Need help with a stubborn NUT!!

[Dusty]

I am trying to assemble my 4 post car lift and have run into a problem. The hydraulic cylinder is threaded and there is a locking nut that needs to be screwed onto it. The shaft doesn't have any flats to grab hold of, and when I attempt to put the nut on with the impact wrench, it will only go on about 1/2". I have backed it off to see if there was any damage to the threads, but the threads are perfect. I tried to lubricate the threads with anti seize, but that only helped slightly. Any suggestions, short of grabbing the shaft with a pipe wrench? The nut takes a 1 7/16" socket. thanks Dusty

 

[goaliedad]

I can see why you wouldn't want to grab the shaft with a pipe wrench- can you safely put pressure on the cylinder, then tighten the nut? maybe the pressure will keep the shaft from turning?

good luck

 

[Casco1]

if you're worried about damaging the shaft. I would use a strap wrench. Plumbers use them to work with chrome pipe. Sears has some in the under $20 range. I have a heavier duty Rigid brand, it's suprising how handy it is for holding anything with an odd shape.

 

[3RRL]

Can you get it to a mounted vise? Clamp shaft with 2 pieces of leather of plywood.

 

[KubotainNH]

Looks to me to be a nylon lock nut. Also looks like it stops when it hits the nylon part. If you can spin it easily on until it hits the nylon then use the pipe. It will get easier after it gets through the nylon. It could be a different thread size but then it wouldn't spin on as far as the picture shows. Maybe you could get a pair of nuts the same thread size and tighten them against each other so you have a good point to lock onto the shaft. BTW, unless you have a high end impact wrench (lotsa ft lbs) it probably will bot tighten that size/type nut.

 

[Ifixcars]

Some lock nuts are very, very hard to run on. You may have one of the tough ones there, it's hard to tell even though your picture is good quality. I have had some bigger all steel lock nuts give me trouble on a shaft/bolt that did not spin on me. If you only have the one to do, and you don't want to mark it at all, you may have to pre use the lock nut on a bolt you can hold still. To kinda loosen the lock nut up some. Maybe use loctite with the loosened nut. I know you really shouldn't re use a lock nut but sometimes you gotta do what you gotta do. You might switch to a less aggressive type lock nut, like with a nylock insert instead of the all steel type, depending on the application. Otherwise the other posts that suggest a non marring hold are worth a shot. If they don't work, you either have to get a grip with teeth on your nice new piece, in a spot that won't affect the operation of the unit or try the above.

 

[cp1969]

If you use any type of pipe wrench, vise, etc, you will damage the surface of the shaft. If you have access to machine tools, you can make a pair of brass blocks that have the size of the shaft bored through them where the blocks meet, then use bolts to sandwich the blocks on to the shaft and hold it with a big crescent or pipe wrench.

If you can get your hands on a non-locking nut of the same size and see if it goes on. If not, you might need to return the cylinder to whomever you bought it from.

 

[ronjhall]

Is there enough room for 2 standard nuts with a lock washer between them. This should give you the same locking power of the Nylock nut.

 

[Dusty]

I have already tried the the strap wrench idea, and that didn't work. This has to be done under the runway of the lift, so the vise idea is out. I like the brass block idea, but being a polished chrome shaft, I don't know if it will have enough friction to tighten. There is no question that the nut is correct for the shaft, but I have a feeling that the manufacturer had intended for it to have a one way situation. This nut is the only thing that holds the cables to the cylinder, so they don't want to gamble that it might come loose. I believe that they intended for it to be an interference fit, but it is jut too tight. I have a 1/2" Snap-On impact, but I can try another that is in the tool box, in case the old one is getting tired, but I don't think so. Now that I got the nut on that far, it also doesn't want to back off. Thanks for the help so far.
Dusty

 

[RCT]

Try hitting it with a torch first. If you put ice cubes up against the threaded rod for about 30 seconds and then hit the nut with a torch the difference in temps will speed the process. I had to do that one time swapping a CV joint out of a Toyota after I had hit the collar for 30 minutes. I gave up on it for about 4 hours until I came up with this trick. It took all of about 10 seconds to get the sleeve out doing that. I have used it several times after that with good sucess. It wors best if you put the ice cubes in a large ziploc bag and drape them over the shaft.