i need a diy on differential seal removal and flush

well, while im doing my hr springs installed, i noticed a leak coming from the output differential seal, anyone can confirm me that the problem is the seal and not the differential itself? dont get any noise from differential.. my shaft is out and i will replace a leaky boot, and would like to fix also the diff leak... anyone know how to get the seal out? is this the good ^part number to order a new one?999-113-347-40-M204

PM'd you

The front diff seals on my turbo looked the same. I was replacing the CV boots when I noticed the slow leak. I tried for and hour to get it our with regular tools, but i just bent the crap out of it. You have to be careful not to allow the spring inside the seal to pop out and back into into the diff case. I ended up renting a ring puller from a local part store. Came out in 1 min. Installing the new one is tricking because they are easy to damage...they have to go in exactly square due to the tolerances of the opening. The key is to make sure the you have something that is the same diameter as the cup that you can seat the ring with. I bought a large socket that was the same OD size as the new seal (1.75"). I put some white lithium grease on the outside of the seal, lined it up and gave it 2 wraps with a rubber mallet...it went right in.

I did do the flush and fill after I reinstalled the shafts last fall. I pulled the plug on the bottom of the case and drained it. It helps to have the car up in front and let gravity take out the fluid. My understanding is that the case only holds enough fluid to fill it to the bottom of the filler plug opening--it is on the side of the case. It makes it hard to overfill. I used OEM fluid and a hand pump filler. After I let it drain completely I put the drain plug back in and pumped in about 50cc and then let it drain again...just to make that I got out any containments. My fluid was clean, no metal or dark colors... it was a bit cloudy. To make sure I was putting back the correct amount I measured out the Spec amount into a clean container and then added an extra 25cc to account for what would be left in the pump filler. I jacked the car up in the rear so that it was parallel front to back and checked the side filler plug with my small finger. The fluid was at the bottom of the plug opening...correct amount. After I was done I spun the wheels with the car in neutral just to make sure that internals were coated and that any air would work itself out before I put power to the wheels. I check the level again---I am a bit **** about these things. All is well 5k later... no leaks.

thanks for the info jrock, i will get myself a ring puller, tell me, how do you remove the circle part that cover the seal? is the c4s seal the same as a turbo?

NP--- I started out here on dial up in 2001... learning everything I could about these cars. I found nearly every answer to every question on Rennlist. This is an awesome resource. I have been mostly active on another site for a couple of years, but I aways gravitate back when I have tough technical questions. I have wanted to own a Porsche since I was 10. One of my father's friend owned a '74 Canary Yellow 911... I was hooked. I feel blessed everyday when I open my garage door. -- The orange ring that surrounds the shaft is a cup seal. The cup is metal with rubber coating that has a flange/seal on the inside that is held tight against the shaft w/spring. The orange part is the cover and the seal all in one. It appears they are the same for both the 996/c4/c4s and the turbo. http://www.pelicanparts.com/cgi-bin/...2001-05)%20%20

the part thats the 6 shaft bolts goes in, the part after the seal it self, how do you remove it to have access to the seal.. ????

I predict another unfinished spring car for Paseb...

hahaha, i always start too late my project in spring come help me it will go quicker

I removed the entire half shaft w/o removing the bolts. A quick tug and the whole assembly came out. There is a retaining ring on end of the splines ... I replaced this before I re-installed, but it came out without any effort. Not sure if this the correct procedure.

damn, both my shafts are already out and i still have the part covering the seal, what to do?

Not sure how easily the can be pulled with out the leverage of the entire shaft. Anyone else know how to remove? I do not want to tell Seb to jerk them out and have him damage the internals.

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hehehe, anyone??? i need to have access to those damn seals!!!

there is a snap ring that holds them in. Just get a quick hard pull and they should pop out. Rick 99 996C4 87 944S

OP - Did you notice any symtoms because of the leak? Under heavier acceleration would it stutter?

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not really, car is running really good, i just discovered the leak cause i removed the black underneath panel i shouldnt lol

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the snap ring will pop out by itself or i need to remove that snap ring that i never seen hehe

Sorry, snap ring is not the correct term, it's circlip. It sits in a groove on the half shafts and compresses into the groove to slide out of the front diff pumpkin. Rick 99 996C4 87 944S

When I took my half shafts out they slid right out without much pressure at all. This happened when I was installing my PSS10's. Never saw, or at least noticed any clips.

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You were able to pull the entire driveshaft out of the front differential without removing any other parts? I wouldn't think there would be enough wiggle room? Or did you have the front suspension off of the car to give you all the room you needed?

Has anyone replaced their front seals recently? Once the weather gets a little warmer, I will be replacing the fluid, and am considering replacing the seals as well. Two years ago when I last removed the front underbody panel I found a little bit of seepage at both front seals. I had the dealer look at it, they weren't concerned, fluid level was full, (but quoted me anyways I think ~$900 to replace). Since I will be in that area anyways, I figure now might be a good time to replace, and see if the leak is any worse 2 years later. I'm not sure what's normal for a C4, but the AWD did seem to work this winter. Starting from a dead stop it seemed most noticeable as I thought I could feel the rears spin a few rotations, then the fluid would get warm enough to send more power to the front then it would really grip. Sometimes if I was being aggressive with the throttle I could hear a small clunking noise, and if it was very slippery (pure ice) and I was very aggressive with the throttle, it would vibrate a little, felt like driving on washboard. I've looked at the Bentley book, they use Porsche tool 9537 to install the seals. I figure anything with that OD should work. They also use an axle press tool to remove the half shaft from the upright, is this tool really needed? Finally, they torque the axle to 340 lb-ft! I think my torque wrench only goes to 250 lb-ft, any tips to get the axle torqued? Thanks!

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Rent a gear torque multiplier from a tool rental shop. My son and I had to rent one to put the flywheel back on his RX-8. http://www.torquetools.com/Torque-Pr...ltipliers.html

Good idea to rent, I'll have to check with my local auto parts store. The only tool I've had to rent before has been gear pullers.

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See attachment. It references the rear differential for removing the halfshaft flange (2-bolt method). But the procedure is the exact same for the front differential. I did this and it worked like a charm. 30 min job seal replacement. Good luck.

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Well, I'm having issues posting the attachment. Maybe this will work.

OK. Not sure if this is helpful but I am in the processed of replacing the final drive shaft seals. As said already, I removed the drive shaft by putting in two bolts on opposite sides of the drive shaft and turning them in slowly and alternating to leverage out the shaft. I would think that if it just pulls out the seal might need to be replaced BUT I certainly am no expert. Anyway replace the circlip when reinstalling. Now as to removal of the seals, I am still trying a lot of pulling but not out yet. Any additional thought would be appreciated.

Im doing a similat thing. I cant get the drive shaft bolts off.Or the fill plug . They are very tight. What are the torque values suposed to be?