It's been a while since I last posted. A couple of weeks ago I replaced a leaking airbag on the right rear. While I was raising the car to take the wheel off and get the job done, the shock on the same corner leaked. I thought it was really odd that it happened then, but that's another story.

I ordered and now have two Arnott rear shocks in hand. I'm debating if I should just replace the one which leaked, or both at the same time. I'm sure the other side will give as well at some point which is why I opted to just order the second rather than do it later and wait for it to arrive.

The other side is MB. I'm concerned that if I left them mismatched, they will not be the same with one old and the other new, and will affect tire wear and ride quality.

Another point I wanted to bring up was that I read (i think on the W164 forum) the new Arnott rear shocks are not ADS enabled, even though they come with the ADS designation and wiring. The remanufactured ones are ADS enabled. The wiring on the new shocks is there to eliminate dash light complaints.

I ordered the new rear shocks. My car has ADS.

Edit: found the thread. Post #50. Relates to fronts, not rears.

https://mbworld.org/forums/gl-class-x164/692528-gl-450-front-suspension-mystery-2.html#post7754675

So I wonder what " they will not work with ADS contols" means and if it also affects the rears.

 

Yeah usually do both unless one failed way way prematurely.
Arnott replicates full ADS functionality.
Cheap chinese does not, but just defeats the error message with resistors.

 

Sorry max_blast, I edited my original post before seeing your reply.

I'm not sure when they were last replaced, or if ever. Car is 2010 w/ 150000 km. I've had it for 8 months. Only way to find out is to call the dealer where it was serviced and hope they give me info, which they are not obligated to as I was not the owner then.

Seems like both it will be.

 

Always replace both sides at the same time.

 

It’s longtime Mercedes tradition to replace shocks singly—especially the hydraulic load levelers used in the 1980s-90s before the advent of Airmatic. I did this on my GL but it wasn’t long before the other one leaked too. IMHO 80K miles represents the time to proactively replace the entire suspension, front struts, and rear shocks and springs. This can very likely save your compressor. 80K miles is a good life for a hydraulic shock.

 

Interesting to hear about the long standing tradition of replacing one side only.

I sort of expect that the other side will go as well at some point. I did half the job yesterday, replacing the bad one and it looks like it was not replaced before, judging by the condition of the foam encasing the wheel well. It was intact, no cuts and didn't look like it had been removed before. It's also possible that whoever did the job did it so well that they did not leave a trace of ever being in there.

if these were the original, I am impressed that the shock lasted 10 years and so many kms/miles.

The other side will be replaced within a few days, I don't feel like a job to be done when the weather is cold and everything is so much more brittle.

 

If they are bad due to age, do both.,
If one is damaged, you can get away with one.

They don't wear out and get soft near as bad as old shocks.

 

Good practice is to replace brake components, springs and shocks as an axle set, ie left and right at the same time. This is what I would do.

 

Pads, rotors, steel springs, and front shocks, yes.

Shocks in the rear not as important. I replaced one at about 135K miles due to damage, and the ride was just fine (till the other one started leaking at 170K)
Replaced the second, and the ride is back to normal.