Tiptronic Rear Differential Oil Change

[JFP in PA]

Originally Posted by Roy_Josef

Any reason why the electric fluid pump as used in boats wouldn't work? Taking a look online seems like it would work perfectly. Snake the hose in, turn the pump on, suck out fluid then use a regular gear oil hand pump to pump a litre worth of new stuff in...

Any oil recommendations for the tiptronic diff? I know it's supposed to be 75W90 but can't find any info on the correct GL rating as in GL4 or GL5 or brand recommendations...Pelican sells "Titan" diff oil but I would rather use a Redline or Swepco product if available as I'm sure many of you reading this would too.

Chances are that a hose and pump will not get all the old oil and sediment out, so you may have to refill and dump several times to get everything. By that time, you could have pulled the axel and cover............

As for the best/correct gear oil, experience over the years had taught me that Porsche is prone to use very unusual and even unique gear box and diff oils, several major oil companies have openly admitted they do not have anything comparable because of the strange specs Porsche uses. As far as small blenders like Redline, Royal Purple, or Amsoil; while they have consistently claimed they have a matching product for just about everything, only problem is that most of the time they are misleading you with thinly veiled marketing hype; which is why we do not use any of their products..............

[favino1006]

JFP in PA,

Thanks for the info on what not to use... Now, drawing from your experience over the years; care to share what the best/correct gear oil IS?

[favino1006]

Hey Guys,

A follow-up:

I finished the fluid change this morning. Everything went pretty smoothly. I followed the excellent write-up that Andy put together on this forum along with the Pelican write-up. I let my trans. sit and drain overnight without the cover or filter on. I drained 4 1/2 liters total and then managed to put in 5 1/2. After starting up the car and taking it up to 40 C, I then drained a further 2 1/2 liters of partially contaminated fluid (in an effort to flush), then refilled 2 1/2 liters of new fluid back in. So all in all, I ran 7 liters of new fluid through the system but basically put 5 1/2 liters in. I then sealed everything up and went for a drive! The car is shifting through gears absolutely, noticeably smoother. It's awesome.

Now, on to the differential... What looks like it shouldn't be too much hassle, has just been ridiculous! I haven't been able to get the fill plug to break loose. The Bentley book says the plug torques at 22 ft lbs. I've easily put over a hundred on it trying to get it off, without any luck. It looks like it's got locktight or something similar on it and It's such a small space to work in! Anyhow, I'm going to go to an indie shop monday morning and see if those guys can get it open. I'm just amazed, lol. But, happliy, the creepy, guess-work part of the project is done! :dance:

[JFP in PA]

Originally Posted by favino1006

JFP in PA,

Thanks for the info on what not to use... Now, drawing from your experience over the years; care to share what the best/correct gear oil IS?

We get ours from Porsche..............

[JFP in PA]

From the factory, there is often a sealant like material on the plug that really makes difficult to remove the first time. Once it is loose, you will be fine. We clean the factory sealant off the treads and put a drop of anti seize on it before re-torque......

[favino1006]

Awesome. Thanks for the info. That plug is making me crazy, lol.

[Roy_Josef]

Just went through that this weekend. Best way to get the plug out is to pull off the diagonal body brace underneath, it's just a bolt and a couple of nuts. After that you can with the right combination of extensions and breaker bar get a nice 90 degree angle on your ratchet/breaker bar and get the plug out with NO PROBLEMS. I spent 20 minutes trying with the brace in place and couldn't do it. Pulling the brace took all of 2 minutes and after that it was as easy as a girl from Surrey...

[rp123]

Can someone point me to Andy's Tiptronic Rear Differential Oil Change write-up?