notbostrom

75-90NS ns = no shock i beleive

BobbyT

Pete Lech/RallyJon: As a data point, my 993 has LSD and I've had zero chatter since installing the Redline 75w-90NS. Redline did mention when I ordered the gear oil that they had friction modifiers available which could be added if needed.

quasr

Wow, based on this posting, today I had my transmission oil drained and the Redline 75W-90NS installed. I did not have any of the friction modifier additive installed. Just 100% NS. I will have to say I noticed a difference within one mile of the shop. Each gear was much smoother to access and downshifting was noticeably better. I have previously run Mobil and Redline MTL but neither came close to the smoothness I now have.

Just one more example of how I have made my 993 better based on informative postings. Thanks again!

bluejam

Sure is comforting to hear others with the same issue. I also have the 1st to 2nd grind when cold. I will change my gear oil soon with the Redline.

How often should gear oil be changed? ("normal" driving)

quasr

Seems like I remember it being changed during the routine 60k maintenance. Not sure though.

ABCar

For those of you with slight notch and grind when shifting I thought I would post my own journey starting with my transmission oil change one month ago using Royal Purple 75 90. Previously, the trans was a bit stiff when cold and tolerable when warm but thought I would upgrade to RP oil which I have used on and off in various cars for years. Since the change, I feel like I have no syncros...this oil is not right for the 993 with LSD.
Today I am going to get the redline 75 90 NS as described in this thread. Update later today. *My mechanic here told me he uses the RL oil but at that time we did not discuss the NS issue since I hadnt researched here yet. If he has no NS I am going TRex.

Cactus

I always have to be deliberate with my shifts because sometimes it gets hung up and doesn't go in almost like it gets caught on something. Changed the fluid last year and used what was in it....Mobil 1 Delvac with no improvement. Might try the Redline since it is easy to change.

cgfen

whew, just saw your post and was reading with a bit of trepidation since my box exhibits the same behavior.
~ 4 weeks ago i bought 4 qts of Redline 75W-90NS that will be going into the car as soon as i have the chance.

cheers

Craig

DanQ

NS=Non slip per
https://www.pegasusautoracing.com/gr...roupID=REDGEAR

VMXWinn

+2 On the Redline. I was having the same issues with the 1st to 2nd and 2nd to 3rd (to a lesser degree) when the gearbox was cold and would almost go away when warm. Changed to the Redline NS and it all went away. Nice shifting cold or hot. SOLD!!!!

Augustus Davies

my '95 has 50k miles and exhibits the same problems, switched to Swepco and saw some improvement, especially when the box is warm...but not much...

a buddy of mine has a '95 with 90k miles no trans work ever, he runs Swepco and his car shifts buttery smooth..up and down...wtf...

...would have tried Redline before but was advised against it from a Porsche mechanic who also builds Porsche race cars...said Redline creates a yellow powder on the gears and shafts etc...making it a real bitch to clean during a re-build...any comments?....Steve Wienier??..

cgfen

Just in case Steve misses this, he told me this when i asked him the same question, "Hey Craig,

We use Mobil 1 Delvac in our G50's and sometimes Redline. No Swepco for these things!

Make certain that the clutch is releasing properly; flush the brake hydraulics to fix this."

There may be more to his clutch release suggestion than many of us realize.

Cheers

Craig

ABCar

Drum roll pleeeeaase...........................

RedLine 75-90 NS restored my transmission action to perfect!

SuperUser

cool

Deadeye

Did not work in my box. I guess it's time for new synchros