Author Topic: Greasy Question  (Read 614 times)

Ben

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Greasy Question
« on: September 30, 2017, 10:27:26 AM »
Okay, Trailer Park Boys reference in the subject line.  :laugh:

Question on lubricating grease for those in the know. For lubing my 4Runner's prop shaft, Toyota calls for two different lubes. For the spiders, Lithium based NLGI #2. For the slide yokes, moly disulfide lithium NLGI#2. This requires two grease guns to do the job.

While I understand the reasoning for the moly on the slide yokes (salt and water resistance, among other things), I don't understand why I can't use the moly on the spiders as well. What potential detrimental effects can their be for using the moly everywhere, given that it's still lithium based?
"I'm a foolish old man that has been drawn into a wild goose chase by a harpy in trousers and a nincompoop."

dogmush

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Re: Greasy Question
« Reply #1 on: September 30, 2017, 10:35:44 AM »
Molybdenum disulfide, when added to grease, actually decreases the wear resistance of the grease, and my understanding is it's not great for wet areas. It can actually lead to galvanic corrosion issues in wet environments.


It tends to do very well in protected slide situations but wouldn't be my choice for universal joints.  (Or apparently Toyota's either)

Ben

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Re: Greasy Question
« Reply #2 on: September 30, 2017, 10:44:36 AM »
Molybdenum disulfide, when added to grease, actually decreases the wear resistance of the grease, and my understanding is it's not great for wet areas. It can actually lead to galvanic corrosion issues in wet environments.


It tends to do very well in protected slide situations but wouldn't be my choice for universal joints.  (Or apparently Toyota's either)

That's interesting. Maybe I was reading wrong about the water protection. So then opposite question, why not just use regular lithium all the way around? Especially for a service that's recommended every 10K or so? It doesn't seem like you need any special long-life properties in the grease with that frequency of servicing. My analog is dino oil and synthetic (which could be a false analogy) -- if you change oil every 3K, what great advantage would synthetic have, vs the advantage it has for longer oil change intervals?

I'm already using two grease guns, so this is all academic at this point, but I'm just curious, having just greased everything again yesterday.
"I'm a foolish old man that has been drawn into a wild goose chase by a harpy in trousers and a nincompoop."

Jim147

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Re: Greasy Question
« Reply #3 on: September 30, 2017, 10:54:05 AM »
If you take it to a shop to have them do it they will use whatever is in the five gallon/55 gallon air operated gun.
Sometimes we carry more weight then we owe.
And sometimes goes on and on and on.

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dogmush

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Re: Greasy Question
« Reply #4 on: September 30, 2017, 11:43:14 AM »
That's interesting. Maybe I was reading wrong about the water protection. So then opposite question, why not just use regular lithium all the way around? Especially for a service that's recommended every 10K or so? It doesn't seem like you need any special long-life properties in the grease with that frequency of servicing. My analog is dino oil and synthetic (which could be a false analogy) -- if you change oil every 3K, what great advantage would synthetic have, vs the advantage it has for longer oil change intervals?

I'm already using two grease guns, so this is all academic at this point, but I'm just curious, having just greased everything again yesterday.

MoS2 grease is very good at sliding parts.  I'd assume (without having looked) that the slide joints have a wiper and lip seal to help against water intrusion.  The U-Joint spiders have straight roller bearings, which actually get up to a pretty good RPM.  The longer lasting straight lithium is probably better there.  I'd assume Toyota was optimizing their drivetrain lubrication, and they already had both lubricants in the factory.  So they used the correct one for the application.  That part just happens to have two very different kinds of movement to lubricate.

Install 4 wheel independent suspension with fixed differentials and you won't have this problem.   =D

Hawkmoon

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Re: Greasy Question
« Reply #5 on: September 30, 2017, 11:51:09 AM »

Install 4 wheel independent suspension with fixed differentials and you won't have this problem.   =D

Independent suspension does not, per se, dictate that the drive line will use CV joints rather than u-joints.
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