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Possible to Grease Sealed U Joint?

YoshiMoshi3

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Is it possible to add grease to a sealed u joints without a zerk fitting installed from the factory? If so how? Is it possible to add a zerk? Can I puncture the oil seal with a grease needle and add grease, or would that not do much?
 
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Mr.N

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Yes, I do it all the time.
Take the cap off and add grease, just careful how much. Also be very careful you don't drop a bearing.
 

Mr.N

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I only use Spicer/Dana or high-end u-joints. You can get a lot of Spicer u-joint with a grease fitting on the cap, just usually more a custom order.
Don't puncture the seal, that will make an opening for grease to get out and/or dirt in.
Drilling a hole for a zirk fitting seems like a lot of work, I would have this be a last option.

Are the u-joints going bad because of lack or grease or breaking? Do you mark the caps to see if they spin? (A spinning cap is not good sign). What brand do you run?
 

Shoreline_

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I would not drill a hole to grease non serviceable bearings or ball joints. It's not just the manufacturer trying to screw you or them trying to save a penny on a zerk fitting.
 

Steve_P

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Some are staked in place and can't be removed. So, unless you puncture the boot, which I wouldn't do, you're out of luck.
 

john.k

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The sealed bearings are claimed to use a special grease,which fails if ordinary grease is added .......it appears this is true with universals ,as adding grease to new unis causes them to fail at much shorter milage than OEM specs............The driveshaft in my 4x2 pickup is nearly 20 years old,and I been wondering about it...........maybe I should replace the unis instead...............the OEM spare is a whole new shaft at around $4K .
 

Mr.N

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Some are staked in place and can't be removed. So, unless you puncture the boot, which I wouldn't do, you're out of luck.
Can you expand more on a staked in place? Are you talking about adding grease while the u-joint is installed and not removing it? Yeah that would not be advised.
I am talking about installing grease before you replace and install a new u-joint. If you are deep into checking the u-joint it's cheap insurance to replace it rather than to reuse the used one.
 

Mr.N

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The sealed bearings are claimed to use a special grease,which fails if ordinary grease is added .......it appears this is true with universals ,as adding grease to new unis causes them to fail at much shorter milage than OEM specs............The driveshaft in my 4x2 pickup is nearly 20 years old,and I been wondering about it...........maybe I should replace the unis instead...............the OEM spare is a whole new shaft at around $4K .
Can you share where you found this information?

Back in the day the Spicer Expert site had a lot of pictures of different failures of u-joint... I kind of made a lot of post on Pirate4x4 about this stuff... never heard of not using 'Special Grease' as a failure point.
 

john.k

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This would be the OEM grease from the packet .........i dont know what it is ........Spicer would be the people to ask..........what I do know is my unis are pushing 20 years old ......and while the joints arent loose ,I sure dont want to drop a tail shaft.
 
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john.k

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Id think cracked seals would be a sure cause for replacement .........red stain coming out of the seals another bad sign........this is assuming the uni is still free and tight...............I know in trucks with greasable unis ,the surplus grease would be stained brown in a week sometimes.....On my IH 130 service truck ,I had to replace the tailshaft spline several times,assumed because it was straight line ........the unis were never replaced ,just greased once a week...........and I drove that truck for a lot of years ,and a lot of miles.
 

dvblanch

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Think would be easy to just move the joint around by hand. If it is smooth and no signs of rust around caps or squeaking in operation just leave well enough alone. Disassembling to grease can be done but is same work as installing new joints. Driveshaft shop I use swears by Spicer nongreaseable joints and I have great service from them
 

rockbaron1

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Can you share where you found this information?

Back in the day the Spicer Expert site had a lot of pictures of different failures of u-joint... I kind of made a lot of post on Pirate4x4 about this stuff... never heard of not using 'Special Grease' as a failure point.

I saw a post of yours the other day on here and was wondering if you were the same Mr. N from pirate4x4. Anyway I think sealed u-joints come with silicon based grease, at least that’s what it seems like when I take them apart, but I don’t have any data to back that up. The issue would arise if you try to mix silicone based grease with lithium or petroleum based grease. At lease that’s my experience.
 

john.k

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One time I got a call from a car repair shop to put a clutch and Roadranger gearbox back in a truck .........they couldnt do it ,and the truck owner was threatening them with violence ...............when I got to the car shop,they had spread all the rollers and caps from the universals all over the dirty concrete floor ,some were in cracks in the floor..............said they didnt quote for new unis ,and the old ones had to go back..............you can be sure I got my $500 cash up front from this bunch of hillbillies.
 

rust in the eye

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Very little if any grease could be effectively injected past the now ruined with a grease needle seal. You can re-grease by dismantling them which usually involves pressing at least one side out.
For the labor involved and the low cost of (automotive anyway) U-joints it doesn't seem worth the effort to dismantle, clean, grease and re-install an old one.
Typically those without a Zirk are solid ones used in HD aplications. You can always substitute a greaseable one but with some concession to strength.
 

Mr.N

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I saw a post of yours the other day on here and was wondering if you were the same Mr. N from pirate4x4. Anyway I think sealed u-joints come with silicon based grease, at least that’s what it seems like when I take them apart, but I don’t have any data to back that up. The issue would arise if you try to mix silicone based grease with lithium or petroleum based grease. At lease that’s my experience.
Yeap same one. When they crashed and changed the passwords I lost my account, just never went back as I started to hit the trail a lot more.

I responded as this is a great response. Mixing types of grease and how they are designed to be used is a great area of discussion. I forget why I do it, but I do use the synthetic grease but feel my u-joints are way different application than anything that sees highway speeds.
 

Mr.N

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At what mileage or age do people find universal joints in trouble?
This is more driven by environment/maintenance and/or usage/abuse than life expectancy.
Grab both sides and shake hard, if the yokes don't move together dig further into it to see if bad.
 

Torque&Recoil

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NE Ohio
At what mileage or age do people find universal joints in trouble?
My old Jeep Cherokee. About 60k miles before failure of front axle u-joints.

More recently, wife's BMW X-3. About 100k miles for the rear driveshaft u-joints. Took out the transfer case bearing when the driveshaft u-joint quit articulating. What a PITA...
 

xjfish

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At what mileage or age do people find universal joints in trouble?
50-400k. Varies a lot by application and environment. Usually fail from drying out or water intrusion.

My Chevy Tahoe still has 2 out of 4 original u-joints at 300k (injection molded retainers)
 

Sumboodie

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I saw a post of yours the other day on here and was wondering if you were the same Mr. N from pirate4x4. Anyway I think sealed u-joints come with silicon based grease, at least that’s what it seems like when I take them apart, but I don’t have any data to back that up. The issue would arise if you try to mix silicone based grease with lithium or petroleum based
Yeap same one. When they crashed and changed the passwords I lost my account, just never went back as I started to hit the trail a lot more.

I responded as this is a great response. Mixing types of grease and how they are designed to be used is a great area of discussion. I forget why I do it, but I do use the synthetic grease but feel my u-joints are way different application than anything that sees

It's irate4x4.com now
 

Milton Shaw

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The only U joint I had fail and leave me stranded was in high school 1965 or so. The car was a 56 Ford wagon and my dad had put seat belts in it for all seats. One night I was sent to pick up 100 lbs of ice and that on the tailgate was enough to sag the back very badly. The bolts for two of the seat belts were in the top of the driveshaft hump and just the right place to break off the U joint retaining bolts at the pinion bearing and the whole drive shaft fell out in the parking lot.
 

Steve_P

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Can you expand more on a staked in place? Are you talking about adding grease while the u-joint is installed and not removing it? Yeah that would not be advised.
I am talking about installing grease before you replace and install a new u-joint. If you are deep into checking the u-joint it's cheap insurance to replace it rather than to reuse the used one.

The bores on the driveshaft are staked to lock the u-joint in place instead of using a retaining ring. When a u-joint goes bad you buy an expensive driveshaft assembly. I can't remember what brand(s) use this, newer vehicles, but I've seen it on another forum.
 
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