Grease for uni-joints in tail/prop shafts - moly (grey) or lithium (bearing) ? (1 Viewer)

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I have stated here numerous times over the last 8 years that I have used only EP (moly grease) on my trucks in every application for at least 25 years with excellent results. Palladium just happens to be the grease I’ve been using for the last several years.

This subject continues to be revisited over and over no matter how much info is pumped into the archives. Using a single brand/type of grease simplifies matters. I need only one grease gun and I don’t have concerns about different types of grease mixing. Buy Palladium in the ten tube case. I bought my last case at Napa for $64 but that was a couple years ago.
 
I have stated here numerous times over the last 8 years that I have used only EP (moly grease) on my trucks in every application for at least 25 years with excellent results. Palladium just happens to be the grease I’ve been using for the last several years.

This subject continues to be revisited over and over no matter how much info is pumped into the archives. Using a single brand/type of grease simplifies matters. I need only one grease gun and I don’t have concerns about different types of grease mixing. Buy Palladium in the ten tube case. I bought my last case at Napa for $64 but that was a couple years ago.
I buy mine from Amazon these days.
 
Where in the FSM does it talk about how much to actually grease the spider/u-joints and slip yoke? I see on MA-5 that it points out the six zerks. I'm a first timer, can I just put a few pumps in? I know the danger is more on the slip yokes.

I have a slight squeak that has developed when moving from stopped and plan to pick up grease and gun this weekend.

Edit: I'm seeing conflicting information about whether I should be on a lift or have wheels on the ground in neutral, etc. Some good old threads in the Maintenance sticky but I'd like to not remove the driveshaft if I don't have to.
 
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Where in the FSM does it talk about how much to actually grease the spider/u-joints and slip yoke? I see on MA-5 that it points out the six zerks. I'm a first timer, can I just put a few pumps in? I know the danger is more on the slip yokes.

I have a slight squeak that has developed when moving from stopped and plan to pick up grease and gun this weekend.

For the Uni joints, I pump in grease until it pushes out clean grease around all four seals.

Cheap uni joints with soft rubber cap seal will probably let all the grease blow past one seal, which means there's no way to be sure still for bearings on the spider have gotten a fresh load of grease.
OEM or Matsuba joints have an o-ring seal held captive, it takes more pressure from the grease gun to get grease to blow past the seals, and you'll more likely get grease through the whole assembly by the time you see fresh grease at all four corners
 
For the Uni joints, I pump in grease until it pushes out clean grease around all four seals.

Cheap uni joints with soft rubber cap seal will probably let all the grease blow past one seal, which means there's no way to be sure still for bearings on the spider have gotten a fresh load of grease.
OEM or Matsuba joints have an o-ring seal held captive, it takes more pressure from the grease gun to get grease to blow past the seals, and you'll more likely get grease through the whole assembly by the time you see fresh grease at all four corners
The u-joints are original so should be OEM. Does it matter if wheels are on the ground? Read some people saying lift it, others saying just chock the wheels and put in neutral.
 
Edit: I'm seeing conflicting information about whether I should be on a lift or have wheels on the ground in neutral, etc. Some good old threads in the Maintenance sticky but I'd like to not remove the driveshaft if I don't have to.

Wheels on the ground. You most likely need to move the vehicle to get each of the zerks positioned in order to attach the grease gun. Shift the transfer into neutral but chock the wheels for safety as the vehicle will roll even with the transmission in Park.
 
Wheels on the ground. You most likely need to move the vehicle to get each of the zerks positioned in order to attach the grease gun. Shift the transfer into neutral but chock the wheels for safety as the vehicle will roll even with the transmission in Park.
Thanks to you both. I'm clear on the spider/u-joints and will put a pump or two in both fittings for the slip yokes and see if my sound goes away. With a 100+ mile trip coming up, won't have time to do much more before that.
 
EVERYTHING but the Bitfields ....
this is the only way i roll and have so for over 20 years since being turned on to it , 20 years later everything still turns normally per the FSM ..




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I don't know what is currently in there but NAPA was out of nearly everything so ended up buying "Valvoline Automotive General Purpose Amber Grease - Essential Performance NLGI No. 2" It is an amber lithium multi-purpose extreme pressure grease. They didn't have Palladium with 3% moly but FSM calls for a lithium-based so hopefully this is fine.
 
FWIW there's also Valvoline full Synthetic grease (used to be called SynPower) with IIRC 2-1/2% Moly which generally can be found at most auto parts stores in the US (Auto zone for example).

Having said that Valvoline's lubricant business (engine oil grease, gear oil, etc) was recently sold to Saudi Aramco and some products like the Valvoline Palladium seem to have disappeared from the shelves. IDK if that's just a temporary supply issue or??



Chevron also has a few choices for Moly fortified grease:


 
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I don't know what is currently in there but NAPA was out of nearly everything so ended up buying "Valvoline Automotive General Purpose Amber Grease - Essential Performance NLGI No. 2" It is an amber lithium multi-purpose extreme pressure grease. They didn't have Palladium with 3% moly but FSM calls for a lithium-based so hopefully this is fine.
It will be okay, but don't use it on the upper Dingell arm Bushings, that could completely disfabulate both your muffler bearings, and your knuter valves
 
It will be okay, but don't use it on the upper Dingell arm Bushings, that could completely disfabulate both your muffler bearings, and your knuter valves

This guy marzel vanes for sure, make sure your reciprocating dingle arm is always free from torsional amplification and it'll live well into it's ecliptic phase.
 
OK, back to tech.

Mud Grease rule #1: Any compatible* grease is better than no grease or contaminated grease.

*Definitiion of compatible grease: greases that have the same base type.

So Lithium (soap) base is compatible with Lithium base. Aluminum is compatible with Aluminum, Calcium is compatible with Calcium. In general the different base types of grease should not be mixed but there are exceptions so always check the manufacturers specs as to what is compatible with what.

Having said that, if you were in the middle of nowhere and you had a choice between running with very low grease say in a steering knuckle (leading to dry spindle bearings for example) you'd either clean out the old grease first if you could, or use the incompatible grease with what's left in there and then clean it all out once you got back to civilization.

Been discussed many times, and I'm not a Tribologist (lubrication engineer), but this is how I understand it:

The Moly component is there to to decrease metal-to-metal contact under extreme pressure and sliding type loads, like the balls inside the CV joint sliding/spinning inside the cup of the joint or the spindle bushing contact with the bearing surface of the rotating stub shaft of the CV joint. Also Moly tends to stick to metal microscopically which may offer some protection with low grease situations.

Point of all this is, if the spec calls for a Moly fortified grease but all you have is a plain multipurpose grease, then use what you have until you can get the correct grease.

FWIW
 
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What great posts - thank you for the alternate options and for increasing my understanding of grease types. Interesting about the sale to Saudi Aramco...SA is on quite the acquisition/diversification tear recently. Just this morning I was listening to something about their edge in desalination technology.

I had made a mental note to look up why Moly is important in some applications vs others and your post answered it.
FWIW there's also Valvoline full Synthetic grease (used to be called SynPower) with IIRC 2-1/2% Moly which generally can be found at most auto parts stores in the US (Auto zone for example).

Having said that Valvoline's lubricant business (engine oil grease, gear oil, etc) was recently sold to Saudi Aramco and some products like the Valvoline Palladium seem to have disappeared from the shelves. IDK if that's just a temporary supply issue or??
OK, back to tech.

Mud Grease rule #1: Any compatible* grease is better than no grease or contaminated grease.

*Definitiion of compatible grease: greases that have the same base type.

So Lithium (soap) base is compatible with Lithium base. Aluminum is compatible with Aluminum, Calcium is compatible with Calcium. In general the different base types of grease should not be mixed.

Having said that, if you were in the middle of nowhere and you had a choice between running with very low grease say in a steering knuckle (leading to dry spindle bearings for example) you'd either clean out the old grease first if you could, or use the incompatible grease with what's left in there and then clean it all out once you got back to civilization.

Been discussed many times, and I'm not a Tribologist (lubrication engineer), but this is how I understand it:

The Moly component is there to to decrease metal-to-metal contact under extreme pressure and sliding type loads, like the balls inside the CV joint sliding/spinning inside the cup of the joint or the spindle bushing conact with the bearing surface of the rotating stub shaft of the CV joint. Also Moly tends to stick to metal microscopically which may offer some protection with low grease situations.

Point of all this is, if the spec calls for a Moly fortified grease but all you have is a plain multipurpose grease, then use what you have until you can get the correct grease.

FWIW
In any case, I had fun doing this job for the first time. The front driveshaft was easier to work on. The rear, even with moving a few times, I just couldn't get a good angle on the u-joints. The hose fitting was too large/rigid to fit in the gap. Eventually I got it with one hand holding the hose onto the zerk fitting, but did not see old grease coming out. After a short drive my squeak seems to be gone but that could just be from warming up, will see how second leg of trip goes tmrw.

To the jokesters: I used the same grease in my blinker fluid so my knuter valves should be A-ok. ;)
 
IME you can get to a few of the zerks (vehicle on it's tires/wheels, not jacked up) by orienting the zerk upward somewhere between 10-2 O'clock, then coming at the zerk from above using a long rubber hose extension for the nozzle. Also some manufacturer's nozzles are fatter than others, so look for the narrow type that will snap onto a zerk.

Then with one hand holding the nozzle in place on the zerk from above (with the extension hose bent up, around, and down) and the other hand pumping the grease gun. I use the type of gun with a long pump lever which allows you to brace the rear end of the gun on the ground for leverage (ie: working on your back) while pumping the lever with the free hand. Been doing it that way for years, decades.

Pump until you see fresh grease coming out of all the end caps. For the slip yolks pump until you just see the yolk start to move and stop.

If you over-grease the slip yolk/driveshaft you can remove the small zerk (?6-8mm socket or nut driver) and let the pressure out, maybe go for a short drive (slowly) over some bumps to push out the excess grease (of the slip yolk), replace the zerk.

I like clean off any excess/old grease with my fingers (in/around the spider of the U-joint) wiping it into some papertowels to prevent it from getting slung all over including onto the (hot) muffler.

IME, if you do that every 5000-7000 miles your OEM U-joints should last 300,000++ miles.

FWIW I've been using the Valvoline Palladium (3% Moly) for the U-joints (and slip yolks) for years, no issues.
 
You can also use something like this to get access to some of the zerksView attachment 3226961
I use something similar, although mine doesn't have the spring bit; it just screws on in place of the typical snap-on tip. Works great, especially on CV joints.
 
These mini grease guns with the needle fitting can be operated with one hand. Life-changing.

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