Replacing the BLADE on a Motor Grader | John Deere 770GP
how you going guys Kurtis from Cutting Edge
engineering today's job we have a John Deere grader in to have its blade replaced this
is a John Deere 770 GP this is a mid-range size machine so there are smaller and there
are bigger this size machine are commonly found for doing roads and construction Works
around new building Estates and stuff like that they're not really a mining machine they
could use them on the haul roads to clean them up but they generally run much bigger
machines on a mine site and this grader does look new because it has just had a paint job
so the grader originally came in to have its blade skin replaced it also needed the bottom
guide on the back of the blade that the blade slides along replaced so the blade skin and
the blade guides are going to wear out sooner or later it is just the nature of the way
things work so even with the best operator and the best maintenance you will have to
replace them at some stage of the graders life after the grader arrived I did my inspection
of the machine and I noticed there was going to be a few other things that were going to
be a massive problem so I noticed that the blade skin is actually still in really good
condition it is still quite thick and it doesn't look like it needs to be replaced the blade
guide is worn out it's not the worst one I've ever seen but it does affect the ability for
the grader to do final trimming because of the way the blade sits into the cradle every
time the operator is to move it left to right the blade is essentially jumping up and down
as it's going over those worn areas so that does affect the way the grader can trim but
what I got around to the back of the blade I noticed there were two holes worn into the
original blade body itself and there was a big crack that runs from one side all the
way to the other where the blade guide mount gets welded onto and that's a serious problem
because that is the main blade structure completely worn away so if I was to try and remove the
blade skin and the guide while there was so much of the blade structure missing the chances
that it would pull out of shape and be unusable are just far too high after talking with the
owners we decided it wasn't worthwhile trying to repair it because of the issues we're going
to run into we're just going to replace it the owners of the machine were not aware on
how worn out the blade actually was because these machines can go for a 6 to 12 month
contract once this finished its last contract it went to the paint shop got its paint job
and then it came to us to have a few more repairs done to it most graders don't come
with wear skins on the blade structure itself this blade skin was put on the blade after
the damage was done so it was too little too late the customer has ordered in a new blade
it is not genuine it is aftermarket but it has everything on it it is basically a bolt-on
bolt-off system because this machine uses GPS to control how it grades we do have to
change over some of the GPS bracketry and fit them back onto the new blade so let's
get on to it while the blade is standing up everything is nice and easy to access so anything
that we need to take off the blade in order to fit to the new one I'm going to take it
off now first thing I'm going to take off is this GPS Mast because it is very expensive
and I don't want to hurt it what a beautiful day be about 32 degrees but nearly
50 percent humidity here not a cloud in the sky now with those off we can take the pin out
that holds the blade slide cylinder in place this could potentially be the hardest part
of this entire job because they can just lock themselves in place and they never come out so these pins always seem to lock themselves
in place they aren't greased they just run dry so what's happened here is the bush in
the end of the cylinder rod has grabbed a hold of the pin and it's probably rusted itself
in there and it's going to be a nightmare to remove what we're going to do now we're
going to get the oxy out here going to heat the end of the rod up and hopefully relieve
a bit of the pressure from the bush onto the pin and hopefully we'll be able to draw it out so that went really well even though I did
have to heat it and pull it out with a come along that went pretty good generally you've
got to either lance the pins out or you cut the bracket off the blade and then you deal
with the cylinder rod with the pin jammed in it later on but it's way too hot out here
today the cameras are overheating a lot we're having to stop doing what we're doing and
letting them cool down so rather than continuing to do that I'm going to make some room over
in the igloo although it's going to be a lack of room around the machine with the forklift
it's hopefully going to be a lot easier in the shade and a lot cooler for the cameras get it what's that what a good boy go get your chicken go find it [squeak squeak] so it's much nicer in the shade I made enough room that I can actually get
around the grader with the forklift what I've done is I've rolled the blade forward so I
can access the top clamps that push down onto the top guides what I'll do now is I'll block
the blade so it can't roll off and then I'll undo the top clamps and get them out of the
way now that we've got the old blade removed you
can really see how much wear and damage there is on the blade and the guide the guide is
very worn out in its working area it has a certain range that the operator will work
it within and now you can see how bad the blade is worn and the separation between the
original skin and the weld that holds on the guide that has separated pretty much the entire
length of the blade and it is extremely thin so it's supposed to be this thickness all
the way along the blade around the edges it's quite thick but through the center it's paper
thin [tappy tap tap] so the only thing that is holding this blade
together are the ends and the skin that someone's put on the front now that I've seen the extent
of the damage I'm really glad we're replacing the blade so what I'm going to do now is I'm going to
remove the old inserts that the blade guides work on so there's not a great deal of wear in the
guides that we've just taken off but there's no point putting a brand new blade with old
guide inserts so we're just going to change them out just rough castings right now that all that's done we can
get the new blade fitted this is a new blade made in the USA so it
is a really good quality probably the closest thing you'll find to a genuine part not like
some of the other stuff that's coming in from overseas and as you can see in here this one's
not made from paper [dong dong] so there's not really an easy way to fit grader blades you sort of just got to put them on the ground shuffle them in under the machine and then stand them up if you had an overhead crane or another guy on a forklift it would be a little bit
easier you can't really access in underneath the circles of the machine with anything so
it's just going to do what you got to do so that actually worked out pretty good the blade's sitting in position and it's nice and safe I've got a chain wrapped around the blade over the back of the cradle so it can't fall forward now we can put our top clamps on
and our new guides so the blade's now on we've got our top clamps
in place so that's secure enough I can now take it into the workshop I'm taking it over
there because I do have to refit the GPS bracket and I'm going to have to do some welding so
rather than do it out here in the wind we're going to take it in the shed now that I've tilted the blade all the way
forward I can now tighten up the clamps that hold in the top of the blade now I can refit the blade slide cylinder I
just need to straighten out the pin plate now with all that done I can wind down the bolts to put pressure on the inserts to keep the blade in alignment so it travels left and right nice and true I don't want to over tighten them because that would apply too much pressure to the
inserts if you apply too much pressure to those they will wear out very quickly so you'll
see me tighten them down until the bolts touch and then I back them off just a little bit
and then wind the jam nut down to lock them in place as the inserts wear out the operator
or a mechanic can adjust the bolts to wind the inserts down to take up any slack so now what I'm going to do I'm going to refit
the Trimble GPS pole it should be interesting because this blade is slightly different in
the way it is configured compared to the original one so it might have to do some modifications
or we might get lucky we're going to have to do some modifying so now that that bracket fits I do need to
do a modification to the blade in order to fit a standoff here so the standoff is going
to be used to support this end of the bracket all it is is a piece of 1045 material that's
been drilled and tapped to suit a certain thread we keep them in stock for all different
threads metric and Imperial commonly used for attaching something onto a machine such
as a guard or a ladder or even a hydraulic pipe they're just a quick and easy way of
fastening something to a machine so what I'm going to have to do I'm going to have to remove
a little bit of material with the oxy weld the standoff in and then we can refit the
bracket for the GPS Pole so we're not going to be fitting the GPS bracket
back to the left hand side of the blade because this machine only runs a single GPS pole there
is no purpose for it to be there and the customer has asked can we not fit it and just send
it back to them right oh guys so there's our blade replacement
completed there's really only a couple of hours work in something like this even though
we did have to modify the bracket and also weld on a new standoff everything went pretty
straightforward it was a lot easier to do a replacement of the blade rather than trying
to repair the damaged one if you add up the cost of what it would have taken to repair
that damaged blade plus the new wear skin plus the guide and all the hours that would
have gone into that it would have actually been more expensive to go down that path than
it was the path we chose so the customer has decided not to put a wear skin on the new blade
and that is because it is a high hour machine and it only plans to keep it for another six
months or so because we didn't have to wait for the new skin to be cut and then pressed
we were able to turn this job around very quickly so the customer is going to be able
to send it back to work and start earning money straight away so that's this one done
thanks for watching I'm just gonna try and get a thumbnail photo
what are you doing oh is that the thumbnail shot right there how'd you start that right so this is the new blade
it is a good quality blade [sigh] righto guys so that is our blade oh [ __ ] me it also need oh [ __ ] up [ __ ] me [ __ ] me I've lost it again so that was good [Karen] but
but what [Karen] is that it
that's it OH [Karen] argh my camera's overheating give me back my [ __ ] socket [phone ringing] [Karen] oh wow yeah that was lovely [coughing] Solid
Rock Solid they fit good NOT that is not right ahhh double [ __ ] [weird alien noise]
woaaah what was that Alien's [weird noise] what the hell [Karen] wow it's black stop don't continue
[Laughter] did you not read the lid
I thought I picked up the right obviously not how old is that
probably old I don't even know where I got it phwoar it smells weird right we're ready
[Karen] whoa hang on it ain't even dry [excited Homey noises] ah you took it off again stay
sit sit sit do you want that jacket off now
[squeak] come on is that it your work's done good boy
