Tiptronic Rear Differential Oil Change

[jcb986]

The TIP takes Pensotin ATF-1 and the final drive takes a 70-90 weight gear oil. I just did my service for the TIP. It took 6 liters, some use up to 7 liters. Next is the final drive oil change...I like the electric pump idea.

[JFP in PA]

Sorry guys, but the Tip equipped cars require that you pull an axel and side cover to drain the diff, that is the way Stuttgart designed it................

[Roy_Josef]

Originally Posted by JFP in PA

Sorry guys, but the Tip equipped cars require that you pull an axel and side cover to drain the diff, that is the way Stuttgart designed it................

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.

[favino1006]

Hey Guys,

A couple details: I bought the ZF ATF fluid that pelican sells. If you search their site for Esso/Mobil LT 71141 for AT Boxsters, two products show up; Pensotin ATF-1 and ZF ATF. The ZF cost just a little more. I went with it simply because the trans. was built by ZF. There wasn't any product number listed on the site that I saw. However, the fluid showed up today and here's what the containers have to say:

ZF-LifeguardFluid5
ATF
21010N28
Semi-synthetic high performance oil for use in 5-speed automatic transmissions, for cars only.

I, as well, haven't found any specs. regarding the GL rating for the rear diff. oil. My bentley book simply specs. "Hypoid gear oil SAE 75W90". I'm thinking of using Royal Purple product. The local auto part store has small electric pumps for rent for removing the oil. I'm going that route and not pulling the drive axle.

Alright, I'm diving into this change first thing in the a.m. I'll definitely post when I'm done!
-ian

[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......