Recently purchased a 2013 GLK 350 with about 86K miles. The 4matic front transfer shaft u-joint failed.
What's the average lifespan of this component?

 

Do you mean the one in the transfer case? #6 in the picture? bathed in transmission fluid it should last forever, unless a) it was defective or b) a lot of damage was done to the front end by rock crawling or other.

 

The u-joint on our GLK failed at the front differential.

 

This is an open universal joint. This type of joint has been used in cars since the early days and should give long life on at least a couple of 100 thousand miles. There is always a chance that you got one with bad needle bearing.


It is possible to damage it by hitting a rock or running over something but you can see that the UV joint is above the bottom of the oil pan.
Looks like the bearing cups are staked in and need special tooling to replace. Shafts are available on e-bay if you don't want to pay full price for a new one.

 

Thanks for the diagram. Under normal highway driving - and regular MB inspections, wouldn't the failure of that front u-joint start showing signs prior? It would seem that it would have been caught prior to completely coming apart.

 

yes, it will start making noises and as long as the technician is observant enough while doing regular maintenance or routine inspections, they will see the issue.

I have seen a few dozen of these driveshafts fail at the connection to the front differential. Usually it is too late and ended with catastrophic failure and damages. When that front joint is wearing out, you may feel some clunking in the front of the car on acceleration from a stop or you will hear a squeaking noise that varies with vehicle speeds. If you are under the car and yours is worn/wearing out, you will start to see what I call Rust Dust around the front driveshaft bearings.

Obviously it is a lot cheaper to replace the driveshaft before it fails, instead of totaling out your car with oil pan, transmission, and subframe damages that can also occur on severe cases.

 

My 2010 GLK350 - 160,000 miles has the brown dust/wear signs you describe....

Now as for costs of replacement - my mechanic is quoting $1300 USD - reasonable? I plan on keeping this vehicle for a while....

Chuck

 

2015 GLK350 2WD 99,000 miles. I do most routine maintenance and checks in my moderately well equipped garage. I follow MB recommended schedules. 229.5 recommended oil and OEM filter are changed at 10,000 miles or less. Changed transmission fluid and filter at 60,000+ miles, etc. The only thing that I have neglected is the spark plug replacement at 46,500 miles. All my other MBs went past 100,000 miles on platinum or iridium plugs. It's not a recommendation, just what I have not yet done.

The first component failure ever in the car was a crankcase vent valve at 96,000 miles. It caused a screeching noise that at first sounded like a bad belt or failed pulley. Indy mechanic friend diagnosed the problem in 5 minutes and had the car back to me the next day.

The car recently had an isolated incident where it did not shift out of PARK for my wife. She shut down the engine and restarted the car and everything seems OK.

We are very pleased with this car.

 

Our 2005 ML350 4 Matic had a drive shaft bearing fail at 160,000 miles, so maybe that is the lifetime of those components. The quote was lower but that was 5 years ago, also.