Rear Differential Seals – remove axles? (with compendium of DIYs and helpful links)

[ElSabio182]

I’m getting ready to replace the rear differential output axle seals, trying to gauge how challenging a job it is. Getting the seals out and new ones properly aligned without scratching the inner surface seems like the most challenging part (I’ll probably end up buying the VAG alignment tool). Will be using a by-the-hour rented lift bay, so that’ll help.

One lingering question after reading through the DIYs…do I need to remove the axles or not? I saw a few posts by people having problems moving the loosened axles out of the way, and ending up having to pull the whole axle, which I would prefer not to do.

What I THINK the solution is (from additional searching) is to load up the axle/suspension to keep the axle from hanging and “pinching” against the diff. What’s the definitive word? Any other tricks or techniques for moving or compressing the axles? Since it’ll be on a lift, I’ll be using “tall-boy” jacks…best to support directly on the axle, or should I load the suspension from the wheel or control arm?

Thx!

PS: anyone know if the six axle flange bolts are M8 triple square, or M10 triple square??

PPS: And if it’s helpful to anyone in the future, here are all the resources I’ve dug up for doing the job. Should be a one-stop shop for anyone else searching in the future. Doesn’t seem like a job that should take toooo long…but I know those are famous last words!


HOW-TO REFERENCE LINKS:
DIY (for a B5 A4, pulls the entire differential out): http://www.audizine.com/forum/showth...ial-Axle-Seals
DIY (for a B6 A4, keeps axles installed): http://www.audizine.com/forum/showth...ial-axle-seals
DIY (for a C5 A6, keeps axle installed): http://www.audizine.com/forum/showth...al-replacement
DIY (for A8): http://www.audipages.com/Tech_Articl...placement.html

WHY I’M ASKING THIS QUESTION:
This guy had trouble moving the axles: http://www.audiworld.com/forums/a4-b...ement-2856115/
So did this guy: http://www.audizine.com/forum/showth...REAR-DIFF-seal
So did this guy….fixed problem by loading the suspension? http://www.audizine.com/forum/showth...al-Replacement

ASSORTED RELATED STUFF:
How to change differential fluid: http://www.audiworld.com/tech/misc33.shtml
How to check differential fluid levels and what kind of fluid to use: http://www.audizine.com/forum/showthread.php/254203
DIY for changing the INPUT seal, not the axle/output seals (B5 A4): http://www.audizine.com/forum/showth...ut-Flange-Seal
ECS Kit with Motul 300 fluid ($82): https://www.ecstuning.com/News/AUDI_...001/ES2538236/
ECS Kit with Redline 75w90 ($65): https://www.ecstuning.com/News/AUDI_...001/ES2580731/
New Mounting Bolts: https://www.ecstuning.com/Audi-B5_A4...tial/ES260073/
Individual OEM Axle Flange Seals ($25, cheaper aftermarket versions available): https://www.ecstuning.com/Audi-B5_A4...tial/ES266849/

Official VAG seal alignment tool thingy:
https://vw.snapon.com/specialtoolsde...itemid=2610007
http://www.samstagsales.com/vwaudi2.htm#Wheel_tool
http://www.zdmak.com/

[jsbs1991]

When I did mine last year I did not have to take out my axels, but they were hard to move out of the way. My car was on Jack stands, so for me to move the axles I jacked up the rear wheels to so I could move my axels out of the way. Also they are m8. And there will be a bolt holding the axel flange to the differential. I think it's a 6mm Allen. It's not a hard job. Also make sure to use some thread lock. Biggest problem I had was getting the axel to come off the flange. Mine was rusted together.

[ElSabio182]

Ok, so applying suspension load onto the wheels worked for you. I'm anticipating using a hammer to tap the axles out of the way, and will probably apply some penetrating oil, maybe a few days prior to doing the job if I can get at it.

And you just used thread-locker on the external flange bolts/heat shield bolts right? Not sure I'd want to put thread-locker on the 6mm allen bolt. And thanks for confirming M8.

[Silverstreak98]

I can also attest that getting the axle to separate from the flange was a huge PIA. Even with a hammer, I thought mine were never going to come undone. Definitely make sure you use a lot of penetrating oil on them well ahead of time to try and save yourself from that.

[jsbs1991]

What i did to get them to separate. Was I got in the car and put it in first gear since all the bolts were off it just popped off ,from me just releasing the clutch pedal a little with no throttle, I did not put any thread lock on the allen.