Bruce In Philly

Great stuff Luke, thanx.

So....... I always had a tough time getting into first gear 2009 C2S and found I can lessen the problem by changing how I shift: Make a pronounced "L" in straight lines. Move straight to the left until you bang firmly into the reverse stop, then striaght up forward into first. (I discovered this after I put in the Numeric shifter and found that adjusting cables or the shifter should have no effect on gear jamming).

I see that Mobilube is less viscous than Delvac at freezing temp.... is this good or bad for shifting smoothly into first?

Peace
Bruce in Philly

GTgears

Synchros absolutely require friction to act. Think about it. Their primary function is to slow down or speed up the idler gear so that it is moving the same speed as the shift sleeve. When you pull the handle, the shift fork moves the shift sleeve towards the gear. The synchro pinches down on what is called the cone, altering the speed of the gear. If you had no friction, there would be no bite and the speed wouldn't change.

Now here's where it gets interesting... In my experience, Redline is too slippery. Even though the blurb on the NS oil says that it has no friction modifiers, their formulation is still just too slick and doesn't provide enough friction. For a street car, I consider Delvac too far to the other side.

There are detailed threads discussing this in other subforums, but the quick and dirty answer is the difference between Delvac and PTX is friction modifiers. The beauty of friction modifiers on a street car is they help keep your car shifting smoothly first thing in the morning before things are warmed up. Friction changes with temp, right? You put Delvac in and it will have balky shifting for the first ten or 15 minutes. We use it on the racecars all the time because it has great high temp performance and it is relatively cheap. But for a street only car? I tell guys stick with the PTX, especially if you drive the car year round and deal with morning ambient temps that are ever 50 degrees or less. You will enjoy your car more and your synchros will last longer because of the presence of those friction modifiers. And as was mentioned, you can get it from Suncoast if your dealer is too damn cheap to keep a drum on hand.

GL4, GL5, GL4.5? There's a rating system for transmissions, ring and pinions, and transaxles. If you had a BMW or Mustang you would have a transmission with gears and then a drive shaft to your rear end where your ring and pinion would reside in the rear differential. You have a transaxle, which has the two combined into one unit. This provides interesting lubrication needs. GL4 is for a transmission. GL5 is for a ring and pinion differential assembly. Traditionally, oils serve one well or the other well. GL5 oils often don't shift well or contain additives that are no good for the yellow metals that are part of synchros. GL4 isn't robust enough for a rear end and the stresses that ring and pinion gears see. GL4.5 is a hybrid oil, for lack of a better term. It is intended to protect your ring and pinion AND give you good shift performance and durability for your synchros.

cvtbenhogan

Luxter

Motul spec gear 300 for the 997. See below


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Category : Cars
Make : Porsche
Model : 911, 997 (2004 - 2012)
Type : 911 Carrera (2004 - 2008)




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ENGINE M 96/05

DIFFERENTIAL, FROM AUTOMATIC

TRANSAXLE, MANUAL 6/1

Capacity : Capacity 2,6 litre Service fill
: Capacity 2,9 litre Dry fill

Use : Normal
Intervals : Change 180000 km / 120 months
Products : GEAR 300 75W-90 (year-round)


TRANSMISSION, AUTOMATIC TIPTRONIC S 5/1

HYDRAULIC BRAKE/CLUTCH SYSTEM

POWER STEERING

CAVU

I've had fairly quick response from RedLine. Just drop them an email with your question and see what they come back with. Looks like you need to target the NS version http://www.redlineoil.com/product.aspx?product=58304

In my case, I needed to change out the transfer case fluid in my G500. They helped me from making a mistake. It seems GL5 has some additives that are hard on the G500's brass synchros.

Luxter

Yes, I saw your past posts about Gear 300.
All I can say that Motul was NOT recommending Gear 300 at the time I compiled all information in my thread. See attached screen shot.
I noticed they changed their minds since.
What can I say ?

Worth noting is that the data sheet for Gear 300 has not changed during that period.
Must be marketing then .......

I also totally agree with GTgears comments above. Very sound advice.

Luxter

Porsche require kV to be under 600 cSt at 0*C. So I this case it's good for smooth shifting in cold.

Cheers,
=L=

Spiffyjiff

FWIW, a well respected indy near me (race winners and TRACK TESTERS of most everything they do/sell) advised me years ago that some of the biggest race teams pour $$$'s into analysis only to come up with pretty much the same formula as: redline 75W90 + 75W90ns in a 50/50 ratio. i've been using it for years, 30k+ miles, and 75 track days. smooth as silk, no issues whatsoever, and no abnormal test results from blackstone.

yvesvidal

If you had tried to buy the oil yourself, the Porsche Dealers will usually give you 3 to 4 liters of the original Porsche gear oil. You could have then brought it to your indy.

The smell of the gear oil is extremely foul and disgusting. Make sure you do not spill it.

Yves

Luxter

Would you care to elaborate on the Redline 50/50 mix? I'm trying to understand why a mix is required and why these two specifically.

Didn't Redline get it right in first place, or compromised somewhere along the way?

Cheers,
=L=

Spiffyjiff

i have no idea the logic behind it, only that i trust the knowledge and experience of my race shop. maybe it's like the mobil 1 kool aid porsche serves - yes porsche recommends (read: marketing agreements ) it but by no means is it the best out there. the mix above is probably "better" than OEM, etc.

Lvt19672

So you mix 1.5 quarts of redline 75w-90 with 1.5 quarts of redline 75w-90ns when you change your transmission fluid? I'm due for a tranny fluid change and was going to go with the Porsche branded stuff but this redline concoction has me interested.

lurchphil

The Mobilube PTX is absolutely the best bet for a dd. Shell makes a very similar product that is bottled by Porsche. The manual for my 2012 911S specifies the Mobilube PTX. You made the correct choice! I tried the Motul 300 75w90 in my 2008 911S. It was okay but not as good for shifting performance as the Mobilube PTX.

Carmichael

Anyone use Royal Purple MaxGear 75W90?

I used it on my last car when I installed a Quaife diff in the transaxle. I originally filled it with Redline MTL and the shifting action worsened, and the diff began to chatter. BMW/MINI specified ATF as the factory fill. MTL was supposed to be the best fit for the transaxle.

I switched to MaxGear and it improved shift feel and quieted the diff down. It was even better below freezing.

Here's the data sheet: http://www.royalpurpleconsumer.com/w...S_Max_Gear.pdf

Pretty useless to have viscosity values at -65*C, though ...

Bruce In Philly

Update: My indy charged me about $90 in labor to change the trans oil. I supplied the Mobilube from Suncoast at $113 for three liters including shipping.

DIY is the way to go. I keep threatening to buy a lift.... I think I paid for one many times over now.

Peace
Bruce in Philly

Wasserkühlung

I just changed mine with redline as my car is at 115k miles. The previous owner must have changed it before me (no way to tell without pulling plug) The gear oil that came out was very clean (just changed recently) I am not sure what fluid came out but after installing the redline my cold shifting got a little better. This is a easy DIY job with a fluid exchanger. Get the trans hot and pull the plug, let drain for about an hour, pump 3 liters fluid in until it starts to overflow, cap it and your done! Oh and I have the benefit of using a lift. Not worth it to do this job on the ground. Used gear oil smells worse than dirty diapers