I am putting new seals in and apparently I need to get the bottom nut to 600 ft lb. I do not have that kind of torque wrench. How do most people achieve this? Thanks.
One way would be to mark the position of the nut before you remove it, then re-tighten it back to the same position. I have no idea if the BC repair requires Loctite on the threads but irrespective you could use it any way, just to be sure. A torque of 600ft.lbs equates to 150 pounds on a 4-foot long bar which is achievable. (Be sure to use a black impact socket if you are going to be bouncing on the end of the bar, just in case.) The photos in this thread might give you a bit of an idea, but remember the nut in the photos was tightened to over 5,000ft.lbs not 600....!! HeavyEquipmentForums
Not actually bouncing on the end of the bar, I might add. If you weigh 200 lbs then you need to just stand on the end 3 feet from the pivot point. With the bar out parallel to the ground. It is actually a very accurate method of getting proper torque. Bouncing on it can get you quite a bit more torque than length x weight would figure up to.
I was thinking that the bouncing might be required to loosen the nut, not for tightening it, especially if it had Loctite applied previously. Sorry I should have made that clear.
600 ft pounds for a gland nut on a bucket cylinder ?? I have yet to run across any bobcat cylinder i could nut bust the gland nut loose with a 1\2 impact. The last few I have done on bucket cylinders I have used my cordless impact with no issues. I have never torqued a gland nut on any smaller cylinder. Bobcat/backhoe etc. Only time I get torque critical is on anything ariel. I just hit it with my impact and stick the rod back in. 20 plus years I've never had a gland nut back off. Especially on something like a bucket. You would have to get the highest torque you could from a torque wrench then start counting turns like was mentioned above.. Me personally I would tighten it as tight as you could... Stick it back in there and go on with it with out a second thought about it.. But hey that's just me
The nut on the bottom of the rod is called a gland nut? I know the top of the cylinder required a gland wrench, which I had to buy. I was not aware that the nut at the bottom is referred to as a gland nut as well. It sounds like the torque may be less than 600 anyway. The lift cylinder on my s150 calls for 600ft lb and the tilt plate only calls for 100 ft lb. So, I think the combo bucket torque is probably less than 600 ft lb. I am trying to find out for sure. I cannot seem to find a manual for bobcat buckets yet.
Well no wrong nomenclature on my end. Piston nut. Rod end nut what ever your particular term that you choose to use. Just put some lock tight on it and hit with the the impact. I don't even use lock tight personally. I just hammer it down till my impact wont do anymore then put it back together and send it back to work.. Here again that's just me. I do understand some folks are sticklers for detials.
I may be doing exactly what you suggested, if I cannot find the specific torque value. The rod is 1.25 inch and the nut on the end is a 1 1/8 socket or possibly 28 mm.
When I resealed the boom cylinders on my skid the book called for some unreasonably high torque value on the gland nuts as well. Wanting to do it right I went out of my way to purchase a torque multiplier, with which I proceed to wring the threads right off one of the rods. After an expensive trip to the machine shop I just put the nuts on good and tight and called it a day. No problems since then.
Well, I just took the nut off and all I had to do was turn it with a regular ratchet. Not only that, I put almost no torque through it. It was "snugged" at best. Either that, or it loosened up. It took zero effort to remove the nut.
I have to give props to Summit Bobcat in Walden NY. They read the manual over the phone for me. 300ft lb is what the manual calls for and speaks nothing of thread sealant. I have a torque wrench that goes to 250ft lb.
That sounds more like it..
It might even be less than that. The dealer read me the manual, but I am not so sure it was the correct manual. ugh. I found a Bobcat combo bucket manual on line. That bucket uses the same size rod and bore cylinder and that one has a gland nut torque of 180ft lb. So..... I emailed Bobcat. If I don't hear back, it will get torqued to 180ft lb. I used zero torque to remove it. Most important thing is not breaking it.
Is thread locker usually used in this application and if so, which one? Thanks.
Not normally used but it wont hurt anything. You just have to let it cure before putting it back together and its submerged it in fluid. I would use blue loctite if you want to use some
I did a tilt cylinder (T140) a couple of months ago and it Threadlock Red on the threads. I broke two vises trying to torque the first to 500+ ftlbs. Finally took it to good hydraulic shop downtown to torque the nut. He said he always uses Threadlock Red and just torques until the impact wrench stops. He told me that on REALLY big piston nuts (dozers, etc)... he uses a torch to melt the Threadlock first... said to just heat them until you hear it sizzle, then hit with the impact wrench. I did the lift cylinders later and they both had Threadlock red, too. Much easier to torque (200 ftlbs +/-) I'm new to this and was terrified the nut might come off and damage the cylinder, so I used red as well.