zschicago

I just bought my 993 about 3 weeks ago. Was getting a little grind when downshifting between 3rd & 2nd. After reading a lot on Rennlist about guys using Redline 75W80NS, thought I would give it a try. I was shocked on how nasty black the oil was when I drained it. Put in the new stuff and immediately noticed a improvement. No more grind. Awesome..

Kiwi Carguy

Great to hear the improvement. I had my shop change the oil when I got the car as I was experiencing what felt like worn syncro's. I'm pretty sure they put in Pennzoil and it was a bit better but not enough.

So I'm thinking of trying either the Mobil Delvac that has been recommended on here and the 964 & 964T board however now I am leaning more towards the Redline. The thing that concerns me is the recent thread about the Redline and the fact that it doesn't have friction modifiers? Are these necessary in a box with a LSD.

Basically I don't want to improve the shift only to screw my LSD?

Any input from the techy guys would be much appreciated.

Thread referred to above here https://rennlist.com/forums/993-foru...ng-solved.html

ABCar

I bought my car with old tranny oil. The dealer mechanic recommended Royal Purple 75-90. My Car shifted very notchy...worse than with the old oil!
Switched to Redline 75-90 NS two days ago. Feels like butter and now a true joy to shift in all directions.
Make sure you go with the NS variety...which is different than the non NS. It has to do with the presence (or absence?) of additives that adjust viscosity at different temps, bottom line is that it is the correct 993 T-Oil. My Porsche mechanic (who also races) said it would be okay with LSD but maybe others in the know have another opinion.


Glad to hear we are both having the same good experience ZS.
Also, OT, do you ever make it to Gingerman or West Michigan?

jaholmes

I had a tough time finding the right oil. I tried the Delvec stuff but it was way to slippery. I ended up going to the dealer to get the Porsche stuff. I think my 97 had the original mystery fill from the factory. It's good to know redline works.

1pcarnut

Good to know, thanks. Went by the local NAPA store today and they can get it for me so this sounds worth trying.

zschicago

I have a LSD. I called Redline and two Porsche shops in Los Angeles. All recommend Redline NS for the 993 with or without LSD. I ended up getting it from Carquest. They had it at their warehouse and was able to get it the same day. I was surprised.

mongrelcat

The Redline tech sheet says for use with some types of LSDs. They have an additive available if one encounters too much lockup.

http://www.redlineoil.com/product.aspx?pid=47&pcid=7
http://www.redlineoil.com/content/fi...uct%20Data.pdf
@ABCar, thanks for bumping that other thread. I would have gone with Delvac (like you I've discovered that Royal Purple is not the answer) but I'll be trying this stuff shortly instead.

911RufRT

I am about to try Motul's Gear 300 tranny fluid. Has anyone here tried it in their 993?

Peter B

+1 on the Redline.
Seems to have taken the slight graunch of the 1 - 2 change when the engine was cold and generally the gearshift up or down is noticeably lighter. A clutch release fluid flush also improved matters and the foul liquid that was pumped out was almost as black as the tranny oil that had been in for the last 30,000 miles. Luckily no swarf in there!

matt777

Interesting topic as Delvac was the right stuff here not too long ago. I had Redline in last year because it was in stock at the local speed shop 1 block away from my office. Last fall I went to great expense to get Delvac when I changed my clutch out. Its only available in 20 litre pails in Canada. I can't say there was a great difference in performance and I'll lump the Amsoil Extreme Duty in that group too which I ran the year before. IIRC the Amsoil might have been the best of the lot but I only noticed differences when the box was cold. With any of the oils the 1/2 shift is not smooth for the first few shifts and it helps to shift into neutral first.

Bill Verburg

Delvac is and has been the factory fill for all the Cup cars for a long time, It sure works well in mine

from the 2009 Cup manual
"The use of Mobil ‘Mobilube’ SHC gearbox
oil is recommended."

SHC was renamed Delvac a few years ago.

that said I'm sure that there are a lot of good gearbox oils out there

chris walrod

I would agree with Bill that Delvac is the way to go with gbx's with steel syncro's -- I havent tried it with std syncros as of yet -- just the normal M1 off the shelf.

Redline works well in late model Porsches as well as Ferrari's.

Havent tried Motul -- but have had bad luck with Swepco 201 (PO fill), and rightly so as its best used in 1986 and before 915's.

Stealth 993

Not that Redline isn't a AWESOME product. But if the fluid is old, & crap, anything will be a improvement! In the BMW world, people swear by it, some were going to replace a trans, then after putting in MTL, they didn't need to. It's supposed to be changed out every 2 years, but I bet most have very old fluid in there.

I have had no problems with any Redline product, my on track experience has shown lower temps with it. I also use Amsoil in my cars, with great results!

AOW162435

I change my tranny fluid each Winter and have used Mobil1 75/90 SHC (Delvac) each time. The transmission shifts great and I have ABD/Limited Slip.

Brian Copans, who knows a little about these transmissions, recommends Delvac as well...


Andreas

e9stibi

Have Mobil Delvac but still some notchiness. Will go Redline next time.