2019 GLS 450 Questions
Thread Starter
Newbie
Joined: May 2025
Posts: 2
Likes: 1
2019 GLS 450 Questions
Hello. New to the MB world but looking at purchasing a loaded 450 with almost 60,000 miles. Anything I should be concerned about with these? I hear the engine is a good one? But is there any common issues with these? I’m in the Midwest where there’s salt and the vehicle spent its whole life in Florida, so that seems good.
Just wondering how long I should expect it to last and what issues that may come up down the road that may be large expenses.
Thanks for your advice
Just wondering how long I should expect it to last and what issues that may come up down the road that may be large expenses.
Thanks for your advice
Out Of Control!!
Joined: Sep 2018
Posts: 14,680
Likes: 4,579
From: unbegrenzt
2017 GLE350 4MATIC
Engine is good. 5k mile oil change intervals, check wiring harness for signs of oil, replace plastic tubes underhood before they break.
Transmission is middling as is normal for MB. Change the oil now.
Air springs are regular maintenance items. 100k miles or thereabouts. Suspension level sensors can go bad.
Second row folding seat mechanism can be problematic, read this site.
Water leaks at A-pillars and liftgate area can wreak havoc on electronics, read this site.
Imo these should be capable of 200k miles if 100% of the maintenance is kept up with, hypervigilantly. However there are no 200k mile reports yet, that I am aware of, on this site.
Transmission is middling as is normal for MB. Change the oil now.
Air springs are regular maintenance items. 100k miles or thereabouts. Suspension level sensors can go bad.
Second row folding seat mechanism can be problematic, read this site.
Water leaks at A-pillars and liftgate area can wreak havoc on electronics, read this site.
Imo these should be capable of 200k miles if 100% of the maintenance is kept up with, hypervigilantly. However there are no 200k mile reports yet, that I am aware of, on this site.
Last edited by chassis; May 21, 2025 at 12:57 PM.
MBWorld God!
Joined: Dec 2019
Posts: 32,406
Likes: 6,337
Engine is good. 5k mile oil change intervals, check wiring harness for signs of oil, replace plastic tubes underhood before they break.
Transmission is middling as is normal for MB. Change the oil now.
Air springs are regular maintenance items. 100k miles or thereabouts. Suspension level sensors can go bad.
Second row folding seat mechanism can be problematic, read this site.
Water leaks at A-pillars and liftgate area can wreak havoc on electronics, read this site.
Imo these should be capable of 200k miles if 100% of the maintenance is kept up with, hypervigilantly. However there are no 200k mile reports yet, that I am aware of, on this site.
Transmission is middling as is normal for MB. Change the oil now.
Air springs are regular maintenance items. 100k miles or thereabouts. Suspension level sensors can go bad.
Second row folding seat mechanism can be problematic, read this site.
Water leaks at A-pillars and liftgate area can wreak havoc on electronics, read this site.
Imo these should be capable of 200k miles if 100% of the maintenance is kept up with, hypervigilantly. However there are no 200k mile reports yet, that I am aware of, on this site.
When buying the used vehicle, get a PPI (Pre-Purchase inspection).
The usual stuff, all mounts, condition of sparkplugs, injectors, camshaft adjusters, brake fluid, power steering fluid (if applicable), coolant, transmission fluid, front diff fluid, rear diff fluid, transfer case (the 3 mentioned, if 4MATIC otherwise just rear diff fluid), driveshaft hangers, engine and transmission mounts, alignment, wheel balancing, tires, brake pads, brake rotors, check condition of coils, oil change (analysis via Blackstone labs?, same goes with all the fluids)?, if equipped, airmatic system condition, 12v battery condition, aux battery condition, check timing chain, all belts and pulleys, check to make sure there is no oil in wiring harness (a common issue on certain MB engines that can get into the ECU, destroying it). I will add if I remember more.
Junior Member
Joined: Aug 2024
Posts: 20
Likes: 1
2019 GLS 450
All this and:
When buying the used vehicle, get a PPI (Pre-Purchase inspection).
The usual stuff, all mounts, condition of sparkplugs, injectors, camshaft adjusters, brake fluid, power steering fluid (if applicable), coolant, transmission fluid, front diff fluid, rear diff fluid, transfer case (the 3 mentioned, if 4MATIC otherwise just rear diff fluid), driveshaft hangers, engine and transmission mounts, alignment, wheel balancing, tires, brake pads, brake rotors, check condition of coils, oil change (analysis via Blackstone labs?, same goes with all the fluids)?, if equipped, airmatic system condition, 12v battery condition, aux battery condition, check timing chain, all belts and pulleys, check to make sure there is no oil in wiring harness (a common issue on certain MB engines that can get into the ECU, destroying it). I will add if I remember more.
When buying the used vehicle, get a PPI (Pre-Purchase inspection).
The usual stuff, all mounts, condition of sparkplugs, injectors, camshaft adjusters, brake fluid, power steering fluid (if applicable), coolant, transmission fluid, front diff fluid, rear diff fluid, transfer case (the 3 mentioned, if 4MATIC otherwise just rear diff fluid), driveshaft hangers, engine and transmission mounts, alignment, wheel balancing, tires, brake pads, brake rotors, check condition of coils, oil change (analysis via Blackstone labs?, same goes with all the fluids)?, if equipped, airmatic system condition, 12v battery condition, aux battery condition, check timing chain, all belts and pulleys, check to make sure there is no oil in wiring harness (a common issue on certain MB engines that can get into the ECU, destroying it). I will add if I remember more.
MBWorld God!
Joined: Dec 2019
Posts: 32,406
Likes: 6,337
I have a question with regards to only doing the rear differential fluid if it’s 4matic and not front differential or transfer case fluids? I am planning on having an independent mechanic do this at the next oil change interval along with the transmission fluid/filter chance. Please help me understand, thank you 🙏
MBWorld God!
Joined: Dec 2019
Posts: 32,406
Likes: 6,337
The front differential is a hard worker, it uses a small amount of fluid, it is a small differential compared to the rear differential, it holds the engine (well, other than the engine mounts of course), it handles the turning and twisting maneuvers. You also especially want to change it sooner if you tow although being a rear wheel drive vehicle, the rear differential works harder when it comes to towing.
Trending Topics
MBWorld Fanatic!
Joined: Jun 2021
Posts: 1,923
Likes: 522
From: New Hampsha
'17 GLS450, '14 GLK250, Grandpa's Roadster
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
Junior Member
Joined: Aug 2024
Posts: 20
Likes: 1
2019 GLS 450
Mercedes does not have specified interval for front differential fluid but you should change it at the same time as the rear differential fluid. Reason being, well the fluid does go bad (I seen report of front diff failures requiring rebuild and replacements in worse cases, not sure why MB doesn't have an interval for the front diff), transfer case fluid is also important, do it as well if you have a 9G it is separate from the transmission. Since you have 4MATIC, you want to do front, rear differential fluids and transfer case. If you want to delay changing the front differential fluid try not to delay it for more than 2 years or more than 75,000 miles whichever comes first.
MBWorld God!
Joined: Dec 2019
Posts: 32,406
Likes: 6,337
Thank you for the information! Do you happen to have the part number from FCP Euro for the transfer case fluid? I found the differential fluids. I assume it’s the same for the rear and front differential fluids. How many liters will I need to buy for the gear box and the differential fluids? Thank you, I appreciate it.
This should be the transfer case fluid needed 001989680313
Last edited by W205C43PFL; May 26, 2025 at 04:21 PM.
MBWorld God!
Joined: Dec 2019
Posts: 32,406
Likes: 6,337
As for the transfer case fluid blue or red, here is a thread that might help: https://mbworld.org/forums/gl-class-...34fe-blue.html
Junior Member
Joined: Aug 2024
Posts: 20
Likes: 1
2019 GLS 450
Newbie
Joined: Oct 2025
Posts: 4
Likes: 0
2018 GLS 450
Hi Pmdonca,
Was just wondering which Transfer Case Fluid you used on your 2018 GLS 450 9G.
I went to the dealer and asked for Fluid and they gave me ATF 3353 (A001 989 45 03 09)
Any Help will be appreciated.
Thanks
Was just wondering which Transfer Case Fluid you used on your 2018 GLS 450 9G.
I went to the dealer and asked for Fluid and they gave me ATF 3353 (A001 989 45 03 09)
Any Help will be appreciated.
Thanks
