Thanks brutha

 

Ok, but the impact was immediate, I put the car on the lift, dumped the Delvac, filled with the Porsche fill, and then took the car out. I did let it drain for a few hours just to make sure what would drain out did, - no deposits or filings on the magnetic plug. I noticed the difference just backing out of the garage, never mind driving it. The impact was the same the next day in the morning and continues on.

The oil level was correct in both cases, I did the fill both times, and both times I fill, cap, run the driveline while its on the lift to get the oil moving around in the tranny, let it sit for 1/2 hour and then pull the plug and fill again. That last part of the fill is not done with the pump since I find it often will show full but its not, but with a large syringe that can squirt the oil well back into the case (or at leas as well as you can thought that little fill hole. I let that settle and double check that the oil is at the fill hole.

Cheers,

Mike

 

Obviously, the "feel" a transmission is a combination of the mechanics (wear, clearances, etc) and the oil. We appear to have a few examples here so far, and lots of opinions.

Here are oils that seem to have good cold shifting (by the single+ examples we see in this thread). This may be just because this group of oils have additives that make it easier for the syncros to do their job (from very limited opinions)...

• Porsche sourced (999-917-546-00 - $27.89 litre))
• Motul ($28/litre)
• Redline NS ($15.50/litre)

Oils that are more track oriented and may not promote good cold shifting, but perhaps are more track-oriented (from one opinion)

• Delvac ($12/litre)

So far this is all based just on opinions, but heh, I dont' really care since my car shifts better now.

So here is a question: Bill stated that Delvac was not for us street folk, its more of a racing hard-core oil. Can someone provide the evidence that this is true? I am not going to take as gospel that because Porsche uses it in their race cars it's conclusive evidence, oil sponsorship is more than the technical ability of the oil - if two oils are even, it will come to the best deal offered. Perhaps Mobil 1 offered the best deal among their brethen?

On the other hand, what evidence do we have the any of the "cold shifting" oils will not do just a good on the track as the Delvac?

I want to see if we can build enough anecdotal evidence to suggest that Delvac should not be the, as was put before, the "supreme" choice for everyone.

Cheers,

Mike

 

Mike - Sounds like you do a proper fill!

For what it's worth. I've done multiple changes with the same oil: Delvac and Redline NS (before I make any conclusions). I found the opposite of what's been mentioned.

So Delvac for me seems thinner, good for cold starts, tend to grind more/miss shifts (usually shifting into 3rd under wot) when hot at the track.
Redline NS, not as good for cold starts but more consistent and best feel (no miss shifts) when hot at the track.

But this probably doesn't mean much since I also use a small amount of chlorinated paraffin additive...!

 

Mike,

Thanks for posting this.

My coupe had the dealer 60K service a couple of months before I bought it so I haven't changed the transmission fluid yet. It seems a bit thick at cold start similar to your former findings, but when warm has great feel.

My recently acquired C4 cab on the other had has a much easier feel to it w/ 42K miles. I attributed it to different transmission types, but it may be the fluids.

I'll be interested to find out how a Porsche supplied oil might change the coupe's feel.

BTW, if I plug that 999 part number into Pelican's site it comes up as;

"Fuchs Titan Sintopoid 75W-90 is an OEM supplier to Porsche" at $14.25 a liter.

Out of curiosity please, when you do your "top off" fill the second time, approximately how much more oil does it take?

Thank you.

Regards,

.

 

I saw the reference to the Titan oil (did the same search as you), but I am not sure if its identical or not. I also read that the oil I used is actually a Shell product, so who knows ... I wanted to try the Porsche supplied oil, and it was about another $40, so it was a no-brainer for me.

My top off the second time was about 1/8 litre or so - I used a large syringe so it was hard to say, it was a few syringe fulls. The problem is the hole for filling the transmission is right beside a gearset, so when you fill and it's close to the fill hole, its easy to mistake a filled transmission with the run-off from the gear (if you are pumping it in quick) which will also come out the fill hole. I have no evidence, but I also think you can possibly get air pockets, so it will do no harm to cap the tranny, run the car/drivetrain, wait and try again. Like I said, on the second pass I put the oil in quite gently since I want it to settle and not give a misleading measure. I could of relied on the markings on the 1 litre bottles ( I needed 4.3L to do the Turbo) but that would assume the fill of the bottles is exactly right.

I did another fill with this oil on a 96 Targa this weekend, it took about the same to top it up. We followed the same procedure.

Cheers,

Mike

 

Mike, is there a Porsche product sheet available for that oil, maybe one that includes specifications?

Looking at the Mobilube PTX PDF on that thread, at least for that oil it states "High level of wear protection under the most severe conditions". I wonder if there is a reason I should not believe them?

 

Thank you for posting mike. I'll go this route when it's time for me next month.

btw- does the tranny plug have a crush washer?

 

When I got my 993 only the drain plug had a sealing ring. Now both the drain and fill plugs have them; no reason not to.

 

Here is a scan of the Porsche notification on oils. Note the comment about studies that not all oils are applicable, and that they recommend Porsche proprietary oils (of course). Its unclear which oils they have "studied" though.

I tend to go with Porsche recommendations, so below is the notice about recommended oils for most of the transmissions, including the 993. I do have the material data sheets as well, but they contain no performance info.

Essentially two oils are recommended, the Mobilube PTX, and the Shell Transaxle. Sunset does not stock the PTX, they say its only available in 20L containers, so they concentrate on the Shell product, which is what I used.

I do not think a spec sheet of the compositions of the oil is readily available, I have not seen it.

Sorry for the scanning quality, perhaps someone has a better version (George - Geolab?).

cheers,

Mike

 

Yes it does. Similar size to oil plug.

 

I have found that the fill-plug on the transmission typically does not have one - on original cars that all records show have never had a transmission oil change. Cars that have had the oil changed are mixed.

I checked the parts guide - no washer indicated. Most people will put one on "just because", but I do not think its required. (BTW - I do use a washer when I do changes on other peoples cars because, well, its expected.. ).

Cheers,

Mike

 

I think they are all the same....case drain bolt, tank drain bolt, transmission drain and fill bolts.

 

Suncoast has PTX by the liter @ $34ea:


link -> http://www.suncoastparts.com/product...997GT3TRAGT3RS

 

So that is the most expensive so far... interesting on how their web page says "Transmission fluid for most late model manual transmissions, 1999-2012."

That is also a weird looking 1 litre bottle with a handle - it must be 4+ litres?

Cheers

Mike