back gate failure
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Junior Member
Joined: Sep 2019
Posts: 29
Likes: 3
Gl450
back gate failure
My 2012 GL450 has a back gate that has gone from bad to worse. It started devoloping a grinding type of noise when opening closing and it got to point when opening it would only go up half way and I would manually push it up rest way. It also start developing issue of having a hard time sitting still after going down, it kept wanting to go back up and I learned to push it tight and hold it for a sec until I could hear the lock engage. Now today, the thing will not close, it doesnt engage the lock at all and so it swings up and down freely while I drive. Can anyone tell me what they believe is issue and parts needed and cost for them? is it hard job?
MBWorld Fanatic!
Joined: Jan 2010
Posts: 3,122
Likes: 785
NGL450 w/EORP, S550
that sounds like a failure of the hydraulic ram.
Make sure you check the hinges that they aren’t obstructed in anyway.
The parts bill is gonna be pretty steep if you’re gonna go buy this at the dealer, so I would just convert it to a manual gate at this point.
Disconnect the hydraulic ram in the top right corner and replace the shocks with manual ones from the ML.
Problem solved. You now have a manual rear gate.
Make sure you check the hinges that they aren’t obstructed in anyway.
The parts bill is gonna be pretty steep if you’re gonna go buy this at the dealer, so I would just convert it to a manual gate at this point.
Disconnect the hydraulic ram in the top right corner and replace the shocks with manual ones from the ML.
Problem solved. You now have a manual rear gate.
Last edited by Max Blast; Mar 6, 2026 at 10:53 PM.
Senior Member
Joined: Aug 2018
Posts: 415
Likes: 122
From: Kelowna, BC
08 GL320 CDI
First off check the fluid level in the reservoir for the hydraulic system. When I first got mine 9 yr ago the liftgate did the same thing. I opened up the spare tire area, opened the pump and checked the level, it was low. Bought a liter of hydraulic fluid, used about a 1/3 of it only and it's been working perfect since.
Took like 45 mins to do.
Last edited by Sallad; Mar 7, 2026 at 02:02 AM.
MBWorld Fanatic!
Joined: Jan 2010
Posts: 3,122
Likes: 785
NGL450 w/EORP, S550
Whoa there buddy, slow down!
First off check the fluid level in the reservoir for the hydraulic system. When I first got mine 9 yr ago the liftgate did the same thing. I opened up the spare tire area, opened the pump and checked the level, it was low. Bought a liter of hydraulic fluid, used about a 1/3 of it only and it's been working perfect since.
Took like 45 mins to do.
First off check the fluid level in the reservoir for the hydraulic system. When I first got mine 9 yr ago the liftgate did the same thing. I opened up the spare tire area, opened the pump and checked the level, it was low. Bought a liter of hydraulic fluid, used about a 1/3 of it only and it's been working perfect since.
Took like 45 mins to do.
