Differential and Transfer Case Oil Change

[working4it]

I originally posted this on rennlist.com but thought I would post it here as well...

Was really easy to do other than trying to get at the fill plug for the front Diff. My socket wouldn't fit and I happen to have the correct allen wrench. Huge difference in sound...

Rennlist thread..

Changed the Differential Oil and Transfer Case Oil Fluid

[wvicary]

Any specs on the oil used. What type/amount/price?

[SWFLHOMES]

Question: I have the noisey differential problem and wanted to change the fluid to see if it helps. I see you removed the top drain screw. Did you have to remove the bottom to drain as well? Please tell me the difference between the bottom and top tubes. I would guess the top tube you are filling the diff back up but what are you doing with the bottom tube? And as vicary asked: fluid, amount and cost?

Thanks

[working4it]

Its realatively easy to do. The top pictures are the front differential(clear gold fluid) and the bottom ones are for the middle transfer case(red).

The transfer case and Transmission use ATF (Esso ATF LT 71141) Esso is now apart of Mobil and Mobil 1 Sythetic now meets 71141 spec. After several emails directly with mobil rep he finally admitted to me "because of licensing agreements we are not allowed to say recommended" but can say meets the 71141 spec(which it does on the bottle). So i felt safe using it. For the Front and Rear differential I also used Mobil 1 LS 75w-90 (which also meets the LSD transmissions) I would have used AMSOIL but didn't want to wait as I was fixing the brake sensor. Per Porsche website the Differential uses Burmah SAF AG4 75w-90. On all 3 I flushed it out by pumping a few extra squirts and letting it drain out. All 3 are much quieter now. I am planning on doing the transmission in the next couple of weeks and will take pictures as I go..

Front Diff-about 1 quart

Transfer Case-about 3/4 of a quart

Rear Diff-about 1 1/2 quarts

Here is the TSB

[working4it]

Here is the link to Porsche.com with part list

If you are going to stick with true OEM Differential oil Pelican has it for $57.00 a litre.

Part#000-043-205-30

75w90

http://www.porsche.com/all/media/pdf...SA_KATALOG.pdf

Page 123 and 124

[bigbuzuki]

If you are going to stick with true OEM Differential oil Pelican has it for $57.00 a litre.

Part#000-043-205-30

75w90

www.porscheoemparts.com sells the oil for $34.58 per litre.

[hahnmgh63]

Just ordered up some Redline to do my front & rear diffs since I did the tranfer case a couple of months back. Then it will be time to tackle the ATF & filter for the tranny.

[hahnmgh63]

Ok, got the rear diff replaced (w/redline 75w-90 gear oil), already did the transfer case (Redline D4 ATF), now I just have the transmission and front diff to go. My rear fluid didn't look quite as dirty as Working4itj's did, not sure of his miles, I have (55K on a '06 Turbo S). The consistency of the fluid was good, had a little trransparancy to it, but still was a little blackish. I'm now curious to see how the front looks.

[working4it]

Hahn...I was really surprised how bad my diff oil was. I have 100K on my '04S. Porsche recommends 120K change on the Diff/Trans if I am not mistaken. I am going to do the transmission/filter in the next two weeks and will take pictures as well. BTW how do you like the redline? I have never used it...Used to use Royal Purple but found I like AMSOIL better...

[deilenberger]

Just curious - what is there to "like" about one oil over another?

If it meets manufacturer's spec's (or exceeds them) and does what it's supposed to do - it's just oil. I have submitted engine oil for analysis many times (primarily on motorcycles, but also on cars) - and the results tell me that you almost never experience a failure due to inferior oil. I'm delighted Working4it tracked down that Mobil-1 meets the Esso standards for the ATF.. That's gonna save me mucho $$ when I do a transmission oil change.

[hahnmgh63]

I hate to disagree deilenberger but oil is not just oil. And just because one says it meets a manufacturers specifications doesn't mean that it is equal to anothers. Why not use one that exceeds a manufacturers specifications? What is a manufacturers specifications for? They definitely want their engine to not fail or exceed certain specifications (oil usage, compression loss, etc...) until after the vehicle is off warranty but how much longer, they obviously don't want their vehicles lasting forever. I'm just aaying that a superior oil is one of the cheapest things you can do to protect your rotating components, and what if you increase power output, how do the manufacturers specifications now apply?

As for Redline, I did got to do a tour of the factory 10 years ago when our local Porsche club (WA state) did a tour down to Laguna Seca and was impressed. If you go to almost any manufacturers website you can look at their product data sheets and compare test numbers for the certifications they've tested their oils for. Every oil in the U.S. must be tested to SAE specs but the more more stringent tests are the European tests, ACEA, not all oils sold or manufactured in N. America are tested to this specification or could even come close. Mobil 1 may meet this specification but only in a couple of weights, and just barely where Redline exceeds all of the specifications, especially in the HTHS (High Temp, High Shear) rating, whearas it(Redline 0W-40)exceeds Mobil 1's 0W-40 rating by 28%. Oh yea, Porsche recommmends Mobil One, but not because it is the best, it is a economic recommendation from a oil that just meets the specification from one of the biggest oil manufacturers in the world that gives them a big price break on a big ticket item that must be added to every vehicle they sell. GM recommends it for many of their vehicles, do you think GM is doing it from a economic or engineering decision? VW/Audi, VAG have one of the strictest oil specifications, exceeding those of ACEA, and their minimum HTHS is 3.5, Mobil 1 0W-40 HTHS is 3.6, Redline 0W-40 HTHS is 4.6 which is a better shear rating than even Mobil 1 15W-50, a thick oil. I'll get off my soapbox now, oil is an individuals choice and I'm just saying that it is a cheap insurance not worth saving a few dollars on your oil changes if you are the kind of person who plans on keeping your cars long, even then, why accept extra wear to pass on to the next buyer. My background is Aeronautical Engineering and I can be Anal about somethings, just go to the manufacturers website and check out their product data sheets and compare for yourself, price & availability are all fairly close nowadays.

[SWFLHOMES]

I drained front diff this weekend. Very little fluid drained out! No wonder why it was making noise. The lack of fluid I am sure didn't help my diff problem. I also had to grind 1/4 inch off of my allen wrench to clear the piece that was in the way. I would reccomend doing this MUCH sooner (50 or 60K). I have 120k miles 2004 CS

[working4it]

SWFLHomes- I bet the Diff is much quiter now!

[rifreede]

Thanks for the great information. Put in an order from Amsoil for the transfer case and differential gear fluid. Looking forward to completing this at the end of the week.

[bigbuzuki]

Catch 22 really.

My 2003 CT is still under extended factory warranty until the end of 2012.

Although the Redline products claim to be superior to other manufactures oil specs, the fact remains that they are NOT listed on the Porsche Approval List for oils.

Therefore I won't risk using any oils that don't appear on the list, as I would void my warranty.

Once out of warranty, I will take another look at the status quo.

Edited September 6, 2011 by bigbuzuki

[UTRacerX9]

I hate to disagree deilenberger but oil is not just oil. And just because one says it meets a manufacturers specifications doesn't mean that it is equal to anothers. Why not use one that exceeds a manufacturers specifications? What is a manufacturers specifications for? They definitely want their engine to not fail or exceed certain specifications (oil usage, compression loss, etc...) until after the vehicle is off warranty but how much longer, they obviously don't want their vehicles lasting forever. I'm just aaying that a superior oil is one of the cheapest things you can do to protect your rotating components, and what if you increase power output, how do the manufacturers specifications now apply?

As for Redline, I did got to do a tour of the factory 10 years ago when our local Porsche club (WA state) did a tour down to Laguna Seca and was impressed. If you go to almost any manufacturers website you can look at their product data sheets and compare test numbers for the certifications they've tested their oils for. Every oil in the U.S. must be tested to SAE specs but the more more stringent tests are the European tests, ACEA, not all oils sold or manufactured in N. America are tested to this specification or could even come close. Mobil 1 may meet this specification but only in a couple of weights, and just barely where Redline exceeds all of the specifications, especially in the HTHS (High Temp, High Shear) rating, whearas it(Redline 0W-40)exceeds Mobil 1's 0W-40 rating by 28%. Oh yea, Porsche recommmends Mobil One, but not because it is the best, it is a economic recommendation from a oil that just meets the specification from one of the biggest oil manufacturers in the world that gives them a big price break on a big ticket item that must be added to every vehicle they sell. GM recommends it for many of their vehicles, do you think GM is doing it from a economic or engineering decision? VW/Audi, VAG have one of the strictest oil specifications, exceeding those of ACEA, and their minimum HTHS is 3.5, Mobil 1 0W-40 HTHS is 3.6, Redline 0W-40 HTHS is 4.6 which is a better shear rating than even Mobil 1 15W-50, a thick oil. I'll get off my soapbox now, oil is an individuals choice and I'm just saying that it is a cheap insurance not worth saving a few dollars on your oil changes if you are the kind of person who plans on keeping your cars long, even then, why accept extra wear to pass on to the next buyer. My background is Aeronautical Engineering and I can be Anal about somethings, just go to the manufacturers website and check out their product data sheets and compare for yourself, price & availability are all fairly close nowadays.

Agreed, and well said. One reason that Porsche recommends Mobil 1 is that the Euro blend is actually a full synthetic. The Mobil 1 we can buy here in the states actually isn't a full synthetic, it's made with some Group III oil mixed in (but it sounds like you probably know that already.) They changed it a few years back for the US market. Redline consistently performs better than most oils, it's a great choice for pretty much any fluid need. I'd also recommend AMSoil, though it's a bit harder to come by in most places, and one of the few other true synthetics left.

[hahnmgh63]

UTRacerX9 you said it exactly, Mobil 1 in Europe is a better oil than what they sell in N. America because the ACEA requirements standards are stricter and they wouldn't be able to sell most of the oil that they sell here. It is curious why they call the 0W-40 the "European formular" when it barely meets the ACEA standards and isn't the same as the oil they sell over there.

Workin4it, I do think Amsoil is a good oil, and if you check the product data sheets I just think Redline is slightly better for about the same price. As for Royal Purple, I know many people swear by it but they don't test their oil to the ACEA standard, or at least they didn't as of a couple of years ago so I had nothing to compare it too, who knows, it may be one of the best oils out there but without the right data it is hard to tell, and if you have a vehicle on warranty it would be a mistake to use a oil that isn't tested to meet the minimum standard as I've seen dealers send oil out for analysis.

If you read this months "Excellence" article on oils including the excerpt from LN Engineering on IMS failures that have plagued 911's & Boxsters & Caymans lately you will find some good information on oil. Remember even though we don't have flat tappet engines, the reduction of ZDDP in the N. American market increases the wear on our engines now, but of course our Catalytic converters are going to last another 20~30K. I would rather replace my Catalytic converter than my engine?

[working4it]

Wow...great wealth of knowledge! The mobil rep I spoke to said the Mobil 1 Synthetic ATF is 100% synthetic...

I found this info:

Mobil 1 used to be made primarily with a group IV base stock which is mandatory for any product to be called synthetic in any country except the US. In the US Group III base stock which is made from purified Pertoleum is all that is required to be called a Sythetic, which is what most Castrol Syntec oil is made from (German Made Syntec is the exception as it is made from GIV stock).

Group III base stocks are very good oils. Castrol GTX from 20 years ago used to be made with Group III base stock and it was the best performing "regular" oil available, but that changed when Syntec was introduced (same product and GTX used to be but different bottle)

Some True Group IV Sythetic oils are Redline (GIV and GV), Royal Purple, Amsoil, German Syntec and others. n not stretching the "Synthetic" nomenclature to include GpII/GpIII even though the ISO dewaxing technology & heavy hydrotreating is done. It still produces fabulous base oil.

Mobil 1 Euro formulation 0W-40 is a true GpIV synthetic product

[UTRacerX9]

Wow...great wealth of knowledge! The mobil rep I spoke to said the Mobil 1 Synthetic ATF is 100% synthetic...

I found this info:

Mobil 1 used to be made primarily with a group IV base stock which is mandatory for any product to be called synthetic in any country except the US. In the US Group III base stock which is made from purified Pertoleum is all that is required to be called a Sythetic, which is what most Castrol Syntec oil is made from (German Made Syntec is the exception as it is made from GIV stock).

Group III base stocks are very good oils. Castrol GTX from 20 years ago used to be made with Group III base stock and it was the best performing "regular" oil available, but that changed when Syntec was introduced (same product and GTX used to be but different bottle)

Some True Group IV Sythetic oils are Redline (GIV and GV), Royal Purple, Amsoil, German Syntec and others. n not stretching the "Synthetic" nomenclature to include GpII/GpIII even though the ISO dewaxing technology & heavy hydrotreating is done. It still produces fabulous base oil.

Mobil 1 Euro formulation 0W-40 is a true GpIV synthetic product

That Mobil 1 rep isn't exactly lying, but... :)

Yes, technically any group III oil can be considered synthetic, at least by US standards. However, they does not perform as well as a full synthetic like Redline, AMSoil, or Motul. (From what I've heard, RP is not a true synthetic either, it is like Mobil 1 here.) At any rate, a friend of mine did an OA on RP a few years ago, while it performed adequately for 3k mile use, it did show considerably more wear and viscosity break down than his Redline analysis.

I used to run Mobil 1 exclusively until they changed the formula here, then I switched to Redline. Don't get me wrong, Mobil 1 is still a good oil... but you aren't really getting what you pay for anymore with it.

[deilenberger]

From the Mobil1 FAQ on Bobs the Oil Guy:

http://www.bobistheoilguy.com/mobil-1-qa/

Why does the Canadian PDS for the 0w40 differ from the US version? (flash point is different: 236C for the Canadian one, 230C for the US one, no pour point on the US one, cST at 40 and 100 different..etc).

The Mobil 1 0W-40 is a global product, and it is the same formulation in almost every area of the world. Though we try to maintain complete consistency in the typical properties that are reported for a given product, there are some minor inconsistencies in the values reported in different countries. Note, however, that these inconsistencies do not reflect any differences in the formulation, quality or performance of the product.

Mobil prides itself on having unique relationships with OEM's. What specific advantages does this give you when making Mobil 1? The 600,000-mile Mercedes test is one example. Is Mobil paying these companies to use Mobil 1, or do they choose it based on its performance?

One of the many benefits of having a strong relationship with OEMs is that two-way communication can occur between the engineers who develop Mobil 1 and the engineers who design automotive engines. This ensures that we can develop and test Mobil 1 according to the latest engine technology and specs. In turn, the OEMs stay aware of the capabilities of high-quality engine oils, like Mobil 1, in their engines. Due to confidentiality provisions, we aren't at liberty to discuss our business relationships with OEMs. However, we are confident that the OEMs who rely upon Mobil 1 as a factory-fill believe our product gives their engines the performance and protection it deserves. You don't have to take our word for this – watch some of the videos on our website featuring testimonials from some of our OEM partners, including Porsche.

FWIW..

[deilenberger]

Well worth reading: http://www.bobistheo.../motor-oil-101/

His recommendations for 0W-40 Synthetics (as he calls them "Full Synthetics"):

- Amsoil 0W-40

- Castrol European Formula 0W-30 (a thicker 30 grade oil, almost a 40 grade oil)*

- Mobil One 0W-40

- Penn Ultra Synthetic 5W-40

- Renewable Lubricants Inc. 5W-40*

The discussion on viscosity and what it actually means is particularly interesting.

Edited September 6, 2011 by deilenberger

[deilenberger]

Bob is the Oil Guy on ZDDP: http://www.bobistheoilguy.com/motor-oil-107/Concern: People are worried about the SM oils not having as much ZDDP as the SL and older oils. The reason ZDDP has been used for years is not because of its superior performance but rather its low cost and dual function as an antioxidant. It also has anticorrosive properties.

There are other additives. Some newer oils do not have any ZDDP, and they are excellent products. Just the same, I prefer oils with ZDP for now. The research shows that 0.03 is all that is needed and has the same function as higher levels. The only reason to have more is because your engine is consuming the ZDDP secondary to borderline lubrication from oil alone.

And lastly, too much can be corrosive itself and has shown in some tests to actually increase wear.

[wvicary]

I stick with what the manufacturer recommends as they have tested the product and given it the thumbs up. In the ends it's your vehicle and your money so that makes it your choice to use any oil you want.

Lets not turn this into a debate about which oil is better as the internet is already polluted on this topic. Happy Motoring!!

[hahnmgh63]

I'm not sure who Bob is but some of his advice is contrary to what most auto manufacturers have been saying and even what the SAE says. I would believe much more in a company like LN Engineering who have been building Porsche race engines for years and have been big advocates in better oil to stave off the 996/997 engines IMS failures as well as complaining that the Cayenne's 20K oil changes are a short sighted joke. I also use Blackstone labs for my cars (actually only two of them year round as the track car hasn't been on the track in two years) and they say my TBN's and analysis is one of the best they've seen at 7~8K oil changes but don't recommend to go past 10K on my oil. You can find many examples of Blackstone Oil anaylysis on line to compare yours too as I do on Both Rennlist forum and Audizine to see how the group is doing. I see Bob is the oil guy has a bunch of advertisers inclucing Mobil & Pennzoil so I'm sure you won't see any bad mouthing of those two brands on there. LN Engineering is a Brad Penn dealer (also Swepco, Motul, & Mobil race oils) but speak very highly of Redline in the "Excellence" article. http://www.lnengineering.com/

http://www.lnengineering.com/oil.html

Edited September 7, 2011 by hahnmgh63

[rifreede]

Completed this job today, front and rear with Amsoil Gear Oil and the Transfer Case with ATF. Easy job. Sex 8mm plugs. You do have to take off the shields for the front.