Questions on greasing the universal joints.

My forward and rearward universal joints have grease fittings on them and I thought that it would be a good idea to squirt some grease into them. This was my first time at ever trying to do this. The picture shows the rear U-joint and the bright dot in the center is the grease fitting.

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I bough this mini-grease gun at Sears for $6.23 and it came with a 3-oz tube of lithium grease. I included my car keys in the photo to provide scale.

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I wiped the grease fittings clean, pushed the grease gun onto the fittings and gave them three squirts each. Here are my questions:

My grease gun did not "snap" onto the grease fitting, and I just pushed the grease gun against firmly the against fitting when I pumped the grease

Is that the way it is supposed to be done?

How am I supposed to know if any grease went into the fitting? I wiped some fresh grease from around the fittings afterwards, so some was being pumped out of the grease gun.

Note in the grease gun photo how the plunger is all the way it. The grease gun had initially squirted some grease when I loaded its cartridge and it seemed to pump grease when I did the rear U-joint. Then when I tried to grease the front U-joint it seemed like no grease was coming out. I put my thumb on the release and pushed the plunger and was surprised to see that it easily moved all the way forward. How could that happen? The grease didn't squirt out from behind the plunger. The grease cartridge had felt like it had some weight to it and that it had grease in it and it was was not empty. Does it take the first cartridge of grease just to "prime" a new grease gun? After the plunger went all the way forward the gun started pumping grease again and that was when I applied three pumps to the forward U-joint.

With most grease guns you will hear/feel a definite click when you push it on the zerk fitting. Sometimes it can be really hard to yank them off when you're done.

Also, you will usually see the old grease (if there's any left) ooze out somewhere. You should pump until you see your fresh grease come out and then wipe up the excess.

You should probably stock up on extra grease cartridges. I think they have a pretty good shelf life and if the brand of gun goes extinct, they may be difficult to find. Unless it's a really common size. Maybe the plunger didn't go forward because there's a little bump on the rod and a notch on the lid that engage. This keeps the rod from going forward when you remove the lid to add grease. Or an air pocket??

Grease does not compress - so if you pulled the trigger and grease is coming out of the tip, it came out of the tip as well when attached to a fitting. It had to have, unless you hit a pocket of air on the grease gun end of things. You'd have felt that as an easy pull of the trigger. Generally, when grease guns are primed - they stay that way until all the grease that can be pumped out does get pumped out.

True what Kenny says too about squeezing until grease comes out somewhere, but that isn't always going to be the case. Some ball-joint "boots" only fill up and don't ooze. And if they do, the boot is often ruptured. U-joints you will want to pump until grease comes out from a couple seals - if not all 4. This is considered also a flush of old grease - and is a good thing.

As for the push and click, I've seen these mini guys only have the push-hold tip seal. You can look at the end of the tip and if it is very shallow and has a rubber seal near the end of it - that's the type. A push/click style will have some depth to the tip and 3 or 4 little metal "claws" that retract when you press them on and are supposed to retract to remove them. Some grease guns don't relax the pump the way they should and hold full back-pressure on the hose and tip and they won't [easily] come off. You have to yank and twist to get air between the hose the grease fitting to let the claws relax their hold.

Hello, Kenny and Roger.

Thanks for the explanation. I guess that I just have a cheapie grease gun that did not come with much grease.

Roger said: "A push/click style will have some depth to the tip and 3 or 4 little metal "claws" that retract when you press them."

That sounds like what I need. The next time I visit an auto-parts store, or maybe a hardware store, I'll see if they have a grease gun tip of that style that will fit my grease gun.

I did quick look on e-bay and saw this for $8:
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Description: "This is a brand new heavy duty 4-jaw hydraulic grease gun coupler. This tip has a neoprene core which lasts longer than standard plastic in most tips. Another benefit of this coupler is that it has 4 jaws instead of the standard 3 making it grip the grease fitting much better so it does not pop off while greasing.

Most importantly this grease tip has a pressure release valve to release pressure that occurs while greasing, especially with an electric grease gun. Instead of fighting the pressure and possibly breaking the fitting or the tip you simply turn the end of the coupler one turn and it allows air through to release the pressure.

Last of all, this product is NOT MADE IN CHINA. It is a heavy duty German Coupler and ships from the US." (Poor China)

Thanks, Dennis.

PS: Over the past couple of weeks I drove the The Wonder Falcon to work for eight consecutive days (before it started raining again). That is a new personal record!