MoS2 settles in transfer case.

[GMorg]

I have been experimenting with trying to replace VersaTrak fluid wherever I can on a 2005 Montana SV6 - it is now $32 per PINT. I have given up on the rear drive module(RDM). Nothing has been satisfactory except for VersaTrak fluid.

In the transfer case (TC), I decided to try Castrol HypoyC (6 ounces) with LubroMoly MoS2 engine supplement (1 ounce) -7 oz capacity. Since I had seen metalic particles at the initial TC drain, I decided to do a couple of flushes with the same concoction each about a month apart. Everything seemed fine. The drained fluid appeared very gray from the MoS2. On the last flush, I switched to straight RP SynchroMax that I had left over from experimenting with the RDM. I decided to flush the dregs of the old fluid from the bottom drain hole and the tube on the end of my syringe scraped the bottom of the TC. When I depressed the plunger, large "chuncks" flushed out. I recovered the chuncks and they were clearly MoS2 that had settled out from the previous runs of Hypoy C/LubriMolyMoS2. I supposed that since the gear oil doesn't have much in the way of dispersants or detergents, the colloidal MoS2 settle in my case may not represent engine oil.

There doesn't seem to be any harm done, but MoS2 was clearly settling out of the Hypoy C in a daily driven TC. I am convinced that opaque gray oil at drain CANNOT be used as evidence that MoS2 stays in suspension. My drains were gray AND MoS2 was settling out.

Just a warning...

 

[Lead Shoes]

I too used some MOS 2 in my car last oil change, when I drained it, JUST after driving it pretty hard to warm up the oil, the first thing to drain out was gray particles MOS2, I can conclude it must settle to the bottom quite quickly, but its most defiantly stirred up while you are driving.

 

[GMorg]

The stuff in the bottom of my TC was a gooey layer on the bottom that did not drain without dislodging. The dislodged MoS2 was the consistency of clay.

 

[asiancivicmaniac]

Was this ever meant to be used for anything besides engines?

 

[m37charlie]

Originally Posted By: asiancivicmaniac
Was this ever meant to be used for anything besides engines?


I don't think something that's insoluble in base oils should be used, period.

Charlie

 

[mechtech2]

This has not been noted in engines.

I will say that I have seen gray goo in many differentials -with no additives at all.

 

[GMorg]

I did not run an analysis, but I am fairly sure that the sediment was MoS2. It was reminiscent of graphic in appearance. If you have ever worked with potters clay, it was similar except that it was smoother or slicker. When I pinched it with fingers, it did not squeeze out. However, when I rotated my thumb in a circular motion over my finger pad, the lumped would easily disperse into somthing with a texture like grease.

I am particularly curious if the detergents/dispersants in motor oil explains the difference.

 

[Trav]

Wrong Liqui Moly product for use in the transfer case, this is the one.

http://www.liqui-moly.de/liquimoly/produ...voiladb=web.nsf

 

[Cup of Joe]

It sounds like ferrous wear material. If you still have the gray mass check it with a magnet.

 

[sdan27]

I've done several UOAs with MoS2. I take the sample midstream and it always comes back with a hefty amount of Moly.

 

[GMorg]

Trav: I recognize that LiquiMoly makes a gear additive. The MoS2 would be the same as the motor oil additive except for the particle size perhaps. I am curious if it has any additives that keeps it in suspension in gear oil.

TaterandNoodles: I don't think that it was iron. However, I don't have any data to share as proof.

sdan27: There was still a "hefty" amount of MoS2 in the gear oil that I drained. I could not see through it. The point was that a hefty amount in the drain does not mean that it did not settle too.

 

[Trav]

I've been thinking about this. I think this transfer case uses a clutch pack, if it does the last thing you want in there is moly, the grey matter could be clutch material from clutch slippage like the grey stuff commonly found in AT pans, just a thought.

 

[GMorg]

From the diagrams that I found, it does not appear to have clutch packs. The TC is mated to a 4T645-E transmission.

 

[Trav]

Oh okay i was reading this and thought it had the clutch they mention up front but i guess its in the unit in the rear diff. Is that right?

Quote:
New Venture Gear crossover power transfer unit equipped vehicles are normally front wheel drive and have an optional 4WD/AWD package. Crossover power transfer units equipped vehicles are unique because the front final drive gear ratio is different from the rear axle gear ratio. This means that the propshaft rotates at a different speed than the front drive axles. Crossover power transfer units are full time 4WD/AWD systems. This system utilizes a gerotor pump to actuate a clutch mechanism in series with the pinion gear of the rear differential or in the transfer unit to connect the power flow from the power transfer unit to the wheels. There is no 4WD Low on this type of power transfer unit.

 

[GMorg]

Trav:
Yes, there are 7 clutch plates in the RDM. The design may be good on paper, but in practice I really don't like this set-up.