Thanks, I think I will! :grin2:
...explain why all trucks concerned with reliability...have zerks on any and all Ujoints?
Well, you're making some assumptions that aren't valid. I'm concerned with reliability on my truck, and it DOESN'T have Zerks on the U-joints, so there's ONE.
And the fact that sealed u-joints are made proves that you're wrong about "any and all".
...the soft rubber lets the grease ooze out without damage...
Grease certainly oozes out when pressure builds up inside, but that doesn't mean there's no damage. I've seen undamaged seals lift off the u-joint caps when some gorilla pumps too fast (and yes, I was the gorilla at least once). And after the grease stops oozing, it's still there holding the seal away from the steel, whick can allow contamination back in to do damage to the bearings.
Oh, thanks for the tip - I've never greased a u-joint before. :icon_rolleyes:
The mfgrs aren't completely stupid.
Right - they're smart enough to sell whatever people will buy. Including stupid people. That's why fuel line magnets, hair-dryer superchargers, and cardboard pizza are for sale. So if there's a market for greasable u-joints, you can bet that someone is smart enough to sell them. But that's not proof that they're better. For many years after pneumatic tires came out, heavy truck mechanics still argued that solid-rubber tires were superior. No surprise that the same thing is happening with this little improvement.
Don't know your in shop experience, but myself and any other mechanic wipes off all zerks before hitting them with a grease gun...
It's like you're not reading what I'm writing - wiping a Zerk
doesn't remove the dirt that gets pumped inside.
As to my in-shop experience:
I've worked in about 20 (including a few dealerships), and of all the times I've noticed a mechanic greasing a Zerk, I've NEVER seen one wipe it off first. Not that it would have helped.
...explain why loaders, graders, all trucks above pickup size have drilled U-joints from the factory?
If this discussion forum was about loaders & graders, your point would be valid. The grease journal drilled into those u-joints is the same size as the one in a light truck's. But the trunnion is 2x-100x the size, which makes the drilling vastly less-significant to the u-joint's strength. And since it's not nearly as practical to remove & grease those u-joints as it is on a light truck, those u-joints MUST be greasable.
But since this forum is only about light trucks, that's all irrelevant.
...the first thing that lets go under a severe shock load is not a drilled U-joint, the driveshaft twists up like a pretzel and breaks.
Not in my experience, and I've been working on vehicles for a few decades. Primarily light trucks & passenger vehicles, like what this forum is about. If you're still talking about heavy equipment or you've jumped over to supercharged competition tractors or home-built rock buggies, then your claims are still irrelevant.
In a light truck, the stock u-joint is DESIGNED to be weaker than the stock driveshaft for exactly the reason you described.
I'd bet cheapest bid would be the reason Ford and Chevy don't come with greaseable joints...
I'd believe that about GM & Dodge - they clearly don't know how to run their businesses. But Ford does, and they don't pinch a penny on the assembly line just to pay out a million dollars in warranty claims & recalls. Sealed u-joints (which ARE greasable) are stronger, require less maintenance, and last longer.
Has ANYONE ever seen a u-joint that wasn't put in one helluva bind break???
Right there:
It's a crappy picture, and an even-crappier u-joint. But it had never been bound up or shock-loaded, and it just broke apart.
...just maybe, the joint cross might be a bit thicker to compensate for the "weakness" caused by the grease passages?
3 problems with that guess:
1) Most aftermarket sealed u-joints use the same trunnion casting as the drilled ones;
2) The "weakness" caused by drilling is in the ends of the trunnion where the bearings & caps go. So to make the trunnion thicker there and still have the u-joint fit into the same yoke, either the needle bearings would have to be smaller, or the caps thinner;
3) There's still the problem of the wedge-effect of the tapered pipe threads on the Zerk splitting the trunnion where the posts come together.
...I never heard of stronger ungreaseable joints from any guys actually in the industry...
Then you must not be paying attention.
1) No one is talking about "ungreasable" u-joints; sealed u-joints ARE greasable during installation, and for service by disassembly;
2) That Ford TSB I posted earlier was first published 20 years ago - why haven't you read it by now? Here's another source, just so you know I didn't come up with it on my own:
http://www.revbase.com/BBBMotor/TSb/DownloadPdf?id=43046
Look up any other TSB you like:
Search Technical Service Bulletins
3) I'm a guy actually in the industry, so you can never make that claim again.
...only from "armchair engineers" on various forums.
So where did YOU study engineering? Or are you talking about yourself armchairing on this forum?
Unproven theory beats experience every time...
You're a perfect example of that! :thumbsup: