Today Is National Differential Fluid Day!

[gakali]

Well not really.

But I did finally get around to checking my front diff fluid. It's condition and level were making me paranoid. It was JJ's post about "a pile of goo for fluid" or something like that that made me wonder.

I really should have checked/replaced it when I had the tranny out for the chains. Crazy that there is no drain plug for it

Once the pendulum mount was out I could easily remove the fill plug with an extension from behind the frame. At 240,000 km the level was full, clean and smelled like gear lube. I chose not to replace it as I would need to devise some sort of way to suck it out through the hole. I highly doubt I could even get out half of it this way as space is limited. Forget about using the road speed sensor hole it wouldn't work on this tranny as far as I can tell. I'll just go with the "lifetime fill" thing for now.

At least now the paranoid visions of an oil starved diff. can be put to rest
_________________
Why do it? Because you can.

1999 Eurovan
2003 A4 Avant 1.8T Quattro
1992 W201 190e 2.3 Mercedes
2006 W220 S600 V12 Twin Turbo 5.5 Mercedes

[jjvincent]

We changed diff fluid in Audi 5000's for years because they needed it. We had a small copper pipe bent to wedge down into the diff and then sucked it out.

[JMB3]

I looked at mine today because I was under there for some other stuff. At 130,000 miles it was full and looked OK. I was able to suck out only about .5 liter with a MityVac. At least I was able to clean the magnet. Write-up in the wiki https://vweurovan.wikia.com/wiki/Final_Drive_or_Differential

[bcolins]

What is the recommended lubricant? 80W90 gear lube?

[Glenn]

[gesoffen]

Going on recollection here but I remember: API GL4 or GL5, 75W/90

[trunnion]

Service manual calls for:
Synthetic Gear Oil 75W90 part number G 052 145 S2

[VanGeek]

Just performed this today.
My 01 weekender has about 88K on the clock.
Pulled about 0.6 Liters out of it using a vacuum pump and a plastic hose aimed down to the bottom of the fill area.

The gear oil I removed was brown and not sludgy but definitely looked very used/tired. It also seemed a tad low -- below the fill port.

Found the expected (but a little disturbing) metal shavings off the magnetic plug and cleaned it off.

Accepted ~.75 liters on the refill which supports my prior guess that it was a little low. Not clear if this was necessary but it wasn't especially difficult either. Felt good to add the much cleaner and fresher synthetic oil to replace what was removed.

[kourt]

I did the same on my 2001 EVC on Saturday. 235,000 miles and I'm pretty sure this is the original differential oil. Same process as you. I think I will do it again in a year to get more of an exchange on the oil, since I think my suction pump could not reach the bulk of it.

I used this cheap fluid pump to get the old fluid out and put the new fluid in. It worked well.

I used some Mobil 1 75W90 gear oil left over from my Vanagon days to refill the differential to the point of spillage from the filler hole, and then I replaced the plug.

My workspace is on a slight slope, so it is rare that I have the van jacked to the point of being level enough for accurate work on the differential. However, I was working on the from bushings and noticed it was very level, so I went ahead and got this item out of the way.

kourt

[hcr]

[kourt]

Maybe. But it's a huge hex plug--larger than any key offered in a standard Allen key set. I used a 17mm Allen that accepts a 3/8" square ratchet driver. You'll need a lot of torque on that plug if it's never been opened. So save yourself the trouble and just take the pendulum mount off.

Removing the pendulum is part of the process of removing the upper control arms/torsion bars, so I was already halfway there.

kourt

[hcr]

Sounds good, thanks.

Charles

[gesoffen]

[bigfoot_ev]

I'm right in the middle of this maintenance and I can't seem to find the lucky spot for my extraction tube to go down into the final drive. At the moment, I can only extract about 1/4 qt. I even switched from a transfer pump to my mityvac which has a much smaller OD, small enough to fit over brake bleed nipple.

Looking at the erwin diagrams I wonder if I'm getting hung up on the differential support for the output shaft. Maybe I rotate a wheel?

Any tips on getting more oil out?
_________________
2003 Westfalia Weekender, AXK, 01P

[Endopotential]

Sounds like you're doing all the right things. And from all your prior work on the van, you definitely have enough tinkering credentials.

Which leaves the scary prospect that 1/4 quart really was all that was left in your diff?

I didn't do much more than take off the pendulum mount, which BTW is not easy to get back in place without a second hand or lot of force.
_________________
2002 Eurovan Weekender

[bigfoot_ev]

[krusovice]

I just changed mine yesterday and when I pulled the plug it seems like a lot came out on its own. I have no idea how it was so full. And no matter how I tried, it kept spilling out when I refilled. Logically, I realize I must have added enough if it’s coming out of the filler but it just seems odd to me.

Why on earth is there not a drain as well?
_________________
1984 Vanagon 1.9/4 speed
2001 Eurovan Camper

[bigfoot_ev]

[krusovice]

I wasn’t clever enough to measure it. I did pump some out before pumping some in, but what surprised me was how much came out right when I pulled the plug. I would have thought next to none should come out of a properly filled diff.
_________________
1984 Vanagon 1.9/4 speed
2001 Eurovan Camper