Hydraulic Top Link came apart... Failed!

teg · Aug 16, 2016

Midniteoyl said:
Goes on wet, tighten, let dry..

Thanks... Will do.

Another (possibly stupid) question... Could I have noticed "slop" in the top link (assuming I was looking for it) before the nut totally unscrewed???

I would also assume that I could not have just grabbed the top link and try and move it in and out by hand... I would have to watch picking up or dropping an implement to (maybe) see slop??? ...and the slop would only be less than 3/4" (thickness of the nut). Maybe not....

hawkeye08 · Aug 16, 2016

I'm thinking it was never completely assembled correctly, either new or after previous rebuild. Use this project to get yourself a nice 3/4" impact from HF (if you have the air compressor to drive it).

teg · Aug 16, 2016

You can see thread imprints in the nylon but I guess not tight enough....

There is a shop at the research station that I'll be at tomorrow, they work on super big stuff... which reminds me, I need to put it in the truck and bring it to them to put the final touch on it. Their compressor is about the size of my truck.

teg · Sep 4, 2016

Got it back together with threadlocker and a pretty good size impact wrench.

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Threepoint · Sep 4, 2016

Well done. :thumbsup: Bet it's a satisfying feeling. Look forward to an update after you've used it awhile.

BukitCase · Sep 4, 2016

If you got the gland off that easy (and we KNOW the piston nut wasn't on very good) then the cylinder likely wasn't assembled correctly in the FIRST place - the way you put it back together should be fine, but just as a reference -

My old Case backhoe has several cylinders that are about half again as big as typical toplink cylinders for Cat 1 tractors (I have 2 of those also, both with hyd toplinks) - the rod nut for the Case cylinders calls for 450 ft lbs torque (fine thread on 1-1/2" rod) and my glands have holes in the end like yours - I've snapped off 5/16" bolts loctited into 3/8" flat bar trying to get those glands off, couple I had to get close to cherry red with a rosebud before they'd move, even with a 3' pipe wrench and a cheater bar.

Granted, the ones on my hoe are bigger and have likely been in place for decades, but my point is these suckers need to be TIGHT - and again, it sounds like you're good to go as you did it; the ONLY time that rod nut should come off is AFTER the rest of the cylinder is dis-assembled, and after spending the last 35 years of my working life in heavy industrial maintenance I would NEVER trust a NyLock nut in that environment (running in oil) WITHOUT doing what you did with thread locker. Good job... Steve

Threepoint · Sep 4, 2016

BukitCase said:
[snip]after spending the last 35 years of my working life in heavy industrial maintenance I would NEVER trust a NyLock nut in that environment (running in oil) WITHOUT doing what you did with thread locker. Good job... Steve

Steve, hmm. I'd never thought about the Nylock-style nut running in oil issue.

Is it a problem with the polymer breaking down? For that matter, is the Nylock-style commonly used inside the cylinders? Also wondering about differences in durability of generic nylock polymer, given different vendor and quality control.

teg · Sep 4, 2016

Nylock-style nut didn't seem to have broken down when I was putting it back together but it also didn't "hold" the nut in place either... there are lots of forces on this nut. It looked like it was put on with something with a biting jaw... definitely not a socket.
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My concern is, how many others are just about to come un-bolted???

BukitCase · Sep 4, 2016

Not holding (bathed in oil) would be my first concern, but these days everything but a loaf of bread may come from china, so who KNOWS what their slip-shod manufacturing thinks is OK to use 'cause it's cheaper than what we EXPECT to see for materials? Plus, if the item you USED to buy had 12 ounces of material per piece, they'll try to get by with 8 oz...

Also, I've rebuilt about 8 of the 12 cylinders on my Case and a couple on my 50' manlift, and NEVER saw a Nylock used internally; just fine threads (higher torque spec) and LOTS of torque.

When somebody has "knuckle-dragged" a nut like that nylock I won't put it back together til I find a virgin replacement - first time you do a job, it can be interesting/informative - the third or fourth "do-over", not so much...