LWA500 is a stouter case. This is the old chain.




Side view of the planetary gears left and sun gear to the right. The larger end of the planetary gears slides into the sun gear so as to have the smaller end protruding out.





A better picture of the planetary gears on the sun gear. (This is the only rebuild picture.) Just look at the other pictures to figure out. Should be easy. This has the new chain on it and ready for the other half to go on. The chain has no specific way to go on the gears. It was a pain to get the gears and chain in that special spot for them so slide back in. A helper would have made this easier. Put the planetary gear on after you have the gears and chain in place. The LWA500 and the NV125 use the same chain with one (1) blue link. Use a thin layer of RTV Black (My favorite for anything) around the mating area. Make sure the magnet is installed down by the location pin in the space provided. When putting the other half on make sure not to mess up the seals. The bearing on the top in this picture needs to fit squarely in the other case. I used 4 of the bolts and tightened each one about 1 turn at a time to bring it down squarely. Make sure your planetary gears are meshed with the sun gear and ring gear.




On the LWA500 the roller bearings are in a steel cage vise plastic on the NV125. There are no waffle rings to worry about putting back in there either.



I used my block of wood and hammer and rapped the front output a couple of times. This will unseat the bearing/shaft on the other side. The dust cover will come off also.



On a NV125 where my finger is pointing, there is a lock ring that needs snap ring pliers to release the bottom bearing. There isn't one for the LWA500. This is where I realized I had a LWA500. You can see the bottom ball bearing is sliding out of the case already from where rapped it on the other side of this case. It pulls out from there.





And all the way out. At 188,00 the bearings are real smooth.




And the other end coming out. Takes some pulling to get out.




This is my first BMW case I've been in and this is how the parts came out. The bearings are not a press to fit, like the bottom gear with the 2 ball bearings, I could use my hands to take them off. That's a tight fit to me.





The date of mfg for this case is 12-09-01, the build date for my BMW 11/01.





When you are ready to install the transfer case, have the transmission angled down a bit. It will give you more wiggle room. This is really a 2 person job that requires aligning the splines from the transmission output shaft to the transfer case and (if done) aligning the extended spline front drive shaft. This is the only time that the extended spline drive shaft can go in. If you are the only one putting this in, get the transfer case up there and install 3-4 bolts about 3 turns in and then figure out a way to align the extended spline front drive shaft while sliding the transfer case on and aligning the transmission output shaft. I called my Son to help. See the rear O2 sensor wire hanging there, yea, make sure it's out of the way. I got lucky.

[tempest411]

LWX500...

[PR1AWRet]

LWX?
I gave it to my son in 2019. Now I have a 2018 50i fully loaded since 2020.