[tinkerman]

I recently had to replace my rear right window regulator, and the original BMW regulator I removed has at least two different types of greases. I searched ISTA-D and found no info regarding BMW's recommended greases for window regulators.
Does anyone know for certain what type of greases these are?

1. Grease On Regulator Rail and Spool
On the new original BMW regulator, I could see on the window clip an opaque white grease (looked a lot like silicone grease). On the original BMW regulator that was removed, the grease color is (currently) yellowish opaque brown.
My assumption at the moment is that if the greases are the same in the old and new parts, the grease starts off opaque white then gradually after many years(16 in this case) it turns to a yellowish opaque brown and also thickens up (likely due to oil loss leaving only the thickener).
*Note Attached Photos No.1 & 2:
No.1. Power Window Regulator (E91 E90 Rear Right 2005-2011)
No.2. Regulator Rail Grease On Broken Clip Piece

If the original part's grease was originally this opaque brown color, then I'd like to determine what it is, and why the new part has an opaque white grease and what it is as well.

I also removed the cable spool and noticed an opaque yellowish grease which I think is likely the same as that on the rail, just not turned to brownish color perhaps because it was less exposed.
*Note Attached Photo No.3 Grease On Cable Spool

2. Grease On Upper Pulley
Upon closer observation of the upper pulley's hub, I noticed an off-white cream colored grease. The pulley rotates just fine and smoothly. This cream colored grease is definitely a different grease from the one on the regulator's rail and cable spool.
*Note Attached Photo No.4 Grease On Upper Pulley

I initially thought lithium(?) grease, but realized that greases with calcium* or aluminum* thickeners can also be white-ish colored, so I'm keeping an open mind about it, until more info points me in the right direction.
If I were to re-grease this pulley, it would be a good idea to use a compatible grease if not the same type of grease, even if I made efforts to flush out or clean the old grease in the hub of the pulley, as any remnant of the old grease and an incompatible new grease could degrade and shorten the lifespan of the new grease.
*Update: According to a lubricant manufacturer ECL(Engineered Custom Lubricants) in their "Tips on Lubricating Plastics"(pdf):
"Silicone oil mixes only with lithium, silica, and PTFE."

I'm looking into the topic of determining greases by color and solubility testing and will update when I can. For the time being, I have tried putting a small sample of the brownish grease in 95% ethanol for over 2 hours, and it did not dissolve at all, even with rigorous agitation with a stainless welding wire. Silicone grease is supposedly not soluble in ethanol, whereas petroleum based greases are 'miscible'(emulsion forming) in ethanol. Still this is not a decisive method to clearly determine that the test sample is silicone grease, so I'll have to look into it some more, and update if I can.

If any ya'll are "grease experts"(a real 'thing' ), chemical engineers, or just happen to know through "original sources" what the actual greases are in the regulator shown above, please do comment below... any pointers would be a treat.

[The Nightman]

I don't know the exact greases used but I assume they are silicone based for plastic compatibility. Maybe one of them is Molykote 33?

You may have more luck on the bobistheoilguy forums: https://bobistheoilguy.com/forums/forums/grease.2/

[tinkerman]

Originally Posted by The Nightman

... Maybe one of them is Molykote 33?...

Thanks for the pointer... I was misled by some info thinking lithium greases are petroleum based, but apparently not all of them are as Molykote 33 is silicone oil based with lithium stearate soap(thickener) according to its SDS.

I'll scope out the other forum too. Cheers~

[tinkerman]

Lubricant manufacturer ECL(Engineered Custom Lubricants) makes & markets a lubricant for window regulators - UltraSil 1132 a silicone oil based grease with PTFE thickener! This is the first and only lube(so far) that I've encountered online that is specifically marketed as a grease for window regulators. According to its TDS:

"UltraSil 1132 is a silicone damping grease with a polytetrafluoroethylene thickening agent. This grease is useful for plastic on plastic or plastic on metal applications and was formulated for use in window regulators. It provides effective damping at high and low temperatures and has very low oil separation properties."

ECL has many other similar greases that are "useful for plastic on plastic or plastic on metal applications", but UltraSil 1132 is the only one that is supposedly "formulated for use in window regulators."

Attached is its TDS to note its specifications, if anyone would like to seek a comparable retail product*.
*ECL seems to be a B2B business (I could not find a retail product for UltraSil 1132).
If any ya'll can recommend an equivalent formulation retail grease product, I'm ALL EARS!

[Brian86]

I like Molycote 1292. Fluro-Silicon white paste. Also an Excellent O-ring lubricant for the cooling system, intake manifold, and injector gaskets & rings.

Should be able to get it from the commercial industrial catalogues. Grainger, MSC, Applied.

[The Nightman]

Originally Posted by tinkerman

Lubricant manufacturer ECL(Engineered Custom Lubricants) makes & markets a lubricant for window regulators - UltraSil 1132 a silicone oil based grease with PTFE thickener! This is the first and only lube(so far) that I've encountered online that is specifically marketed as a grease for window regulators. According to its TDS:

"UltraSil 1132 is a silicone damping grease with a polytetrafluoroethylene thickening agent. This grease is useful for plastic on plastic or plastic on metal applications and was formulated for use in window regulators. It provides effective damping at high and low temperatures and has very low oil separation properties."

ECL has many other similar greases that are "useful for plastic on plastic or plastic on metal applications", but UltraSil 1132 is the only one that is supposedly "formulated for use in window regulators."

Attached is its TDS to note its specifications, if anyone would like to seek a comparable retail product*.
*ECL seems to be a B2B business (I could not find a retail product for UltraSil 1132).
If any ya'll can recommend an equivalent formulation retail grease product, I'm ALL EARS!

Super Lube silicone grease with PTFE appears to be quite similar and is also NLGI Grade 2. Marketed for brake parts and o-rings, but I suspect they're the same product:

https://www.super-lube.com/silicone-...-with-syncolon
https://www.super-lube.com/o-ring-silicone-grease