manual gear oil suggestions?

[Flavor 987S]

Originally Posted by 986FortyEight

There has been a lot of postings on oil and some are pretty comprehensive. I remember reading a great one by Charles Navarro on why he does not recommend oil but if you go to LN engineering's site you will see what they think is good enough to distribute.
I replaced mine recently with Royal Purple and ran TTs, AXs and DEs without any noticeable difference. (I'll try Motul next).
For the DIY, Bentley's is your best help. Not too bad of a job (Except measuring the oil level).

What???

Jhandy is asking about manual gear oil....not engine oil. And yes, Charles clearly recommends specific oils on his web site. Did you read his entire "Freq. Asked Questions" link? Excellent reading. You will see that he recommends specific oils, and recommends oils to shy away from (like Mobil 1).

[cnavarro]

The OEM fill on race cars from the factory used to be (and might still be) Mobil 1 SHC, which was rebranded under their industrial lube name Delvac 1. We've used it for years, when it was only available in 55 gallon drums. I used to even bottle it for customers, until Mobil started offering it in gallon jugs. It's different from the M1 gear lube found at Autozone, etc., and I've used and recommended it for years.

[JFP in PA]

Originally Posted by cnavarro

The OEM fill on race cars from the factory used to be (and might still be) Mobil 1 SHC, which was rebranded under their industrial lube name Delvac 1. We've used it for years, when it was only available in 55 gallon drums. I used to even bottle it for customers, until Mobil started offering it in gallon jugs. It's different from the M1 gear lube found at Autozone, etc., and I've used and recommended it for years.

Charles, an interesting response, particularly in light of the fact I had read the same explanation elsewhere and asked our Mobil rep about it some time ago, got a totally confusing answer and then was referred to their “technical group” who responded, “Mobil no longer produces a suitable gear oil for the Porsche transmission. You should consider contacting a Porsche dealer for an appropriate replacement.”

Any thoughts?

[cnavarro]

I would file that response under the cookie cutter answer. If I ask my Mobil rep, they wouldn't know what a Porsche was :-) - just a bit of an exaggeration, but you get the point.


Since the gearbox is sourced from VW/Audi, it would take the same fill and their lube may be a fully-synthetic GL-4 rated gear oil. There are VERY few true GL-4 oils available, most out there are GL-5 rated (which is supposed to be backwards compatible).

The tip's differential on the other hand calls out specifically for a GL-5.

Technically, any 75w90 or 90WT GL5-rated gear lube should meet the requirements for the gearbox IMHO.

It's best to google about vw/audi gearboxes rather than Porsche ones, since you'll find a lot more information and discussions about the vw/audi counterparts to the Porsche ones.

[JFP in PA]

Originally Posted by cnavarro

I would file that response under the cookie cutter answer. If I ask my Mobil rep, they wouldn't know what a Porsche was :-) - just a bit of an exaggeration, but you get the point.


Since the gearbox is sourced from VW/Audi, it would take the same fill and their lube may be a fully-synthetic GL-4 rated gear oil. There are VERY few true GL-4 oils available, most out there are GL-5 rated (which is supposed to be backwards compatible).

The tip's differential on the other hand calls out specifically for a GL-5.

Technically, any 75w90 or 90WT GL5-rated gear lube should meet the requirements for the gearbox IMHO.

It's best to google about vw/audi gearboxes rather than Porsche ones, since you'll find a lot more information and discussions about the vw/audi counterparts to the Porsche ones.

I have less respect for Mobil 1 everyday............

Just for informational purposes, Red Line continues to offer a good selection of GL-4 full synthetic gear oils. Reason I know this is that Nissan continues to require GL-4 gear lubes and the syncros (and some bearings) they use don't seem to last very long with GL-5 oils. We've used the Red Line GL-4's in our client's Nissans with great results.

For what it is worth, under the API specs, the additives’ that make a gear oil a GL-5 should make the oil incompatible with a GL-4 gear box. I know some oil companies have claimed to have oils that can be used in either one, but having seen what a GL-5 oil does to the internals of a GL-4 Nissan gear box, I really wouldn’t trust the claim that a GL-5 is always backwards compatible………….

[941MXVET]

Originally Posted by JFP in PA

I have less respect for Mobil 1 everyday............

I saw this on another site, you may be interested:


https://www.mobiloil.com/USA-English/MotorOil/Car_Care/AskMobil/Group_3_Base_Oils.aspx

[JFP in PA]

Originally Posted by 941MXVET

I saw this on another site, you may be interested:


https://www.mobiloil.com/USA-English/MotorOil/Car_Care/AskMobil/Group_3_Base_Oils.aspx

Not exactly "news", they have been doing this ever since Exxon acquired Mobil in December of 1998, which is why the performance of their oils has deteriorated so much since the acquisition, and why some grades no longer carry ACEA ratings……..

[tnoice]

Originally Posted by 941MXVET

I saw this on another site, you may be interested:


https://www.mobiloil.com/USA-English/MotorOil/Car_Care/AskMobil/Group_3_Base_Oils.aspx

This statement officially says nothing. No substance, just drink the kool aid!!