G50 trans oil change, whats needed?

[bklyn]

Gents, I plan on draining the gear lube in my 1897 911 3.2 soon. Can you advise the correct type of fluid and how much it will take to refill. Some say use Swepco but other say not to for a G50 trans.

[Flieger]

Mobil 1 Delvac for G50s

The earlier Porsche syncros in the 915 need the friction of the Swepco. Getrag B/W syncros do not like it so much.

[bklyn]

Great, about how many quarts do you think?

[Vino]

Originally Posted by bklyn

Great, about how many quarts do you think?

As per manual, 3.17 qts. or 3.0 liters.
The Mobil 1 Delvac seems to be the best choice here, Porsche uses it some of the factory race cars. Try a Truking/Semi warehouse, they may have some.
I'll use this the next time to compare...

Since it didn't exsist around me and I was on a short time frame, I used Royal Purple and it's been excellent.

[KTL]

Lufteknic and LN Engineering carry the Mobil Delvac in one gallon bottles. That will provide you plenty.

Note you'll need a 10mm hex key or need to double-nut a 10mm-head bolt to get the fill and drain plugs out. These are notoriously stubborn and overtightened, so be ready.

[Vino]

Just to add, if the car is on level ground, when it just begins to pour out I believe it is perfect. I let it drip out until it stopped from the top plug.
I also believe the plugs have washers that you can get from our host.

I think the Lufteknic is now Mobil Delvac, otherwise as KTL mentioned, Charles who runs LN Engineering is the man with what you need.

BTW, bolts were so tight on my car, I had to use a special extension and "Jack" to loosen it. The metal extension was bending and finally snapped it loose, it was that bad
Just snug them down where the bolt will be happy to stay put.

[old man neri]

Make sure you open the fill plug first.

Also, I forget what sized I used by I just sourced a giant allen key at the Home Depot and that worked perfectly in conjunction with a hammer. You will also have to work out some sort of contraption to get the fluid back in there. Some use a little hand pump, others use a long hose. Be prepared, it is not as simple as just pouring it in out of a 1 gallon jug.

Does it need crush washers?

[KTL]

Lufteknic Company Porsche Service & Parts

[hcoles]

many swear by Swepco.. I'm using Delvac now.. there are two model numbers of Swepco.. not sure which one is better... there are a lot of threads on this.
I went with Delvac per Charles N.
I've also use Redline... seemed fine.

[KTL]

Swepco 201 is swore by in 915 transmissions.

G50 has all sorts of favorite flavors- Redline, Mobil 1 Delvac, Kendall Super 3 Star, Brad Penn, Swepco (not 201)............ the list goes on.

I believe Charles Navarro uses Swepco 210 in his 964 G50 trans (same thing as the 87-89 trans).?

[BMWDavid]

Mobil SHC gear lube is what you want. Comes in 1 gallon jugs. I got it at the local NAPA. I believe it is now called Mobil Delvac gear lube...not to be confused with Mobil 1 gear lube that you can get at the local auto parts stores.

Royal Purple Gear Max is also a great lube for the G50.

In any case it takes about 3.5 quarts to fill. Just fill until it comes out the fill hole.

Be sure to remove the fill plug first!

David

[MOMO3.2]

Ooooops! I used Mobil 1 Synthetic Gear Oil 75-90 to refill my G50. Is there something wrong with using the standard Mobil 1 Gear oil? Do I need to change out this oil ASAP or what?

The previous threads I checked never referred to "Delvac"...

Mike

[dw1]

MOMO3.2 raises a good question about the Mobil 1 synthetic gear oil versus Mobil Delvac.

The Bentley manual for the 3.2's is not very specific, indicating "Hypoid gear oil SAE 90 (GL-5)".

That manual also states: " Synthetic manual transmission fluid is not approved by the manufacturer, but its use may result in improved transmission performance and wear characteristics. Consult an authorized Porsche Dealer for recommendation on synthetic transmission fluids."

Checking the specs for the two Mobil products doesn't seem to show a big difference:

Mobil Delvac:
http://www.mobil.com/USA-English/Lubes/PDS/NAXXENCVLMOMobil_Delvac_Synthetic_Gear_Oil_75W-90_80W-140.asp

Mobil1 Synthetic Gear Lubricant:
http://www.mobil.com/USA-English/Lubes/PDS/GLXXENPVLMOMobil1_Synthetic_Gear_Lubricant_LS_75W-90.asp

They both are API GL-5, but it does appear that the Delvac is made for slightly higher-temperature service.

Is there a difference between these 2 when used in a G50?

And, if one were to use Delvac, is the 75W-90 better, or the 80W-140, as they both cover the SAE 90W requirement?

[Monza_dh]

Dont forget to remove the fill plug BEFORE you remove the drain plug!!

just in case.....

[BMWDavid]

Originally Posted by MOMO3.2

Ooooops! I used Mobil 1 Synthetic Gear Oil 75-90 to refill my G50. Is there something wrong with using the standard Mobil 1 Gear oil? Do I need to change out this oil ASAP or what?

The previous threads I checked never referred to "Delvac"...

Mike

You can use the Mobil 1 gear oil with out any problem. Its just that the Mobil SHC is what the Porsche factory used in their race cars.

[MOMO3.2]

Thanks David. I did my Pelican homework before I changed my gear oil several months ago and no posts mentioned Delvac--just Mobil 1 75-90 Synthetic. Next time, I know what to do.

Mike

[KTL]

Local parts store single quart Mobil 1 75W90 and Delvac/SHC both work good in G50. I've had good results with both. But Delvac has seemed to perform better- less gear crunching on hot track days. Had I installed a trans temp gauge (still on to-do list), I could provide better "testing" data.

So there's no alarming worry if someone were to use the regular Mobil 1. This situation is not like the endless motor oil discussions where there's been a known reduction in oil additives.

Just be aware that the local parts store Mobil Delvac is NOT the same as Mobil 1 Delvac. You'd be very lucky to find this stuff at a NAPA......

[JeremyD]

What Kevin says - I've had good luck with both.

[88911coupe]

Could someone explain what the term "delvac" means? I've seen this before and wondered if it's a type of gear lube or a trade name.

[rnln]

I used the Mobile1 at autopart store years ago, the one people said it's the "wrong" one. Then I use redline now. Funnything is the "wrong" one give me better feeling.
Make sure to have a good pump, and get ready to stay under there for a while until your hands (the least) get real dirty.