Ok, there have been so many threads about drive shaft greasing, thought it'd be a good idea to make a reference thread...
Here is the FSM picture. I have changed the numbering to match the TSB for consistency.
Sorry if the notations don't show up on the pic, I edited it in photobucket and they don't seem to show up right sometimes...
4Runners.org has some great pictures of the zirk locations, but glosses right over the grease issue.
4Runners.org - Lubing Your Driveshaft
The FSM on page PR10 says to apply molybdenum disulfide lithium based chassis grease to the slip yokes only (zirk's 2 and 7). The spider bearing replacement page says to pack the spider bearings with MP Grease (Multi-purpose grease, usually lithium based, zirks 1, 3 and 8).
And on page MA-9, it specifies Moly grease for the Double Cardan joints (thanks for the find here MTwEeZi!)
So in summary:
1. MP
2. Moly
3. MP
4. Moly
5. Moly
6. Moly
7. Moly
8. MP
This was all pulled from the FSM dated 2002 (only one I have seen posted online)
Then there is a TSB from 1999 that says differently
1. MP
2. MP
3. MP
4. Moly
5. Moly
6. Moly
7. MP
8. MP
I notice that the manual and the TSB reverse the direction of the zerk on the center carrier of the double cardan. Mine is like the TSB, facing the rear.
If you have broken or lost a zerk!
Replacement zerks can be purchased at a variety of retailers. The size of the zerks is 6mm.
I am not sure the thread pitch is 1mm or 0.75mm, both have been stated here. If you find out, please PM me so I can update this post with that info.
A little background on Moly vs non-moly... Ok, got some real sources now... BOOKS!
Molybdenum disulphide lubrication By A. R. Lansdown
Molybdenum disulfide (MoS2) is a naturally occurring molecule (known as Molybdenite) that been used as a lubricant for hundreds of years. It has been used on wooden wagon wheels, on early manufacturing and machining equipment, and other applications. It was even used as rust protectant. It has been produced all over the world, first primarily Australia, but later it mostly came from a huge deposit in Climax Colorado. Now it is produced all over the world. Despite its clear superiority to other lubricants of the day (talc and graphite), Moly never caught on as a mainstream solid lubricant until WWI.
It is very similar to graphite, but is better able to withstand high pressure and high heat. The molecules form small plates that act as lubricant. They fill in the microscopic pits and valleys on the surface of a metal forming a layer (this is due to strong adhesive and cohesive properties paired with an affinity for metals). This can eventually build up a layer of molybdenum sulfide on a lubricated metal surface. This layer can reach a maximum thickness of 1.2um.
Moly grease is just regular lithium (or other base, lithium seems to be most common) grease with a molybdenum disulfide additive in it that acts as a dry lubricant. This additive opened the possibility for sealed bearings that didn't need re-lubrication, because even when the oil seeped out, the molybdenum disulfide would act as dry lubricant.
I found this somewhat anecdotal torture test demonstration back in the 70's (sorry, it's just a read, no video)
http://www.beslub.com/torture.htm (Moly product seller, likely biased to pro moly)
very interesting if true.
Un-Qualified statements - These are things I have read multiple places, but not found a real legitimate citation for, so if you have a good source, let me know and I will add the link here:
Sources:
http://schaefferoil.de/sheets/praesentationen/factmoly_en.pdf (Moly Seller - Likely biased for Moly)
1. Moly grease is bad for a non-sealed joints with zirk fitting because you can build up too much solid lubricant as the oil seeps out over time and the joint is re-lubed. Schaeffer oil (sells moly products) claims that this is untrue, and Moly will not build up layers large enough to bind up bearings. Also, they claim that moly will not come out of suspension, and can be stabilized to prevent clumping
2. Moly grease is bad for high speed bearings - This seems to be either untrue, or not the whole story. Several places including Schaeffer claim that moly is popular in high speed/high temp bearings.
3. Our high velocity joints (u-joints, double cardan) should use high temperature grease - Again, multiple places say that high temp is the perfect application for moly.
4. Sulfides will react with brass. Grease with molydenum sulfide should not be used anywhere where brass is used (is brass used in our joint at all? couldn't find this for sure and I havn't taken mine apart). Cuperous sulfides are a corrosion product for brass or other copper based alloys, so this could be true.
That's all for now, will add more as I find them. Let me know if you have any answers (provide citation).
A couple points...
Commercially available moly greases (non-industrial supply, like autozone, wal-mart etc...) are likely lithium based greases with molybdenum additive. Commercially available MP greases are likely lithium based as well. As such, there should not be any incompatibility issues arising from switching back and forth between regular grease and moly grease. Incompatibility comes from mixing different based greases that react with each other.
Here's a nice picture of the internals of our U-joints.
And here are some pics from fishcharmer of his destroyed u-joint. They show how the grease flows through the joint.
So in conclusion...
People use only MP grease on all 8 zirks, and get 100K+ miles out of it.
People use only Moly grease on all 8 zirks, and get 100K+ miles out of it.
I havn't found any non-biased source describing Moly's application to u-joints or non-sealed bearings in general. Lots of claiming Moly is the bee's knees, and others claiming vehemently that moly is snake oil. My conclusion is that it most certainly isn't snake oil, but might might not be necessary/the best for non-sealed bearing like in u-joints. Or maybe it is.
Other Links:
http://forum.ih8mud.com/100-series-cruisers/281147-mobil-1-synthetic-grease-nlgi-no-2-a.html
No need to post any "I only use moly and I am at 300k and my u-joint are perfect..." or the like; the internet is rife with these kinds of posts. Post corrections and good additions and I will add them to the top post. Post citations that are not other forum posts (unless they have a specific point that can be added to the unqualified statements list, or have a citation themselves).
Ok, there have been so many threads about drive shaft greasing, thought it'd be a good idea to make a reference thread...
Here is the FSM picture. I have changed the numbering to match the TSB for consistency.
Sorry if the notations don't show up on the pic, I edited it in photobucket and they don't seem to show up right sometimes...
4Runners.org has some great pictures of the zirk locations, but glosses right over the grease issue.
4Runners.org - Lubing Your Driveshaft
The FSM on page PR10 says to apply molybdenum disulfide lithium based chassis grease to the slip yokes only (zirk's 2 and 7). The spider bearing replacement page says to pack the spider bearings with MP Grease (Multi-purpose grease, usually lithium based, zirks 1, 3 and 8).
And on page MA-9, it specifies Moly grease for the Double Cardan joints (thanks for the find here MTwEeZi!)
So in summary:
1. MP
2. Moly
3. MP
4. Moly
5. Moly
6. Moly
7. Moly
8. MP
This was all pulled from the FSM dated 2002 (only one I have seen posted online)
Then there is a TSB from 1999 that says differently
1. MP
2. MP
3. MP
4. Moly
5. Moly
6. Moly
7. MP
8. MP
I notice that the manual and the TSB reverse the direction of the zerk on the center carrier of the double cardan. Mine is like the TSB, facing the rear.
If you have broken or lost a zerk!
Replacement zerks can be purchased at a variety of retailers. The size of the zerks is 6mm.
I am not sure the thread pitch is 1mm or 0.75mm, both have been stated here. If you find out, please PM me so I can update this post with that info.
A little background on Moly vs non-moly... Ok, got some real sources now... BOOKS!
Molybdenum disulphide lubrication By A. R. Lansdown
Molybdenum disulfide (MoS2) is a naturally occurring molecule (known as Molybdenite) that been used as a lubricant for hundreds of years. It has been used on wooden wagon wheels, on early manufacturing and machining equipment, and other applications. It was even used as rust protectant. It has been produced all over the world, first primarily Australia, but later it mostly came from a huge deposit in Climax Colorado. Now it is produced all over the world. Despite its clear superiority to other lubricants of the day (talc and graphite), Moly never caught on as a mainstream solid lubricant until WWI.
It is very similar to graphite, but is better able to withstand high pressure and high heat. The molecules form small plates that act as lubricant. They fill in the microscopic pits and valleys on the surface of a metal forming a layer (this is due to strong adhesive and cohesive properties paired with an affinity for metals). This can eventually build up a layer of molybdenum sulfide on a lubricated metal surface. This layer can reach a maximum thickness of 1.2um.
Moly grease is just regular lithium (or other base, lithium seems to be most common) grease with a molybdenum disulfide additive in it that acts as a dry lubricant. This additive opened the possibility for sealed bearings that didn't need re-lubrication, because even when the oil seeped out, the molybdenum disulfide would act as dry lubricant.
I found this somewhat anecdotal torture test demonstration back in the 70's (sorry, it's just a read, no video)
http://www.beslub.com/torture.htm (Moly product seller, likely biased to pro moly)
very interesting if true.
Un-Qualified statements - These are things I have read multiple places, but not found a real legitimate citation for, so if you have a good source, let me know and I will add the link here:
Sources:
http://schaefferoil.de/sheets/praesentationen/factmoly_en.pdf (Moly Seller - Likely biased for Moly)
1. Moly grease is bad for a non-sealed joints with zirk fitting because you can build up too much solid lubricant as the oil seeps out over time and the joint is re-lubed. Schaeffer oil (sells moly products) claims that this is untrue, and Moly will not build up layers large enough to bind up bearings. Also, they claim that moly will not come out of suspension, and can be stabilized to prevent clumping
2. Moly grease is bad for high speed bearings - This seems to be either untrue, or not the whole story. Several places including Schaeffer claim that moly is popular in high speed/high temp bearings.
3. Our high velocity joints (u-joints, double cardan) should use high temperature grease - Again, multiple places say that high temp is the perfect application for moly.
4. Sulfides will react with brass. Grease with molydenum sulfide should not be used anywhere where brass is used (is brass used in our joint at all? couldn't find this for sure and I havn't taken mine apart). Cuperous sulfides are a corrosion product for brass or other copper based alloys, so this could be true.
That's all for now, will add more as I find them. Let me know if you have any answers (provide citation).
A couple points...
Commercially available moly greases (non-industrial supply, like autozone, wal-mart etc...) are likely lithium based greases with molybdenum additive. Commercially available MP greases are likely lithium based as well. As such, there should not be any incompatibility issues arising from switching back and forth between regular grease and moly grease. Incompatibility comes from mixing different based greases that react with each other.
Here's a nice picture of the internals of our U-joints.
And here are some pics from fishcharmer of his destroyed u-joint. They show how the grease flows through the joint.
So in conclusion...
People use only MP grease on all 8 zirks, and get 100K+ miles out of it.
People use only Moly grease on all 8 zirks, and get 100K+ miles out of it.
I havn't found any non-biased source describing Moly's application to u-joints or non-sealed bearings in general. Lots of claiming Moly is the bee's knees, and others claiming vehemently that moly is snake oil. My conclusion is that it most certainly isn't snake oil, but might might not be necessary/the best for non-sealed bearing like in u-joints. Or maybe it is.
Other Links:
http://forum.ih8mud.com/100-series-cruisers/281147-mobil-1-synthetic-grease-nlgi-no-2-a.html
No need to post any "I only use moly and I am at 300k and my u-joint are perfect..." or the like; the internet is rife with these kinds of posts. Post corrections and good additions and I will add them to the top post. Post citations that are not other forum posts (unless they have a specific point that can be added to the unqualified statements list, or have a citation themselves).
Climb under your truck... it'll all be there for viewing. You'll need a grease gun (or two) with the right grease. Front driveshaft should spin easily by hand as long as you aren't in 4WD. Rear driveshaft will need one rear tire lifted and the e-brake off and trans in neutral (chock the wheels!) to spin. Pump some grease until good grease starts coming out, other than on the slip joints where you should just do a couple pumps.
. Does it smell like Chinese food? McDonalds? Seriousness aside, if it doesn't go away soon, maybe have another look underneath.The spinning driveshaft does splatter grease all around once you start driving, perhaps some of it got onto the exhaust/muffler and is cooking
