This is a great thread! I've got a 2003 X5 e53 3.0, with 150,000 miles that made a ratchet clacking sound under hard acceleration, but it was quiet on slow starts, so basically exactly what everyone on this thread said theirs did.

Here are some tips I wished I knew before doing this transfer case chain job, kinda following my nose and most of the instructions from everyone else. Passing 'em forward:

1. I rolled the front wheels up on 7"-8" high car ramps and leveled the rear end, wheels off the ground, on jack stands. That was enough, with trans in neutral and e-brake off it was easy to spin rear wheels for spline/flange alignment.

2. I removed the TC completely, which clearly made it easier to work on and clean internally than it would be if you left the back half attached to the transmission and did it all lying on your back. Yes this job can be done without completely removing the TC because the two gears for the chain slide out. The circlip that holds the front drive shaft gear on was a b#tch, so I left that one it place, put the new chain for a NV125 New Process TC (from Cobra Transmission parts, check your TC model number, on badge, easy to see) over both gears and gently tapped the main shaft gear in place, no problem.

You DEFINITELY need a star ratchet wrench, e10-e12 mm combo (see pic, mine was a Powerbuilt brand, eBay, $9.00 worked very nice) and separating the TC from the trans is no prob.

3. You DO NOT need to unbolt the drive shaft ends, front or rear, at the far differential pumpkin ends!! Just remove the 6 rear drive shaft bolts (and the rubber damper disc) right close to the TC. Knowing this woulda saved me a bunch of time and hastle.

On the REAR drive shaft, just remove the center support and have someone pull shaft (with hands) away from the TC and it'll just slide off it's center pin. The front drive shaft is splined so it slides right out of TC when you separate it from the tranny.

4. You DO NOT need to remove the exhaust, just unbolt and tweak the alum heat shield to get to the crossmember bolts. BE CAREFUL! Twice I dropped the cross member bolt or socket INTO the hollow cross member , necessitating removing the crossmember to tip it out. Of COURSE I was always on the LAST bolt both times it happened...

5. You DO NOT need to remove the large 36 mm nut that secures the drive shaft flange to the TC output shaft (unless you're replacing seals, bearings behind it). Leave it alone.

6. I used AC Delco Engine Sealant 88864346 to seal the TC case gasket-less halves. It behaves much differently than silicone, tougher, more firm, bonds to metal surface way better. Use it for EVERYTHING that needs sealing.

Since my seals weren't leaking I left them and the bearings alone. Don't forget to put a little bead of grease between the lips of the rubber seal before sliding it back on the trans output shaft.

The job overall was not too difficult, straightforward, and a tremendous savings ($100 DIY vs $2,000+ at the dealer). Thanks XPosters, you saved me again !

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