Sorry...really dumb question...what is MoS2?

Wrecked944 · 08-08-2002, 02:36 PM

I'm really sorry to ask this because I suspect everyone will know the answer except me. My snazzy new factory manual says to use "MoS2" paste during transmission re-assembly. But the guys at all of the local auto stores looked at me like I was high on crack when I asked for it. So I searched the Pelican archives and got the impression that everybody here already knows what it is - but I couldn't figure it out !! A google search provided a name "Molybdenum Disulfide"...but no associated car products. So I hate to have to ask but...what is it? Is it a product or ingredient that actually goes by a different name in the auto store? Is it related to "molykote" (another word which I don't grasp)...I'm sorry if this is like asking "What is antifreeze"? I normally try pretty hard not to be this clueless...

Thanks,

widebody911 · widebody911's Garage

http://www.mscdirect.com/PDF/PDF02/2809.pdf

http://www.mbendi.co.za/mobilsa/prodserv/datasheets/auto/auto25.stm

http://www.youngsmp.com.au/lubrcant.htm#Greases.

Early_S_Man · 08-08-2002, 03:01 PM

Janus,

More commonly referred to as 'Moly' ... it is an extreme pressure additive used in greases such as Swepco 101 and Valvoline #986 SynPower Synthetic Grease with Moly ... and gear oils such as Swepco 203 and 212

It is often the principal ingredient in assembly lube used for installing new camshafts, and in transaxles and transmissions, as you found out.

Jim Sims · 08-08-2002, 03:03 PM

The stuff specified is a sticky paste with a very high Molybdenum Disulphide powder content; it is neither a spray nor a grease. It took me a while to find it as most suppliers try to give you the spray or grease. I'll have to look up my records at home. Molykote is a trade name but I believe within that product line there is a moly disulphide paste. I recall this paste was specified for use on the small bevel gears within the differential. One professional transmission rebuilder I talked to said he didn't bother using it; instead he just coated everything with Swepco. Since I had already bought the stuff I applied it to the differential gears per the factory shop manual. Jim

Wrecked944 · 08-08-2002, 03:11 PM

Aaah...that is huge...HUGE....going from PepBoys directly to Pelican is like entering another freakin' dimension...thanks very much for that info...unbelievable difference after having teenagers stare blankly at me saying, "Ummm...I think the oil stuff is over there."...ugh !!

Thanks again,

Early_S_Man · 08-08-2002, 03:18 PM

Here is what I use ...

Wrecked944 · 08-08-2002, 03:33 PM

Whoa...German words on the tube...do you get it mail order or is it available over the counter?

Thanks,

Eric Coffey · 08-08-2002, 05:04 PM

Janus-

The Liqui-Moly stuff is great, and is definitely available in the US. It is just re-badged as "Lubro-Moly" over here. They also make other quality products like valve cleaner, FI cleaner, etc. If you do an internet search for "lubro-moly", "Jectron", and "ventil Sauber", you should find plenty of links/suppliers.

Doug Zielke · 08-08-2002, 05:25 PM

Is this the same stuff the Porsche workshop manuals say to use on the head stud threads, before torquing?

Jim Sims · 05:58 PM

Janus, The stuff I have and used is the same as what Warren posted. LIQUIMOLY or LUBRO Moly Assembly Lube, it has 3 different numbers on it: LM48, LM3010 and Art. Nr. 3010. It's a 50 gram tube and yes it came from Germany. Send me your e-mail address via a private message and I'll tell you where I purchased it. Cheers, Jim

Early_S_Man · 08-08-2002, 05:56 PM

Doug,

The first time Moly was specified on the head stud nuts was in the '84-'87 Spec book, and that is when the torque measurement was changed to a 90° +/- 2° angle ... from the previous mkp or Nm measurements without Moly. Optimoly HT was specified as the product to use on cam bolt threads and head stud nuts.

Doug Zielke · 08-08-2002, 06:10 PM

Right, Warren....it's Optimoly HT that the manual recommends. And is that stuff different from the blue tube you showed in your post? Thanks.

Early_S_Man · 08-08-2002, 07:38 PM

Doug,

I assume they are quite similar ... MoS2 paste ... similar application ...

I have never seen the Optimoly HT for sale by any Porsche parts supplier ... and a google.com search only turned up 1 hit ... a German maintenance manual for a 'wire cage machine' that uses 200 Amps of 3-phase AC power!