Redline in a 6-speed for cold morning shifting, "test" results

[saaber]

Have used redline in other cars and it has made a vast improvement so I tried it in the Boxster 6 speed (73k miles) to improve cold morning shifts.

1) 75% redline 75W90NS, 25% stock fluid (not 100% because I pumped and filled via fill hole to save time) - Cold shifting improved immediately, notchiness in all gears increased

2) 90% redline 75W90NS, 10% stock - better cold shifts, more notchy all gears

3) 60% redline 75W90NS, 40% redline MTL (70W80) - about the same, maybe a bit more notchy

at this point I was very uncomfortable with the notchy shifting so I went back to 100% stock fluid

4) 100% stock. Surprisingly, cold shifting is excellent. Am very happy with lack of notchiness in all gears.

Conclusion: For this particular car, the stock fluid was much, much better than redline. So if you have cold shift stiffness on a 6-speed, I would recommend changing out the fluid and refilling with the stock fluid. It worked very well on this car anyway but I know others have had very good results with redline.

[schwank]

Thanks for your experience. We see the notchiness in 2nd and 3rd on cold mornings.

My indy doesn't like to change fluid so I am thinking of doing it on my own.

Where are you at in Oregon? We certainly had a chance to test in the cold today! Heck I got to test the limits of traction on my way to the office this morning!

[saaber]

Originally Posted by schwank

Thanks for your experience. We see the notchiness in 2nd and 3rd on cold mornings.

My indy doesn't like to change fluid so I am thinking of doing it on my own.

I see you are in Portland. Ever use A and P specialties? I have never used them but I hear they are the ones to go to.? Marque Motors I have found is no cheaper than the dealer, but I hear they are knowledgeable as well. You don't want to know what Sunset Imports charges for a tranny fluid change ha ha but Justin there really knows his stuff I think. He suggested maybe upgrading to the newest 911 shifter which is awful tempting. Apparently it shortens the throw a little and it is more precise. I wasn't sure if he was talking about the plastic portion that the shifter goes into only or the whole shifter.

[HammerESQ]

Thanks for adding to the discussion. I have been researching changing the fluid in mine to solve a notchy 1st to 2nd on a cold morning. What was the stock fluid? Mobil 1 or something I need to pickup at the dealer?

Thanks,
Eric

[saaber]

Originally Posted by HammerESQ

What was the stock fluid? Mobil 1 or something I need to pickup at the dealer?

The part number on my receipt says:

4 000-043-304-71-SP TRANS OIL

So with a bit of research you can probably find a source for it (I couldn't and just had dealer change it). Here is another place to look...

via tholyoak on this forum:

"999 917 546 00 Shell (Transaxle) - 1 liter container

Check out renntech for more details

http://www.renntech.org/forums/index.php?showtopic=7060
__________________
1999 Boxster 3.6X51 Ruf 3600 Clone
1984 944 Original Owner"

Saaber, good post.