Ed's 77 Terex 72-41

[sawmilleng]

I looked back on the thread- Nige said on Jul 23 that the cylinder groups were either 6J4513 or 6J4515, the difference being the stroke. Apparently, this application is the longer stroke, but which part no. is the longer stroke is not clear.

Jon.

 

[kshansen]

Best I can find right now is specs for the 6J4515 cylinders.

 

[oarwhat]

I've never had a torque wrench that large. Whenever we did a cylinder on our equipment it was red loctite and get it as tight as possible with whatever we had. We didn't do many of them but none ever came apart. This is an old loader he's working on and not used everyday so I think it would be just fine.

 

[kshansen]

I've never had a torque wrench that large. Whenever we did a cylinder on our equipment it was red loctite and get it as tight as possible with whatever we had. We didn't do many of them but none ever came apart. This is an old loader he's working on and not used everyday so I think it would be just fine.

That is probably true but we did torque the nuts on the cylinders we did 90% of the time. Originally we just had 4:! torque multipliers so for the 1600 foot pound needed to use a large 3/4 inch torque wrench and get up to 400 Lb/Ft. Then we inherited from another part of the company a 16:1 multiplier that included a back stop system so now 1600Lb/Ft was even easier needing only a little 1/2 torque wrench!

Biggest trick was holding the ram while applying the torque. Once we had the 16:1 I came up with the idea of drilling a hole in the welders bench, it had something like a two inch thick top, Then using a 30 ton OTC twin cylinder ram we put the rod on the bench with a spacer under the pin end and used 30 ton ram to clamp it solid to the table. Table acted as a stop for the reaction arm of the multiplier and then it was a simple one hand job to work the torque wrench up to 1600 Lb/Ft

If ram was too long for table just let the nut end stick out the end and use a jackstand to support the end of ram and another to act as the reaction arm support. Besides the weight of the table it always had a couple tons of crap on the lower shelf so it never moved!

 

[kshansen]

Best I can find right now is specs for the 6J4515 cylinders.View attachment 227202

Did a little more digging and hit somewhat of a road block. Going back through this thread I see from the part number I see of 5J9884 that this piston and ram are of the tapered type. The spec's I found are for an updated design with a straight shaft and straight bore in the piston so now I'm not sure if the torques I posted in that chart are correct and so far have not been able to find a spec. for the tapered version.

 

[sawmilleng]

Gents, I'm not trying to pee in anyone's cornflakes here. If I offended anyone, I am sorry.

All I am saying is that there is a recommended torque for cylinder rod pistons and it is very high for a reason. This reason does not apply in this application of grapple forks because all the cylinder has to do when retracting is to lift the grapple forks open. It will rarely see any significant retraction loads.
So all the original poster needs to do is to know he should do his best to tighten the piston nut as tight as possible with the equipment he has. Loctite is great; a new nylock nut would be helpful, too.

Jon.

 

[mountainguyed67]

a new nylock nut would be helpful, too.

Ordered.

 

[mountainguyed67]

Is there a part number in the Detroit book for that holdown?

 

[mountainguyed67]

So all the original poster needs to do is to know he should do his best to tighten the piston nut as tight as possible with the equipment he has. Loctite is great; a new nylock nut would be helpful, too.

I used a 3/4 impact on the first cylinder, and blue Locktite.

 

[mountainguyed67]

I got a control handle for the dump lever, to work the log forks. The threads I needed wasn’t an option, so I drilled it out and tapped it. I have a jam nut ordered. Next time up I need to figure out what I need to build to mount the diverter valve. There’s nothing convenient to bolt it to, and can’t really get in there to drill holes. Might end up making a bracket I can weld to the machine.

 

[mountainguyed67]

I considered letting the diverter valve hang off a fitting like on my log splitter, I have someone telling me not to do that.

 

[kshansen]

Gents, I'm not trying to pee in anyone's cornflakes here. If I offended anyone, I am sorry.

All I am saying is that there is a recommended torque for cylinder rod pistons and it is very high for a reason. This reason does not apply in this application of grapple forks because all the cylinder has to do when retracting is to lift the grapple forks open. It will rarely see any significant retraction loads.
So all the original poster needs to do is to know he should do his best to tighten the piston nut as tight as possible with the equipment he has. Loctite is great; a new nylock nut would be helpful, too.

Jon.

Jon, no problem I actually prefer Cheerios!

And for this application I agree if things are cleaned of oil so loctite can get a good bond and as tight as the 3/4 inch impact can get it should be more than enough. I'm probably a bit on the fussy side and can get carried away trying to be exact on things like this. It's more of the thrill of the search for the information than anything else!

Might be a different story if we were talking about the nut that holds the piston to the steering ram on an off highway truck where a failure cold have major repercussions. Or the swing gear bearing on CraneOperators rig!

 

[mountainguyed67]

And for this application I agree if things are cleaned of oil so loctite can get a good bond and as tight as the 3/4 inch impact can get it should be more than enough.

I cleaned the threads all the way around with the wire wheel on a bench grinder, then blew them off with compressed air. I cleaned the nut threads with a wire brush that looks like a bottle brush, in a drill press. Then blew them off. And this was after pressure washing them.

 

[mountainguyed67]

Here’s what I’m going to use to control the grapple.

 

[6-110]

I had two 72-61 loaders with the logger package. They originally had air over hydraulic controls for the third valve which is the grapple. This was terribly erratic and destroyed grapple cylinders. I changed to morse remote cables like the other two functions and it was smooth to operate and easier on grapple cylinders.

 

[mountainguyed67]

I had two 72-61 loaders with the logger package. They originally had air over hydraulic controls for the third valve which is the grapple. This was terribly erratic and destroyed grapple cylinders. I changed to morse remote cables like the other two functions and it was smooth to operate and easier on grapple cylinders.

Something like this?


How well do you think it’ll work the way I’m setting it up?

 

[sawmilleng]

MG,
For my 2cents worth, you might find the control cable setup a little nicer, since you can feather the valve a little for speed control. The solenoid control is full on/full off. The only way you could get a little speed control with the solenoid is to use a flow control valve that will fix the speed-- you could probably use 2 valves, one to control the open and the other control the close speeds.

My vote would be for the simple--cable control manual valve.

On the valve mounting, don't hang it off the piping. Vibration or a tree branch will wipe it off-eventually. Mount it solidly with bolts and a welded plate mounting bracket

I noticed that your grapple forks are what I call "US" style, where each grapple fork is separate. I'm familiar with "Canadian" style grapples where both sides are connected together so they close as a unit. Do you need to use a flow divider to make the forks move evenly or does one close onto a log with the second one following when the first one bottoms out? I've attached a photo of a "Canadian" log grapple.

Jon.

 

[6-110]

The machines had two manual levers with morse cables like you are showing ,I built a third lever and used a morse cable on it also. I assume your system will not be graduated and the function will be fast and very rough. Cylinders start to internally by-pass and grapple will not stay open or closed. We even broke the eye off the end of the cylinder rod.

 

[mountainguyed67]

My vote would be for the simple--cable control manual valve.

The machines had two manual levers with morse cables like you are showing ,I built a third lever and used a morse cable on it also. I assume your system will not be graduated and the function will be fast and very rough. Cylinders start to internally by-pass and grapple will not stay open or closed. We even broke the eye off the end of the cylinder rod.

Where were you guys before I bought that valve?

 

[mountainguyed67]

I noticed that your grapple forks are what I call "US" style, where each grapple fork is separate. I'm familiar with "Canadian" style grapples where both sides are connected together so they close as a unit.

I know of at least one U.S. company that makes the style you pictured, maybe in Georgia. No idea who originated that style though.