just replaced my transfer case- change your fluid!
Senior Member
Joined: Feb 2011
Posts: 350
Likes: 106
From: Palo Alto, CA
2011 GL 350, P1 Package, HID headlamps, Blind spot assist, Parktronic, Wood steering wheel
Ok I just completed four services this afternoon - new v-belt, and drained and refilled the transfer case and both front and rear differentials.
Truck has roughly 60,000 miles on it. I do tow an Airstream with my GL, not sure what impact this might have.
The transfer case fluid looked ok. Still a bit red in color. The fluid in the differentials were both brown to black in color.
Swapping out the fluids took me a lot longer than the other folks have posted here - I would say two hours start to finish for all three. It was not hard at all - it just took a while to drain, refill and clean up in each of the three areas.
A couple of things not noted in the other posts.
I put the air-matic suspension in the "raised" position before I started. This gave me enough clearance under the truck that I was comfortable working without putting the truck up on stands.
You have to remove the plastic cover from underneath the front differential to get to it. This is the same cover you remove if you have done the transmission service before. It comes out easily by removing about a half dozen hex-head screws.
I shopped on-line at Pelican Parts to get the exact weights and specs of differential fluids specified by Mercedes. So I bought two liters each of the front diff fluid and the rear diff fluid, and one liter of ATF for the transfer case.
For the rear differential, I bought Fuchs - SAE 75W-85 - MBZ Approval: 235.7 differential oil. It required about 1.5 liters.
For the front differential, I bought Liquid Moly - SAE 85W-90 (MBZ Approval: 235.0) differential oil. It required about 1.5 liters.
For the transfer case, I bought Fuchs ATF 134 - the service required 0.5 liters.
I don't see how you could cram in much more than 1/2 liter of ATF into the transfer case. I jacked up the truck on the front passenger side as another poster suggested, and it didn't seem to make much of a difference in how much fluid I could get into the TC. The fluid immediately streams right back out the fill hole, and I'm just not fast enough to trap an extra couple of milliliters in there.
Truck has roughly 60,000 miles on it. I do tow an Airstream with my GL, not sure what impact this might have.
The transfer case fluid looked ok. Still a bit red in color. The fluid in the differentials were both brown to black in color.
Swapping out the fluids took me a lot longer than the other folks have posted here - I would say two hours start to finish for all three. It was not hard at all - it just took a while to drain, refill and clean up in each of the three areas.
A couple of things not noted in the other posts.
I put the air-matic suspension in the "raised" position before I started. This gave me enough clearance under the truck that I was comfortable working without putting the truck up on stands.
You have to remove the plastic cover from underneath the front differential to get to it. This is the same cover you remove if you have done the transmission service before. It comes out easily by removing about a half dozen hex-head screws.
I shopped on-line at Pelican Parts to get the exact weights and specs of differential fluids specified by Mercedes. So I bought two liters each of the front diff fluid and the rear diff fluid, and one liter of ATF for the transfer case.
For the rear differential, I bought Fuchs - SAE 75W-85 - MBZ Approval: 235.7 differential oil. It required about 1.5 liters.
For the front differential, I bought Liquid Moly - SAE 85W-90 (MBZ Approval: 235.0) differential oil. It required about 1.5 liters.
For the transfer case, I bought Fuchs ATF 134 - the service required 0.5 liters.
I don't see how you could cram in much more than 1/2 liter of ATF into the transfer case. I jacked up the truck on the front passenger side as another poster suggested, and it didn't seem to make much of a difference in how much fluid I could get into the TC. The fluid immediately streams right back out the fill hole, and I'm just not fast enough to trap an extra couple of milliliters in there.
Last edited by ddruker; Sep 18, 2019 at 12:53 PM.
Member
Joined: Dec 2010
Posts: 115
Likes: 5
97 s320
Ok I just completed four services this afternoon - new v-belt, and drained and refilled the transfer case and both front and rear differentials.
Truck has roughly 60,000 miles on it. I do tow an Airstream with my GL, not sure what impact this might have.
The transfer case fluid looked ok. Still a bit red in color. The fluid in the differentials were both brown to black in color.
Swapping out the fluids took me a lot longer than the other folks have posted here - I would say two hours start to finish for all three. It was not hard at all - it just took a while to drain, refill and clean up in each of the three areas.
A couple of things not noted in the other posts.
I put the air-matic suspension in the "raised" position before I started. This gave me enough clearance under the truck that I was comfortable working without putting the truck up on stands.
You have to remove the plastic cover from underneath the front differential to get to it. This is the same cover you remove if you have done the transmission service before. It comes out easily by removing about a half dozen hex-head screws.
I shopped on-line at Pelican Parts to get the exact weights and specs of differential fluids specified by Mercedes. So I bought two liters each of the front diff fluid and the rear diff fluid, and one liter of ATF for the transfer case.
For the rear differential, I bought Fuchs - SAE 75W-85 - MBZ Approval: 235.7 differential oil. It required about 1.5 liters.
For the front differential, I bought Liquid Moly - SAE 85W-90 (MBZ Approval: 235.0) differential oil. It required about 1.5 liters.
For the transfer case, I bought Fuchs ATF 134 FE - the service required 0.5 liters.
I don't see how you could cram in much more than 1/2 liter of ATF into the transfer case. I jacked up the truck on the front passenger side as another poster suggested, and it didn't seem to make much of a difference in how much fluid I could get into the TC. The fluid immediately streams right back out the fill hole, and I'm just not fast enough to trap an extra couple of milliliters in there.
Truck has roughly 60,000 miles on it. I do tow an Airstream with my GL, not sure what impact this might have.
The transfer case fluid looked ok. Still a bit red in color. The fluid in the differentials were both brown to black in color.
Swapping out the fluids took me a lot longer than the other folks have posted here - I would say two hours start to finish for all three. It was not hard at all - it just took a while to drain, refill and clean up in each of the three areas.
A couple of things not noted in the other posts.
I put the air-matic suspension in the "raised" position before I started. This gave me enough clearance under the truck that I was comfortable working without putting the truck up on stands.
You have to remove the plastic cover from underneath the front differential to get to it. This is the same cover you remove if you have done the transmission service before. It comes out easily by removing about a half dozen hex-head screws.
I shopped on-line at Pelican Parts to get the exact weights and specs of differential fluids specified by Mercedes. So I bought two liters each of the front diff fluid and the rear diff fluid, and one liter of ATF for the transfer case.
For the rear differential, I bought Fuchs - SAE 75W-85 - MBZ Approval: 235.7 differential oil. It required about 1.5 liters.
For the front differential, I bought Liquid Moly - SAE 85W-90 (MBZ Approval: 235.0) differential oil. It required about 1.5 liters.
For the transfer case, I bought Fuchs ATF 134 FE - the service required 0.5 liters.
I don't see how you could cram in much more than 1/2 liter of ATF into the transfer case. I jacked up the truck on the front passenger side as another poster suggested, and it didn't seem to make much of a difference in how much fluid I could get into the TC. The fluid immediately streams right back out the fill hole, and I'm just not fast enough to trap an extra couple of milliliters in there.
PLEASE never use the air suspension to raise vehicle for working on it..
if a airbag fails the car will come crushing down on you
Senior Member
Joined: Feb 2011
Posts: 350
Likes: 106
From: Palo Alto, CA
2011 GL 350, P1 Package, HID headlamps, Blind spot assist, Parktronic, Wood steering wheel
You are right, this is good advice - and it takes no work to put your jack stands underneath the frame to protect you.
I was more focused on the part about using the airmatic to raise the truck enough to work under it instead of using a jack to raise it.
I was more focused on the part about using the airmatic to raise the truck enough to work under it instead of using a jack to raise it.
Senior Member
Joined: Jul 2010
Posts: 275
Likes: 18
2010 GL550, 2013 C63
After much debate and looking around I decided to go with 85W-90 for both front and back diffs even though supposedly 75W-85 is now the recommended weight. Dont think higher weight will hurt anything and I do occasional towing with it so higher weight should be better. Have another 2k miles before next oil change and will do the whole job then.
Senior Member
Joined: Oct 2009
Posts: 288
Likes: 7
2010 GL450
Hey guys. I know this is a old post. But I'm replacing my transfer case with a used one and I wanted to change the oil while it was out of the car. My question is about the oil. Many people say MB ATF 134 is red in color but when searching eBay all the 134's say they are blue in color. Is it supposed to be blue or red?
And should I put .75qt or .5qt?
And should I put .75qt or .5qt?
Last edited by jandmtv; Jun 6, 2016 at 09:01 AM.
Senior Member
Joined: Oct 2009
Posts: 288
Likes: 7
2010 GL450
Ok I just completed four services this afternoon - new v-belt, and drained and refilled the transfer case and both front and rear differentials.
Truck has roughly 60,000 miles on it. I do tow an Airstream with my GL, not sure what impact this might have.
The transfer case fluid looked ok. Still a bit red in color. The fluid in the differentials were both brown to black in color.
Swapping out the fluids took me a lot longer than the other folks have posted here - I would say two hours start to finish for all three. It was not hard at all - it just took a while to drain, refill and clean up in each of the three areas.
A couple of things not noted in the other posts.
I put the air-matic suspension in the "raised" position before I started. This gave me enough clearance under the truck that I was comfortable working without putting the truck up on stands.
You have to remove the plastic cover from underneath the front differential to get to it. This is the same cover you remove if you have done the transmission service before. It comes out easily by removing about a half dozen hex-head screws.
I shopped on-line at Pelican Parts to get the exact weights and specs of differential fluids specified by Mercedes. So I bought two liters each of the front diff fluid and the rear diff fluid, and one liter of ATF for the transfer case.
For the rear differential, I bought Fuchs - SAE 75W-85 - MBZ Approval: 235.7 differential oil. It required about 1.5 liters.
For the front differential, I bought Liquid Moly - SAE 85W-90 (MBZ Approval: 235.0) differential oil. It required about 1.5 liters.
For the transfer case, I bought Fuchs ATF 134 FE - the service required 0.5 liters.
I don't see how you could cram in much more than 1/2 liter of ATF into the transfer case. I jacked up the truck on the front passenger side as another poster suggested, and it didn't seem to make much of a difference in how much fluid I could get into the TC. The fluid immediately streams right back out the fill hole, and I'm just not fast enough to trap an extra couple of milliliters in there.
Truck has roughly 60,000 miles on it. I do tow an Airstream with my GL, not sure what impact this might have.
The transfer case fluid looked ok. Still a bit red in color. The fluid in the differentials were both brown to black in color.
Swapping out the fluids took me a lot longer than the other folks have posted here - I would say two hours start to finish for all three. It was not hard at all - it just took a while to drain, refill and clean up in each of the three areas.
A couple of things not noted in the other posts.
I put the air-matic suspension in the "raised" position before I started. This gave me enough clearance under the truck that I was comfortable working without putting the truck up on stands.
You have to remove the plastic cover from underneath the front differential to get to it. This is the same cover you remove if you have done the transmission service before. It comes out easily by removing about a half dozen hex-head screws.
I shopped on-line at Pelican Parts to get the exact weights and specs of differential fluids specified by Mercedes. So I bought two liters each of the front diff fluid and the rear diff fluid, and one liter of ATF for the transfer case.
For the rear differential, I bought Fuchs - SAE 75W-85 - MBZ Approval: 235.7 differential oil. It required about 1.5 liters.
For the front differential, I bought Liquid Moly - SAE 85W-90 (MBZ Approval: 235.0) differential oil. It required about 1.5 liters.
For the transfer case, I bought Fuchs ATF 134 FE - the service required 0.5 liters.
I don't see how you could cram in much more than 1/2 liter of ATF into the transfer case. I jacked up the truck on the front passenger side as another poster suggested, and it didn't seem to make much of a difference in how much fluid I could get into the TC. The fluid immediately streams right back out the fill hole, and I'm just not fast enough to trap an extra couple of milliliters in there.
Senior Member
Joined: Oct 2009
Posts: 288
Likes: 7
2010 GL450
Ok so after much research and a phone call to Mercedes Benz USA customer service line here is the info I got.
Transfer case oil - use the red colored MB ATF 143 oil. Not the blue 134. This came from MB USA!
Diff oil - front and back diffs should have the same oil weight. Mercedes recently changed from recommending 85W-90 to 75W-85 for both the front and rear diffs. Approx 3L is all you will need to service both the front and rear.
85w-90 was deemed to thick by MB engineers I was told. So now they only recommend using 75W-85.
Hope this helps.
Transfer case oil - use the red colored MB ATF 143 oil. Not the blue 134. This came from MB USA!
Diff oil - front and back diffs should have the same oil weight. Mercedes recently changed from recommending 85W-90 to 75W-85 for both the front and rear diffs. Approx 3L is all you will need to service both the front and rear.
85w-90 was deemed to thick by MB engineers I was told. So now they only recommend using 75W-85.
Hope this helps.
Member
Joined: Oct 2016
Posts: 247
Likes: 55
'07 GL450
Thanks to everyone who has posted on this thread. One of the most informative and useful ones here!
I just changed my transfer case fluid at 48k miles. I figure it's good preventive maintenance even if not fully needed. Real easy access. Took longer to jack up front for draining, then the rear for filling than anything. Old fluid was light and flowed easily, but brown. I replaced w/ Redline D6 ATF as I really like their products. I'll probably do the differentials soon. Should have done them at the same time, but it sounds like they can go longer w/out a change. Hopefully they are aren't low.
I just changed my transfer case fluid at 48k miles. I figure it's good preventive maintenance even if not fully needed. Real easy access. Took longer to jack up front for draining, then the rear for filling than anything. Old fluid was light and flowed easily, but brown. I replaced w/ Redline D6 ATF as I really like their products. I'll probably do the differentials soon. Should have done them at the same time, but it sounds like they can go longer w/out a change. Hopefully they are aren't low.
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Member
Joined: Oct 2016
Posts: 247
Likes: 55
'07 GL450
I presume they're fine, but just in case they're under-filled from the factory, it's easy & cheap preventive maintenance.
Reading this up-thread got me thinking...
Reading this up-thread got me thinking...
Junior Member
Joined: Jan 2017
Posts: 61
Likes: 7
08 R350
Ok so after much research and a phone call to Mercedes Benz USA customer service line here is the info I got.
Transfer case oil - use the red colored MB ATF 143 oil. Not the blue 134. This came from MB USA!
Diff oil - front and back diffs should have the same oil weight. Mercedes recently changed from recommending 85W-90 to 75W-85 for both the front and rear diffs. Approx 3L is all you will need to service both the front and rear.
85w-90 was deemed to thick by MB engineers I was told. So now they only recommend using 75W-85.
Hope this helps.
Transfer case oil - use the red colored MB ATF 143 oil. Not the blue 134. This came from MB USA!
Diff oil - front and back diffs should have the same oil weight. Mercedes recently changed from recommending 85W-90 to 75W-85 for both the front and rear diffs. Approx 3L is all you will need to service both the front and rear.
85w-90 was deemed to thick by MB engineers I was told. So now they only recommend using 75W-85.
Hope this helps.
Spec 236.15 is blue
Last edited by tru1man; Feb 20, 2017 at 05:18 PM.
Senior Member
Joined: Jan 2013
Posts: 421
Likes: 57
2021 V167
I change mine every other oil change. Really easy and quick with a pump.
Senior Member
Joined: May 2013
Posts: 437
Likes: 84
From: Espoo, Finland
2012 GL 350
Yes, that's a vent tube. The fluid gets very hot, and most liquids (especially petroleum based) expand when they are hot. That tube allows the fluid to expand without spilling onto the ground.
Member
Joined: Oct 2016
Posts: 247
Likes: 55
'07 GL450
I was presuming it was a vent, thanks for confirming! Changing out the diff fluids in two weeks!
Member
Joined: Oct 2016
Posts: 247
Likes: 55
'07 GL450
Just did the diffs this evening. Easy access, just used an 8mm hex key and it cleared the exhaust fine in the rear. Fluid was clean on both @ 50k miles. Probably didn't need to do. There was a bit of fine black powdery build up on the drain plugs. Almost like graphite.
I was only able to get about 1.25 qts in each before they started overflowing. Should I go back after driving and try to top off a bit? Just seems like it would be really hard to get another .25 qt in. Oh, and too late now, but do the o-rings need to be replaced, or are they re-usable? Hope so...
I was only able to get about 1.25 qts in each before they started overflowing. Should I go back after driving and try to top off a bit? Just seems like it would be really hard to get another .25 qt in. Oh, and too late now, but do the o-rings need to be replaced, or are they re-usable? Hope so...
Member
Joined: Oct 2016
Posts: 247
Likes: 55
'07 GL450
Super Member
Joined: Aug 2008
Posts: 528
Likes: 20
From: Chicago IL
X166 gls450 2017
One good tip to fill the fluid I saw online was to make a hole for tube-insert in the cap, and a small hole to force pressurized air from compressor into the bottle - I found it much easier to pump the fluid this way..
Newbie
Joined: Mar 2017
Posts: 6
Likes: 5
2008 GL 450
I work at a transmission repair shop and just replaced the chain in the transfer case in My 08 GL450. it has the single speed non-offroad performance case and the only wear inside the unit at 170k was the chain and the chain guide had a broken mounting boss.
this being My personal car I am testing a theory. a few notes from this repair, the plastic guide I feel was damaged from the worn/loose chain so I drilled and tapped the holes for longer bolts and reinstalled. in the single speed unit there are only bearings and a chain for moving parts,I feel that .5 lt is not enough lube and atf is a bit light. I forced 1 liter of 0w20 synthetic engine oil through the fill hole and reinstalled the plug.
In Our shop We do a lot of American 4x4 trucks and have found that a little over fill and using Synthetic engine oil in place of atf has extended the life of the units.
side note: on the 2 speed units with clutches, I would only recommend using engine oil at Your own risk.
I will watch My theory over the next few miles and see what happens.
this being My personal car I am testing a theory. a few notes from this repair, the plastic guide I feel was damaged from the worn/loose chain so I drilled and tapped the holes for longer bolts and reinstalled. in the single speed unit there are only bearings and a chain for moving parts,I feel that .5 lt is not enough lube and atf is a bit light. I forced 1 liter of 0w20 synthetic engine oil through the fill hole and reinstalled the plug.
In Our shop We do a lot of American 4x4 trucks and have found that a little over fill and using Synthetic engine oil in place of atf has extended the life of the units.
side note: on the 2 speed units with clutches, I would only recommend using engine oil at Your own risk.
I will watch My theory over the next few miles and see what happens.
