Where is the ATF option Andre? That's what the manual says... (and GB recommended, too )

 

Show-off!

 

I use RedLine 75-90NS and I find that when it's cold, it's not very happy. But once it warms up it works very well. Had Mobil1 in it before and it just wasn't as happy - but you can't beat the availability. I think the Mobil1 would be my 2nd choice.

 

I think this thread is an offshoot of the transmission tech session that was done at Sharktoberfest. Sounds like Redline NS is the choice so far here, I am happy w/ it too...

GB said he uses Mobil 1. He said that Redline usually ends up leaking out of the front seal. Roger & I were discussing after the session that we forgot to ask if that was the ONLY disadvantage of RL oil in his opinion. We could both see that if someone were to pay to have their gearbox rebuilt, and then it started leaking, then that could look bad.

 

I'm the one that asked the question at the tech session curious to see what Greg recommended, but like Andre, I'm also curious to see what others are using. I'm not surprised Greg recommended Mobil 1 and I know Greg knows what he's talking about, BUT I tried Mobil 1 in my transmission not long after I got my GT, no reason to change other than mileage and knowing it was due. My tranny was NOT happy with it and began grinding on shifting. I guess it is possible that the Mobil 1 just showed that my syncros were wearing, but I replaced the Mobil 1 with Redline 75-90NS and it was an amazing transition. As Keith said, shifted like butta...

I was also surprised that Greg mentioned a 15,000 mile change interval for the transmission oil, especially with Mobil 1. My owner's manual says change at 60,000 miles. Greg, is there a reason to change more frequently, or is it more of an issue with higher mileage transmissions?

 

The manual also states 15,000 miles between oil changes.

I cannot speak for Greg but IMO many change intervals in owners manual's are suspect. I could never go 10k - 20k etc... between oil changes with any new car, much less my 928's, I don't care what the manufacture says.

Check out Audi / Mercedes / BMW. I'm not sure when it started but many of their cars do not have a drain / fill port for their transmissions. In the manual they state the factory installed fluid is for the life of the car. I've seen the inside of these transmissions after 100k, it's not working.

There are service bulletins warning owners the dangers of running 17" wheels. Then the GTS got 17" wheels the warning changed to 18" wheels....... Sometimes you have to read through the political and CYA BS manufactures are forced to put out.

Porsche has no problem releasing an oil bulletin stating a modern, low ZDDP oil is just fine for our cars. Engine builders like Greg know better.

 

Pelican is selling it now.

 

Well I found some Kendall 80W90 and used it in the fourth oil change, and it magically got drivable!

Valvoline 75W90, RedLine 75W140 NS (then added Heavy shock 75W250 1Qt), and, Coastal 75W140 (for cleaning out the RL stuff) all failed to make the box behave. Please note the Coastal after it was warm did make it almost drivable.

Also the LSD is now reasonable in the range of can break it by muscling it over.

When I bought the Kendall from the Speed Shop, they asked me how long I have been running Kendall, and this translated into me appearing to know something about gear oils Thanks Greg for teaching me something then allowing me to prove you are correct!

 

In parallel to the engine oil thread that was just revived, I though I would follow up on this. I did not vote, because I don't have enough experience. I had Redline in my box and it shifted ok, but for other reasons, completely unrelated to Redline, I had my box rebuilt by Greg Brown.

I did find that my transmission leaked at 1 seal with Redline. Now all seals are new though following the rebuild, and the box has Mobile 1 in it. Haven't gotten the car back on the road yet. (My SAAB 900 Turbo loves Redline MTL, and I've used it in that car for 20 years. But of course the 928 has a completely different transmission, requirements, etc.)

Now, I am wondering what people are generally using 4 years after this post.

 

Oops, I just put in Swepco 201. I don't know How it performs yet because the car is not running yet. Undriveable? What did it do? Sounds like glue now, instead of oil.

 

This is what is currently in 30. 80 mph on liftbars, with no problems so far....no road test yet....this is supposed to be a direct match for the factory recommended stuff in the manual, but I dunno....

 

I just put Castrol Synthetic 75w90 in and only have 300km since.........hasnt made any difference to shifting and I dont think the PSD likes it but not sure how the oil effects.

The PSD hasnt been serviced.

 

I originally used Redline and it would constantly leak, so bad that I thought i needed a trans overhaul. I changed out what fluid was left and went with the Mobile 1 and if I didn't see it with my own eyes I would not have believed it, it has completely stopped leaking and it runs smooth.

Just my .02

Andy 83 Euro 5-speed

 

Swepco made it almost impossible to shift from 1st to 2nd without nasty grinding noises when cold. I think it's been about 10 years since I tried it, but as I recall, it was so bad that I drained the Swepco out within a week of trying it. Redline was much, much better.

 

swepco for the older non borg warner transmissions helped with shifting with a worn transmission
redline for the S4 trannies. (mix of NS and regular 75-90) why? seems to work well and have never had shifting or grinding issues with trannie over 15 years of racing with it. 10 with the same transmission.