changed the gear oil in 987.1,a noticable diff!!
 

I now have 11000 kilometers (65k miles) with original gear oil,no problems,but changed it out anyway (porsche states lifetime fluid) well definately noticed a diff,easier and smoother,was surprised.This car is a daily driver,not tracked.I did use porsche stuff.I also bleed out clutch fluid and brake fluid but no change noted on that,clutch felt the same,stil relatively easy to push.Just wanted to note gear oil changing is worth doing.Porsche told ,e not to do it as i am wasting money and will notice no change,wrong!

sorry that was 110,000 kilometers

I went to the Porsche dealer in town here and the parts guy quoted me $48.00 a quart (964ml) for OEM Porsche MT Fluid. I almost swallowed my gum I gasped so hard. :eek:

The service manager happened to be there and he tells me the stuff is made by Royal Dutch Shell in Europe but it is the same stuff, 75W90 GL-5, available from Quaker State in North America, a subsidiary of Shell. He further tells me that although Porsche specified GL-4 when the Boxster first came out years ago, the GL-5 spec today meets all of Porsche's requirements. Something about the sulfur molecules are now compatible with sychros and high pressure differential gears. A little too technical for me but he said they issued a TSB a few years back now specing the new GL-5 formulations.

Anyway, long story short, I thanked the service guy at Porsche but told the parts guy I can't justify $150 on MT Fluid when Quaker State 75W90 GL-5 sells for about $18.00 a quart at most auto supply places and Crappy Tire sometimes has it for less.

So I picked up 3 quarts of Quaker State and I will be changing the fluid on Saturday. I have 74,000 Km (46,000 M) I am doing all fluids over the next few weeks but starting with engine oil and MT.

I'll let you know if I feel any difference in shifting. Currently it is a little 'notchy' when cold but is fine when warm.:cheers:

If you do enough searching about the "lifetime" fluid concept you'll find out what I did. European manufacturers are able to offset the (claimed) total "carbon foot print" of their cars by not calling for petroleum based servicing.

That way they get away with lower gas mileage, dirty pipes, etc. It's pathetic. "Lifetime" means until it gets past warranty.

We have a VW Touareg (cousin to the Cayenne) with automatic transmission. With any other automatic transmission you are an idiot to go more than 30k miles between fluid changes, especially if you tow something (and the Touareg can pull 7700 pounds).

When it started hard shifting between 4 and 5 I did some research and it was the valve body (the other "fixes", mostly software updates are not long term fixes). The guts of the valve body eventually get plugged up with goo and it starts hard shifting, initially in the 4-5 shift.

Dealer? "$8-11K for a transmission please". F that. A company back east sells an updated valve body for $695, exchange. Done.

Now about that fluid. Dealer charges $28/quart and it takes about 2 gallons. I couldn't find anything compatible with the mystery German stuff until I discovered that the transmission is an Aisin (Japanese) contraption. Even that was a bit challenging but eventually I was able to find a Valvoline product that was going to be absolutely compatible. I think it was $30 all up.

Off topic, automatic transmission are a hoot. If you buy a BMW you might have a GM transmission. If you buy a Ford Truck it might have a german ZF transmission (mine did). If you buy a VW it has a japanese transmission. Damn I loathe automatics.

Great info!

Hate to burst your bubble, but the information you were given is somewhat correct, and somewhat incorrect.

The original Porsche gear oil for the five speeds was developed for Porsche by an obscure Royal Dutch Shell division known Burmah, and was designated TAF21. This full synthetic product was developed specifically for Porsche for the Boxster five speeds only, and should not be use in the six speed boxes due to incompatibility with certain alloy components, which would result in premature wear. Porsche actually published a technical bulleting to that effect. Burmah TAF21 never had any type of GL rating as it simply did not fall into any of the GL categories as defined by the API, which is also why other major oil companies never made an equivalent product. The TAF21 product is made exclusively for Porsche in 20 liter drums. The Quaker State GL-5 product is not an equivalent lubricant, which is also why you are experiencing cold shifting issues, a condition where the TAF21 excels over other lubricants in the Boxster.

Don't you just hate it when they specify obscure lubricants?
This link may help?
Castrol TAF-21 (Porsche synthetic transaxle oil) | ATF, Differential, Trans, Brakes, P/S | Bob Is The Oil Guy

There as some things regarding Porsche maintenance I just can't be buggered about with trying to save a few dollars on alternatives - things like genuine water pumps, coolant, alternators and, yes, gearbox fluid.
For heavens sake, if 3 x qts @ $50-00 / qt replaced every 50,000 miles is too much to pay, you're driving the wrong car. Use the search function and you will find threads littered with alternative (cheap) accessories that were changed out AGAIN after the el-cheapo substitutes failed to live up to expectations.
Don't get me wrong, my father was a tight arsed Yorkshireman who watched every penny & I'm of the same mould, but sometimes you just have to pony up and buy the correct bits....

Gear oil
 

JFP what gear oil do you use in the six speed manual transmissions?

Not really, because the Castrol TAF-X product, which is a GL-4 gear oil also sold under their "SynTorq" brand in Europe is a different product developed to address the poor low temperature shifting properties of GM and Chrysler products, and which is available in the US exclusively under GM & Chrysler product part numbers. While it is an interesting low temperature gear oil, completely water-white in appearance, and is also used widely in Nissan products, the Castrol TAF-X carries the API GL-4 rating which means it is still different than the Porsche oil which does not fit in any GL category. Even Mobil 1 once commented that the Porsche five speed gear oil was so unique and represented such a small market segment, that they had nothing even close to matching it and would not be developing anything suitable.

We get ours in drums from Porsche; we use the Burmah product in the five speeds, a Shell product in the six speeds under Porsche part number 000-043-204-19, and for the gearbox section on the PDK we use Mobilube PTX (Formula A) under part number 000-043-204-20.

I have to agree with you on this. Just about everyday, we get someone in, or read about it online, that is trying to go as cheap as possible on these cars. People are always looking for a free iPhone app as good as a PIWIS, or a $7 off the shelf bearing to replace the IMS (which really makes me cringe). While we try to politely explain the differences between various products, unfortunately some people's hearing seems to shut down as soon as price is mentioned. If you want to go cheap, get a Honda or a Toyota Camry, but don't do it to one of these cars. The truly funny part is the guys driving the 2015 Porsche Turbo S or a Ferrari 458 Italia are always asking, "Is there something better?", never something cheaper.

Buy the 75W90 Porsche Gear Oil from places like Sunset Porsche or Suncoast Porsche. It's about $39/litre. You need 3.

This is not a lifetime fluid. I think the Porsche interval is 100,000 miles. I always do it a 50K and get a Blackstone UOA done for data.

This should have been your first clue that your gear oil selection was not the best.

Jeff. I just bought 3 litres of 999.917.546.00. Is this the correct part no for a 2000 5 spd transmission and if not, is there a litre spec for the correct oil.

Thanks.

No, that is a six speed oil. The Burmah product for the five speed (N 052 911 C0) in a 20 liter drum. I do not know what part number they put on it in one liter containers.

Do you know of a source where I can buy litres of the correct oil?

You need to contact dealers as only some of them repackage it into liter bottles. Try giving Sunset Porsche in OR a call, they used to do it, but I do not know if they still do.

Well, in viewing Porsche Tech Info 3401 (4/99), the following statement exists:

Note: Burmah (TAF 21) part number N 052 911 C0 is not approved for use in Boxster S manual
transmissions.

I can't read this the same as "use only Burmah oil" for non-S

The document instead I think fairly clearly indicates the Shell and Mobil products can be used in both cars.

Is there a later document that clarifies or indicates different?

I Guess there is a little confusion. My car is a 2003 S , 6 speed. The dealer service manager did mention the 5 speed fluid is different and that they only have it in drums and don't sell it in Quart containers. The stuff they do sell for 6 speeds is the 75w-90 GL-5 made by, he says, Shell in Europe. He said the Shell, Quaker State, Pennzoil or Mobil 1 GL-5 are all fine in the 6 speed. The stuff currently in my car is Porsche OEM that is the original oil I believe and it is a little notchy in 2 gear when cold. Fine when warm

Anyway thanks for the input. I haven't yet done the change but hopefully I get to it next weekend. The IMS Guardian install took longer than I thought. And I really need to drive on such a gorgeous day so MT fluid change took a back seat.