Planet-9 Porsche Forum banner
21 - 40 of 40 Posts

·
Premium Member
Joined
·
1,847 Posts
Curious as to why you or others believe the the transaxle oil is in need of change? How are you making that determination?
I could have sworn I've answered this before, but what the heck, a moderator is asking. :)

The transaxle has that special combination of metal-to-metal shearing action, high heat, and no filtering. While the differential gears are pretty resistant to wear from particles of metal in the lubricant, the synchronizers, often being softer metals, like really clean lubricant. When I've changed the oil in manual transmissions and some differentials (mostly LSDs, to be honest) I could see a sheen of metal particles floating in the oil in the sun. I've also found over the years that manual transmissions that have had their fluid changed regularly (which, to me, is about every 20K miles) shift better and more consistently over time without a rebuild. This is subjective, but I'm paying. ;)

Transaxles generate more heat in a given package than separate transmissions and differentials, and in the Cayman the transaxle is tightly packaged with the engine, further putting heat stress on the transaxle assembly. An LSD would make it worse, because the discs shed particles as they wear. If you add all of this up it seems to me that a gear oil change is cheap insurance for those that plan to be long-term owners, as I do. If I planned to keep the car only 3-4 years I wouldn't bother at all.

I'll also 'fess up to being very cynical about manufacturers' maintenance intervals, perhaps overly so. I understand the data and some of the science, but while a car may run okay with very long maintenance intervals, I find they often run tangibly better with shorter intervals, and I'm willing to pay for it. I want a car like-new in 7 years, not a 7-year-old car, if that makes any sense. On the other hand, if someone wants to follow the manufacturer's recommendations to the letter I'll seldom be the one dissing them.
 

·
Registered
Joined
·
1,767 Posts
You'll need four quarts of 75W-90 oil, but you'll only use about 3.4 quarts, and I highly recommend Redline 75W-90NS, if you have a stock or Quaife differential.
Can you tell me why you prefer the Redline oil over Castrol and Mobil products?
 

·
Premium Member
Joined
·
1,847 Posts
Can you tell me why you prefer the Redline oil over Castrol and Mobil products?
Redline will tell you specifically what the base stocks they use are. The other brands won't, especially Mobil-1, which has been very cagey the past few years about just how synthetic their lubricants really are. What the heck is "tri-synthetic" anyway? Castrol, Royal Purple, Mobil, Chevron, Shell, Total, Quaker - and most other brands try to be mysterious. Amsoil and Redline are the only two brands I'm aware of that talk the talk. I like transparency.

I don't like Castrol as a brand, in general, because these were the folks that originally began calling hydrocracked petroleum-based oil, the so-called Group III oils, "full synthetic" oil in the US, and fought for the right in court. Shame on them, Group III oils are petroleum, and I won't knowingly buy any Castrol products for that reason, even if they're of equal quality.

Unless you have a friction-disc-based LSD it is not a good idea to have friction-modifier in your gear lube. It compromises the lube qualities, and for transaxles it is none-too-good for synchronizers. Redline lets you buy their gear lubes with and without friction modifiers (the gear lubes without it have the "NS" designation). Other brands don't give you this flexibility.

Over the years Redline has had very consistent quality and a huge range of products. Other brands may be as good, but I've gravitated towards Redline out of long-term trust.

(FWIW, Amsoil is pretty good stuff too, though their marketing leaves a lot to be desired.)

All of this said, I doubt you can really go wrong sticking with Porsche's recommended lubricants. I just happen to have other preferences. It's not like I rushed to get the M1 out of my motor after delivery. :)
 

·
Registered
Joined
·
151 Posts
Changed the transaxle fluid today with 2,992 miles on my '08 Cayman S, using the excellent instructions from Blueone earlier in this thread. Took a little over two hours working carefully, doing exactly what he said. Used exactly three quarts of Mobil Delvac 75W90 Synthetic Gear Lubricant (supposedly factory fill) plus about 1 1/2 50 gram tubes of Lubro Moly MoS2. Got a mid-drain sample of the factory-fill lube to send into Blackstone Labs for analysis, will post results here once they come back. Pretty easy to do, no leftover parts, no leaks, no breaking down on the side of the road afterward. Total cost about $70, don't know what the dealer would charge but it would be More. Thanks Blueone & all for the good advice! Dave
 

·
Registered
Joined
·
6 Posts
Cayman Manual Transmission Gear Lube change

Hi changing the Tranny Oil on my MY07 Cayman with 10k miles. Thinking of using Amsoil Severe Gear 75w 90 GL5. Does anyone have any info on doing this or maybe where I can find a DIY write up? Interested in Torque Specs, Fluid quanty, if the cross-brace has to be removed etc etc..

Thanks
 

·
Registered
Joined
·
40 Posts
If all you're doing is changing the tranny oil, you can save a lot of time by making a 2" hole through the reinforcement plate under the drain plug. I used a hole saw, with the hole's center located about 3/4" left and 1/4" forward of the drain hole in the plate (basically, I just enlarged the drain hole). With a little care, there's plenty of room between the plate and the tranny to clear the center bit of the hole saw. Once you have access to the drain plug, everything can be done without any further disassembly or modification.
Are there any Pics or Diagrams out there on this mod?

Regards,

~Gary
 

·
Registered
Joined
·
61 Posts
dbyker,

where did you get the 30 ft/lb torque spec for the plate from? In my old Boxster service manual that I still use as a reference for my Cayman S I found 48 for the nuts and 34 for the bolts. Suggestions anyone??
 

·
Registered
Joined
·
31 Posts
I've RTFF and no where can I find clear information on any special tools/sockets necessary to do this basic service. I have a 2011 Spyder. I have a massive tool box but don't have the following tools/sockets mentioned in some of the threads I've read. Unclear what models these apply to, never clear. Any help on this question?

16 mm triple square on one side and 17 mm hex
12 point spline with a 16mm o.d,. tamper proof with a hollow center.
 

·
Registered
Joined
·
31 Posts
how often should you chance the gear and or transmission oil?
My 2011 Sypder at ~21,000 miles is on its third fresh trans oil. What it came with, the one the prior owner did at 12,500 miles and the one I did at ~20,000. The car has seen a number of track sessions. I was very happy to have replaced the fluid. I don't know or care what the factory service interval is. When I drained it, it looked dirty (doesn't it all) and was glad to get new Redline trans fluid in there. $70, an overnight drain, done. Was it necessary for peace of mind? YES. Was it technically needed? hmm, Blackstone Labs said "...no issues", but here's the enitre "comments" section...:

"The only element that's out of line in your Spyder's tranny sample is iron, which comes from steel parts. Of course, the extreme conditions at the track are probably factors, and transmissions that see that
type of hard use often don't wear like universal averages, so we look for them to produce steady wear levels
from sample to sample. Some excess iron may turn out to be the norm for your engine(sic); we'll know more as
trends build. Otherwise, everything here looks good, and we don't see any issues. Averages are based on
~15,700 miles on the oil."


And note that my fluid had ~8,500 miles on it, far less than the "average" sample they report on at "15,700 miles on the oil". In conclusion, I'm ok with $70 to help protect and prolong a very expensive transmission.

fwiw, if anyone here wants to swap .pdf files of their Blackstone tranny oil reports for comparison, please pm me and I'll send the complete Oil Report with all the numbers.
 

·
Registered
Joined
·
105 Posts
thanks for the reply, should this apply even on non tracked vehicles? neither I nor previous owner ever tracked the car, I'm in 46k miles, with no history of tranny/gear oil changes yet... is my drivetrain about to blow up?
 

·
Premium Member
Joined
·
2,528 Posts
thanks for the reply, should this apply even on non tracked vehicles? neither I nor previous owner ever tracked the car, I'm in 46k miles, with no history of tranny/gear oil changes yet... is my drivetrain about to blow up?
Probably not. If you're worried for some reason change it and send a sample off to Blackstone. For normal street driving you'll likely be fine with the factory recommendations. That's not to say that changing more often will hurt anything and may add a bit of safety margin. With harder use, track for instance, changing more often is a good idea and is also typically recommended by the factory. I don't recall what the recommended interval is offhand but it is rather long. You should be able to find this in the warranty/maintenance book that should have come with the car or in P9's Files section if the manuals didn't come with the car.
 
21 - 40 of 40 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top