Ok,Bearing went to pieces in a single sheave block.......I have my own Ideas why but need some unbiased opinion. This uses a sealed bearing and the inside race is rusty. Using two blocks at the time to set precast wall panels. Said they heard a loud bang and and shut stuff down......I grabbed another block and made a mad dash to the job.Just these two pictures cuz they needed the rig in the air. Lost 50 feet of cable due to damage from this.Non spin cable WILL NOT withstand ANY abuse. I wish it was half as tough as the old IWRC.
Can't say for certain, but I'm thinking that giving that sheave a spin before reeving would have indicated something crunchy was going on.
It was quiet,no drag
Looks like it was built without any lube in the sealed bearing. That rusty race is a good indicator. was this a McKissick/Crosby Block or a chinese copy?
Looks like it failed due to lack of lube in the bearing Tiny.What I dont like about the block is it looks like a 3 sheave block with only 1 sheave.Had it had all 3 sheaves in it even though the bearing failed on the center sheave ,the cable would have stayed put in the sheave groove.That's my best idea Mr Tiny.
Does that block have a side mount third part dead end on it .. Notably..alot of the European single sheave block's have the dead end on top in the center of the block The reason I ask is ..often the block doesn't hang true when unloaded..Eventually like a leaking faucet will fill a sink ..the up and down will wear the seal out ..remember when you first heard that the weight of a dime will wear out a clutch.... In the past ..Ive looked at sealed sheave bearing's for oil creep ...there's always a little .. clean it of...give it a week or so ..it shouldn't come back that fast..indication the seals are going and the few grams of lube is disappearing..when there's no creep there's no lubrication....That's on and old block .. on a new one..Id expect it to stop after a bit until the seals are seated..when it starts again keep mental notes..and not only the spin..but lateral side to side play..Play in a sheave is crucial ..the sheave manufacturer should be able to provide details on whats acceptable in this area.. Like everything else tiny..it has a life expectancy..We had a brand new 210Grove with a seized sheave in the swing away..
This block was a single sheave from the factory.That extra width lets you leave the Becket on the cable. This is a Demag and it is a center mount 3 part tab. Another thing we have going on is these blocks are hauled flat on the trailers which is my belief promotes water to set on the seals and seep in. For the record I absolutely Hate sealed bearings , The old hands have seen the older stuff last years because when you pumped grease in to a bearing the water would be pushed out.
nothing like EP1 or 2 to keep it going...
Looks like grease worms ate all the grease out. Those buggers are nasty this time of year.
. From the pictures provided it looks like the load cable was pulling sideways and the hook being in the center of the block the load put stress on the side of the sheave and cable trying equalize the line up with the downward force slipped off the side, and caused the bend in the sheave trying to line up for in line alignment. The bang that was heard was the cable slipping off to a smaller diameter which could have broke the load line. Pulling off center of block will wear out bearings fast. The cable made its way all the way to the opposite side trying to line up. Was the bearings in the sheave, that was damage, froze up compleatly or would it still turn over the incident ? .