Line boring and Bore welding CAT 789 Dump Truck suspension part | Sir Meccanica WS2

Where is he? How you going guys? Curtis from Cutting Edge Engineering. Today's job is a 789 rear strut rod. It's coming for an iReclaim. So it's off a 789 dump truck. It's the rear suspension strut for the truck. Being a suspension strut or a shock absorber, they do take quite a lot of punishment. When stuff goes wrong and it isn't caught in time, it goes severely wrong and does a lot of damage. As you can see, down in here the bearings come apart. After the bearings started to come apart and the truck was being used, all the components just hammered each other together. It's actually destroyed the eye and impregnated a lot of bearing material and other bits and pieces into the eye. So we're going to have to do a bit of work to grind all this stuff out as it can't be line bored with all that bearing material in there. If I was to attempt to line bore this using carbide inserts, I would burn up inserts like they were going out of fashion. Being how hard the material is, they just destroy inserts. So the first thing we've got to do, we'll get everything set up ready to go. I'll get in there with a big barrel grinder and I'll grind out the majority of the bearing material I can just to avoid destroying inserts. After we do that, we'll take a couple of cuts and hopefully we get everything out then we can start to repair it. In case we didn't know where the damage was, there's some handy arrows. Yep, they help. You might recognise what this fixture is I'm bolting this strut down to. It's actually one of the pallets out of our Toshiba milling machine. Very handy that it's got 16mm threads in it where you can use our clamp down kits to hold big items like this. To try and set this up on a bench in some V blocks or whatever would be very difficult. Being it's sheer size and height, I wouldn't trust it standing alone on the floor. So put a nice big bit of something heavy underneath it the other pallet off the milling machine clamp it down, you've got a nice stable work platform. So what I would like to say is everyone always asks isn't it cheaper to buy new than repair an old one? No. No way. This strut to buy new from the manufacturer would be tens of thousands of dollars. This repair will take less than a day it's not cheaper to buy a new one. That's all bearing material. Parts of bearings. Trim as much of it out as we can. Music Righto guys so we've got our WS2 line boring machine set up on the job now. First thing we had to do was actually set the bar in the centre of the hole. Being that the hole is quite damaged in there you've got a few different methods you can use. We use a shop made centering plug so the outside diameter of that plug is actually the right size that the bearing is going to be when it's finished. I did have to tap these into the hole to settle up so it is pretty tight in there. The real area that's only damaged is in the base of the eye. Being that this is such a large diameter hole it's a little bit over 200mm which is nearly about 8 bananas. We've had to use our Surmechanica tool holder extension which just clamps over the bar. The tool can then be adjusted in and out. So being that there is a lot of bearing material inside here I'm not going to go and use my ECGT inserts they are expensive and I'm running out of them. So we do have these inserts these are a CCGT a little bit more sizeable can take a little bit more punishment so a pretty good insert to go into a hole like this and try and open it up and clean it out. So a lot of you might be wondering why this isn't being done in say a horizontal borer or a big milling machine I've been looking for a good condition horizontal borer for a long time now. I haven't found one that I would consider to be in decent condition enough for me to spend any money on it so it would be a perfect job for that. I don't have one so we're just going to persevere with the line borer. Righto guys so we're putting all this back together again we're going to take another cut out of the eye turns out there was a previous repair in there. So he cut corners he welded over porosity which we found in the snap ring groove it is quite common to find people doing the wrong thing when it can't be seen after it's covered up for what we're going to do what we're doing now we do tend to find a lot of dodgy repairs the problem with welding over porosity it's not welding over the porosity, it's because there's so much grease trapped in the porosity holes you can't weld over grease so when you do start a weld there it just tends to pop and carry on and it just spits ---- everywhere and you can't weld it so it's got to be blown out, make it all new material again, so clean it up put a new layer of weld in there and be done with it so we're going to push this out a little bit further take a little bit more material out and then hopefully we'll be able to lay a decent weld in there righto guys so we've put our second layer of weld in, what we're going to do now we're going to put the boring bar back in we're just going to skim the top of that second layer off for a nice clean surface for our third and final layer not a good idea to stack multiple layers of weld on each other so after every two I'll put the boring bar in and I'll skim the top off of the second one so my third layer's got a nice clean surface to go to oh well, not much to build up