I wondered about this someone in the VW forums claimed that it would be better. The Bentley manuals recommend white lithium.
Anyone an expert on this here?
Anyone an expert on this here?
Silicone grease > white for vw shifter bushings?
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I'm no expert - never owned a VW, never even worked on one.
But I don't think one needs to be to think this question through to a good recommendation.
What materials are being greased? Or, better said, what materials are the shifter bushings and what material goes through them?
If they are plastic or rubber, silicone grease would be the natural choice as it won't attack the rubber or plastic.
I hunted around and it seems that most lithium greases (the tub kind, not the aerosol) do have a petroleum base oil that will eventually degrade plastics and rubbers. The aerosol MSDS' vary considerably depending on the manufacturer, but it seems they can have a solvent as well as the petroleum base that wouldn't be good for common plastics.
Sure, there are some really really good engineering plastics out there with long-term solvent resistance, but it's a matter not of "if" but of "when" when you talk degradation.
One exception would be if the rubber is a silicone rubber, then silicone grease will degrade it and a petroleum product is okay.
Often you'll see advice to use silicone spray on your weatherstripping - the weather stripping is not affected by the silicone.
If they are metal, I don't think you can go wrong with *any* grease from white lithium on up. Thinking about it, a shifter bushing doesn't see vast rotation, isn't heavily loaded, etc...
That's my few thoughts...
later,
b
But I don't think one needs to be to think this question through to a good recommendation.
What materials are being greased? Or, better said, what materials are the shifter bushings and what material goes through them?
If they are plastic or rubber, silicone grease would be the natural choice as it won't attack the rubber or plastic.
I hunted around and it seems that most lithium greases (the tub kind, not the aerosol) do have a petroleum base oil that will eventually degrade plastics and rubbers. The aerosol MSDS' vary considerably depending on the manufacturer, but it seems they can have a solvent as well as the petroleum base that wouldn't be good for common plastics.
Sure, there are some really really good engineering plastics out there with long-term solvent resistance, but it's a matter not of "if" but of "when" when you talk degradation.
One exception would be if the rubber is a silicone rubber, then silicone grease will degrade it and a petroleum product is okay.
Often you'll see advice to use silicone spray on your weatherstripping - the weather stripping is not affected by the silicone.
If they are metal, I don't think you can go wrong with *any* grease from white lithium on up. Thinking about it, a shifter bushing doesn't see vast rotation, isn't heavily loaded, etc...
That's my few thoughts...
later,
b
Kestas
Staff member
Are the shifter bushings exposed to the elements, or are they considered part of the passenger compartment? If exposed, I would use only silicone grease.
kd5byb, silicone grease can attack silicone rubber? Are you sure? I don't have any information to the contrary, but intuitively it just doesn't seem right.
kd5byb, silicone grease can attack silicone rubber? Are you sure? I don't have any information to the contrary, but intuitively it just doesn't seem right.
Originally Posted By: Kestas
kd5byb, silicone grease can attack silicone rubber? Are you sure? I don't have any information to the contrary, but intuitively it just doesn't seem right.
It depends on the exact grease and exact silicone rubber. Since damage can take some time, it's best to avoid unless you know you have a good combination of silicone grease and silicone rubber. Fluorosilicones resist silicone oils and grease quite well.
There have also been some limited problems with brake system seals when DOT5 silicone fluid is used in conventional brake systems. The problems occur in brake systems with silicone based seals and can take some time to occur.
Here's a link to o-ring compatibility that might help
http://www.efunda.com/designstandards/oring/oring_chemical.cfm?SM=none&SC=Silicone Oils#mat
kd5byb, silicone grease can attack silicone rubber? Are you sure? I don't have any information to the contrary, but intuitively it just doesn't seem right.
It depends on the exact grease and exact silicone rubber. Since damage can take some time, it's best to avoid unless you know you have a good combination of silicone grease and silicone rubber. Fluorosilicones resist silicone oils and grease quite well.
There have also been some limited problems with brake system seals when DOT5 silicone fluid is used in conventional brake systems. The problems occur in brake systems with silicone based seals and can take some time to occur.
Here's a link to o-ring compatibility that might help
http://www.efunda.com/designstandards/oring/oring_chemical.cfm?SM=none&SC=Silicone Oils#mat
Great post XS650 and thanks for the link!
I used to have a Parker O-ring catalog that was great for looking up compatible chemicals in a situation like this. Unfortunately, that was ten years and several moves ago and I can find it and they don't have it online.
As XS650's link shows, there are lots of rubbers out there. If you know the specific type of rubber, you can look it up and see what is compatible. If you don't know the type used in an auto application, the silicone grease will be safe.
One of my favorites is either missing or listed with a chemical name instead of the duPont tradename, which is Viton. Army turboshaft engines use them for sealing off JP-8 (jet fuel) and 23699 (jet engine oil). It's good stuff.
Now to the question as to silicone with a silicone rubber and why it is actually intuitive why silicone oil would attack silicone rubber. Actually, I shouldn't say "attack," I should say dissolve. It's also easiest to dissolve a material in a like material.
For instance, petroleum grease doesn't dissolve in water. But it dissolves well in kerosene, which is a petroleum product.
Same with silicone oil and silicone rubber - the silicone rubber easily dissolves in the silicone oil because they are very similar. As XS650 pointed out, fluorosilicones are excepted from this example.
later,
b
I used to have a Parker O-ring catalog that was great for looking up compatible chemicals in a situation like this. Unfortunately, that was ten years and several moves ago and I can find it and they don't have it online.
As XS650's link shows, there are lots of rubbers out there. If you know the specific type of rubber, you can look it up and see what is compatible. If you don't know the type used in an auto application, the silicone grease will be safe.
One of my favorites is either missing or listed with a chemical name instead of the duPont tradename, which is Viton. Army turboshaft engines use them for sealing off JP-8 (jet fuel) and 23699 (jet engine oil). It's good stuff.
Now to the question as to silicone with a silicone rubber and why it is actually intuitive why silicone oil would attack silicone rubber. Actually, I shouldn't say "attack," I should say dissolve. It's also easiest to dissolve a material in a like material.
For instance, petroleum grease doesn't dissolve in water. But it dissolves well in kerosene, which is a petroleum product.
Same with silicone oil and silicone rubber - the silicone rubber easily dissolves in the silicone oil because they are very similar. As XS650 pointed out, fluorosilicones are excepted from this example.
later,
b
Kestas
Staff member
Thanks, your explanation now makes it intuitive.
Hey thanks for the insight kd5byb!
I really don't know the exact make up of the parts. Although I am sure with a 12 year old Golf that none of the busings are silicone. They are likely rubber based or more likely plastic based.
I think I will take a chance on the silicone grease any preferences out there for which grease to go with. A recommmended one that you can find readily available at the auto parts chain store ? Thanks
I really don't know the exact make up of the parts. Although I am sure with a 12 year old Golf that none of the busings are silicone. They are likely rubber based or more likely plastic based.
I think I will take a chance on the silicone grease any preferences out there for which grease to go with. A recommmended one that you can find readily available at the auto parts chain store ? Thanks
NAPA carries SYL-Glyde, it is great stuff
Kestas
Staff member
If you can cut a sliver of elastomer from some innocuous place, there's a quick way to tell if you have a silicone elastomer or a carbon-based elastomer. Burn it, then look at the char. If it's silicone, the char will be white. Otherwise the char is black.
tom,
so can you get syl glide in a brush on form. I really don't like the spray on type due to the fact that I don't like the though of stray amounts of the stuff getting near the O2 sensor or the like.
so can you get syl glide in a brush on form. I really don't like the spray on type due to the fact that I don't like the though of stray amounts of the stuff getting near the O2 sensor or the like.
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