Mercedes 722.9 4Matic Transfer Case Rebuild - 2011 GLK 350 - done in-car, new output shaft cluster

A comprehensive, step by step video showing what you need to know to rebuild your 722.9 4Matic transfer case in the car.

PLEASE NOTE: I strongly suggest also watching the follow-up to this video, where I explain how to set the preload on the bearings, and how to avoid damaging the fragile (!) front output shaft seal.    • Mercedes 722.9 4Matic Transfer Case R...   Between these two videos, you should have the information you need to rebuild your transfer case on a 722.9 transmission.

The newly-acquired 2011 GLK 350 I bought had not only broken the front driveshaft, there was play in the transfer case's output shaft. I broke the case down, not only replacing the output shaft "gear cluster" with a new one (from a vendor in Poland) but replacing the bearings, so this case should last for another 150,000 miles.

I show you the tools, parts and fluids you need to do the job so you can have them all ready when it's time to put the car up on jackstands (or if you're lucky, a lift). I did this job in my home garage using only the same kind of tools you're going to have (or can pick up for not too much money).

Mercedes doesn't sell you the output shaft assembly, so (after doing a LOT of research), I sourced mine from Maktrans, part number SQGX7229.

I also picked up kit for the bearings and seals, part number W7X700/K7X1000 (four bearings/races and two seals).

The long one-use, torque-to-yield bolt that holds on the rear output mechanism is known as a "Hexalobular Bolt" The MB part number is 000000-008248. It's available through MB parts or Pelican Parts:
https://www.pelicanparts.com/More_Inf....

You'll need some automatic transmission fluid (I used Pentosin 134FE). I only needed a quart or so, but I'd recommend having at least 2-3 quarts / liters on hand just in case.

Get some Permatex Automatic Transmission RTV Gasket Maker for resealing the case.

You'll also need a new rear output shaft / yoke nut, Mercedes Transmission Output Shaft Flange Nut, part number MER-1409901150

If you don't already have one, pick up a Mercedes Transmission Fill Adapter, part number CTA-7415

You'll need a race driver that's 3.5" (the cheap kits you can find online normally stop at about 81mm / 3.18"). I went with the Icon brand set from Harbor Freight, their part number 58262.

The bright green chisels and punches / drifts were a new set from Harbor Freight as well, part number 66440 (my old ones are getting tired). ;-)

The hooked pry tool that I used to take out the one bearing race was part of a three-piece set from Harbor Freight, part number 68339.

And of course, you're going to need plenty of generic hand tools, including Torx and allen head bits, E-Torx sockets (E10-E12, as I recall), torque wrenches (ranges from under 10 foot/pounds to over 150 foot/pounds - you'll need at least a couple to cover that range).

Also have a fluid pump on hand, to push the fluid up into your transmission through the drain plug / adapter. I used the (you guessed it) Harbor Freight Multi-Use Transfer Pump, various part numbers, but only a few bucks.

Just be VERY careful when inserting the front drive gear cluster into the (hopefully new) seal. I've learned (the hard way) that the seal is very easy to bugger up. I plan to show a better (safer) installation method in my updated video (dropping the front right-side exhaust to allow easy removal / install of the front driveshaft and inspection of the seal).

I just added a "video" showing the torque values for the bolts associated with the transfer case (this is for my specific car, so I'd recommend double-checking to make sure yours are the same).    • Torque values for the X204 transfer c...  

I might have missed a couple details, but watching the video will show you pretty much what you're going to need to know to do this job (or to decide to NOT do it). ;-)

Good luck with your repair!

And please - if this video helps you, PLEASE like the video and subscribe so I can continue to make similar videos to help out the DIY automotive wrench-twisters.