Front and Rear Diff and Transfer Case Fluid Change
Thread Starter
Junior Member
Joined: Apr 2020
Posts: 49
Likes: 12
2014 GL450
Front and Rear Diff and Transfer Case Fluid Change
2014 GL450
77,280 miles
Did this job yesterday. Not bad once all the materials were on hand and the skid plate was removed.
Front and rear differential: Removed fill plug first. Drained fluid for 30 minutes, refilled with Valvoline 75w90 about 1.5 bags each. Refill until it comes out the fill hole. Rear needed a 4" piece of tubing from bag to fill hole for access. Rubber O-rings looked good and I couldn;t source them so reused mine. Access to the plugs wasn't great. I used an open end wrench to turn the hex shaft on the socket for the ones that were hidden.
Transfer Case: Removed fill plug first. Drained fluid for 30 minutes, refilled with MB ATF134FE blue about 1/2 liter. Refill until it comes out the fill hole. 2 copper crush washers were replaced with new.
Access to these was easy. Tightened the plugs to 18 nm.
You will need an 8MM 6-point hex and a 14MM 6-point hex for drain and fill plugs, 3 bags of gear oil and a liter/quart of ATF 134FE.
Rear diff fluid was clean and near original color.
Front Diff was very dark.
Transfer case was also very dark.
I was hearing a whine that coincided with rpms and gears and also feeling a coinciding sensation in the steering wheel. Those seem mostly gone now. Maybe it's just me.
Not a bad job for someone in their driveway though.
77,280 miles
Did this job yesterday. Not bad once all the materials were on hand and the skid plate was removed.
Front and rear differential: Removed fill plug first. Drained fluid for 30 minutes, refilled with Valvoline 75w90 about 1.5 bags each. Refill until it comes out the fill hole. Rear needed a 4" piece of tubing from bag to fill hole for access. Rubber O-rings looked good and I couldn;t source them so reused mine. Access to the plugs wasn't great. I used an open end wrench to turn the hex shaft on the socket for the ones that were hidden.
Transfer Case: Removed fill plug first. Drained fluid for 30 minutes, refilled with MB ATF134FE blue about 1/2 liter. Refill until it comes out the fill hole. 2 copper crush washers were replaced with new.
Access to these was easy. Tightened the plugs to 18 nm.
You will need an 8MM 6-point hex and a 14MM 6-point hex for drain and fill plugs, 3 bags of gear oil and a liter/quart of ATF 134FE.
Rear diff fluid was clean and near original color.
Front Diff was very dark.
Transfer case was also very dark.
I was hearing a whine that coincided with rpms and gears and also feeling a coinciding sensation in the steering wheel. Those seem mostly gone now. Maybe it's just me.
Not a bad job for someone in their driveway though.
Member
Joined: Jul 2002
Posts: 148
Likes: 17
From: NJ, USA
2013 GL450, 2023 Tesla Model Y LR, 2024 Outback L XT
lifting the truck
Can I ask how you got the car up and/or how you got underneath the car? did you raise the air suspension and that was enough? Thanks.
Thread Starter
Junior Member
Joined: Apr 2020
Posts: 49
Likes: 12
2014 GL450
I jacked the car up and put it on 4 jack stands. I would never trust the air suspension alone for working under the car. The job can be done without raising the car at all if you are small enough. The front skid plate is the hardest part of the job and that was where the extra height was needed for me. I believe it was an 8mm socket, maybe 9mm.
Member
Joined: Oct 2011
Posts: 105
Likes: 39
From: SC
2015 GL350, 2013 GL350, 2002 ML320, 1983 E300TD-D
I jacked the car up and put it on 4 jack stands. I would never trust the air suspension alone for working under the car. The job can be done without raising the car at all if you are small enough. The front skid plate is the hardest part of the job and that was where the extra height was needed for me. I believe it was an 8mm socket, maybe 9mm.
Also, the differentials get changed about every 50k. I just get them done along with the transmission service. Doesn’t add much to the bill. Has ~250k on it now and running, driving & operating like a top.
Member
Joined: Nov 2014
Posts: 150
Likes: 32
GL350
The transfer case is so easy I do it about every 4th oil change which is ~20k miles. Overkill yes but I have had to replace the chain due to the prior owners mechanic (Dealership) not changing nor checking the fluid. When I got the chain started skipping a tooth here & there within 10-15k miles. Pulled the drain plug & got about a thimble full of black fluid. I would love to know how the fluid leaked out because I’ve never seen the case drip a single drop.
Also, the differentials get changed about every 50k. I just get them done along with the transmission service. Doesn’t add much to the bill. Has ~250k on it now and running, driving & operating like a top.
Also, the differentials get changed about every 50k. I just get them done along with the transmission service. Doesn’t add much to the bill. Has ~250k on it now and running, driving & operating like a top.
Good to change the t-case fluid regularly but the chain skipping is unrelated to the fluid. Although MB doesn't put it in the manual the transfer case chain has a 60K mile lifespan and is a wear item.
Member
Joined: Oct 2011
Posts: 105
Likes: 39
From: SC
2015 GL350, 2013 GL350, 2002 ML320, 1983 E300TD-D
Good to know, thanks for sharing. The chain is actually easy to change, almost as easy as changing the fuel filter, lol. I am at 100k on the replacement chain so I will add that to my list of stuff to do in the spring. Funny that this chain needs to be replaced at 60K and the chain in my 2002 ML has 299,497K on it and gets used like a farm truck, hard. The 02 ML is my work/tow vehicle. It isn’t out of the question for me to tow 10K+ pounds with it and not just around the corner either. Yeah I know that is double the tow rating of the vehicular. The chain in the ML has never been changed. Obviously it's spec’d much better than the chain in the GL350.
