Robin 993DX

Dude, I think stuff started to fail on my 993 after it was parked for 6 month when I was in miami....

First it was the valve cover gasket and then the hydraulic lifters..... Now electrical problem.... it doesn't pay to park the car... Drive it

Flying Finn

Absolutely! Plus knowing you, you need to spend some time under the car too!

Leland Pate

Chris Cervelli told me to only use Mobil 1 75w90 SHC in my gearbox because it needs a friction modifier.

I haven't been able to find any of that stuff anywhere. I can buy 75w90 all day long, but no one can get me the SHC.

the_buch

For those of us with LSDiffs, what additives should be considered with any of these products??

cowtown

I had never heard of Mobil 1 SHC, so I started poking around the Web - I need to change my gear oil soon. I didn't find anything definitive, but this is from a GM board. Anyone know if the below is true?

At one time, Mobil used to call their consumer synthetic gear oil "Mobil 1 SHC 75W-90." It's still called this in Europe. About 10 or so years ago they just called it "Mobil 1 Gear Oil" to better identify with their consumer "Mobil 1" products.

The Mobil 1 Gear Oil for consumer use is apparently based on Mobil's commercial product, Mobil MobilLube SHC 75W-90.

(from http://www.gm-trucks.com/forums/lofi...p?t26178.html)

Leland Pate

Cow,
I asked the same question several months ago after installing my new gearbox. From what I've been told the SHC has a friction modifier necessary for proper LSD operation. I've heard it can be found at Semi truck servicing facilities because it is considered a commercial lubricant. It is not sold in stores (that I've been able to find) and usually comes in 55 gal drums.

If someone can hook it up with some Mobil 1 75W 90 SHC, I would greatly appreciate it!

graham_mitchell

I had great results using Motorex Prisma ZX SAE 75W/90 which is also GL 4/5

cowtown

The way I read that quote from the GM board, the Mobil 1 75w90 you get in quart jugs at the FLAPS is the same thing as the old 75w90 SHC. In a branding move, they just badged it Mobil 1 to align it with the other oil products. Dunno if it's true.

At any rate, I just picked up 4 quarts of the consumer 75w90 M1, and will put it in this afternoon. I had very good luck with it in my G50 '88 targa.

BobbyT

I've had the MTL-R in the gearbox for about a week now, and I think it offers a worthwhile improvement in shift quality, at least from my experience. I was having just a little mechanical feel that I didn't like shifting into third when the gearbox was cold, like I could feel the dog teeth engaging. This feeling is reduced with MTL-R to the point I really have to concentrate to feel it at all. Once the gearbox is warmed up, all shifts are like butter.

Robin 993DX

Bobby,

Good to hear the positive results.

From my experience with the MTL-R is that it improves with some miles too... I don't know the reasoning behind that, maybe after couple hundred miles the oil really get into the components? Don't know... But my 996 definitely is shifting better with time on the MTL-R.

the_buch

Robin ... did you have to put in any limited slip additive for your 4-wheel drive 996 (assuming it has a LSD)??

Thanks,

Robin 993DX

my 996 didn't come with lsd.. it was an option for the c4

I would address the question to the good folks at Specialty formulation

bgiere

Mobil SHC is now called Mobilube Delvac 75w90...available from Lufteknik (sic)...see my other post.

pguy

Hi Brant,

Do you have the website of this place Lufteknik? I googled but couldn't find it.

Thanks,
pguy.

Pete Lech

Don't forget the tip to leave your car parked in second gear.

It really helps the grinding going into second while starting up cold.