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Cat D6C Blade attachment

Mcrafty1

Mcrafty1

Senior Member
My question is the ball that the blade arms attach to on the side of the track frame, Mine are held on with 6 bolts, they are considerably worn and I would like to price out new ones and need to know what to ask the dealer for in hopes of avoiding the confusion I went through getting the correct corner bits. I have manuals for the tractor, but as you probably all know...The tractor manuals don't cover the blade. If anyone knows what Cat calls those I'd appreciate the help. Oh yeah, serial# for the machine is 76A5579 but there aren't any #, stamped or on a plate or evidence there ever was one...that info is long gone. I suppose if I have to I can build up the ones on the machine but I'm going to guess that would require at least a full inch of weld at the deepest point.
 
Mcrafty1

Mcrafty1

Senior Member
skyking1 said:
my WAG is that the price will have you welding that up in no time.
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Most likely, there's a lot of weight there..I figured as much.
Thanks for the reply.

Another question...I don't do a lot of welding would you know what a good rod to use in that application? I have the usual 7018's and 6011's. Mostly 6011's would they be ok?
 
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Puffie40

Well-Known Member
Mcrafty1 said:
My question is the ball that the blade arms attach to on the side of the track frame, Mine are held on with 6 bolts, they are considerably worn and I would like to price out new ones and need to know what to ask the dealer for in hopes of avoiding the confusion I went through getting the correct corner bits. I have manuals for the tractor, but as you probably all know...The tractor manuals don't cover the blade. If anyone knows what Cat calls those I'd appreciate the help.
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I have known those as "Trunnions". You would likely build them up with the same material as what you would use to build up undercarriage parts.
 
John C.

John C.

Senior Member
I have tried welding them a couple of times. It doesn't work. The weld will be ground off in a couple of weeks.

Tell the parts guy you need a trunnion ball. You used to be able to just buy the ball with the mount end that plugs into the bolt on bracket. You would then air arc out the old one and weld in the new one. You can also purchase the assembly complete and just unbolt the old and install the new.

If your trunnion ball is shot, then so is the socket on the blade push beam. You can purchase that socket complete and again do the air arc removal. In the past I have cut off the socket and welded the end cap on. You only have to buy an end cap then.
 
Mcrafty1

Mcrafty1

Senior Member
Thanks for the replies. I'm not looking for perfection really I just want to take a lot of the slop out so the blade doesn't sway so far side to side. I don't use the tractor a lot so I like the idea of building the ball up with weld, If want it to last a while longer than two weeks though. There must be something for material that would last longer than that, I'll check if anyone knows if there is. If not I'll decide what other way to go.
 
Mcrafty1

Mcrafty1

Senior Member
Tones said:
IIRC there were shims on the trunion caps when they were new
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I would imagine there was, long since gone now the front of the ball is worn of an inch or so, the blade swings side to side now when it's in the air. I'm just trying to take some of that slop out, I don't use the tractor much so I'm not looking for 'as new tight' if I had a lot of work for the machine I'd fix it with new parts but that's just not the case for me.
 
W

Welder Dave

Senior Member
If you wanted to build them up with weld use Stoody Build Up electrodes or equivalent and preheat before welding. It welds similar to 7018 but is medium hardness between 7018 and full hardfacing. It is used on idlers and also used to build parts up prior to hardfacing. The important aspect is it doesn't mushroom like 7018. It can be deposited in multiple layers unlike hardfacing and won't spall off. It is also easier to grind than hardfacing.
 
John C.

John C.

Senior Member
Bob got there before me. That movement is all in the K links at the front of the machine. Most machines have those shoved up tight and welded in place when the balls and sockets are shot.
 
OzDozer

OzDozer

Senior Member
The original trunnion faces are harder than the hobs of He**, and the hardening is deep. On my D6C's I had moderate success building up the lower depth of the worn area with 7018, then finishing off with 2 or 3 passes of a high-chrome-content, hardfacing electrode. But nothing you do with weld, will come anywhere near the wear resistance of a new trunnion ball.
However, to buy new trunnion balls you'll need a large overdraft, and you'll need to sacrifice your firstborn.

To fix the wear in the mating part on the rearmost end of the push arm/side arm, I bought genuine Cat trunnion caps, then torched off the worn section of the casting welded on the push arm, and then welded trunnion caps on there, using 7018. You need to Vee out the area to be welded, to ensure a decent depth of weld where the cap is attached.
 
Mcrafty1

Mcrafty1

Senior Member
Lots of good advice here, Thanks. Like I said though, this machine sees so little use I just wouldn't spend the kind of money it would take to make it 'as new' nor do I ever expect what I do to be a long lasting repair, I'm going to start with building up the trunnion balls and work my way from there, If I had to guess I'd say the Balls and side arm ends are all original on the machine, The tractor is now 55 years old and I'm turning 67 in two days. If I can get the blade tightened up a bit for reasonable money, that's going to be as far as I go with it. No matter what I do it isn't going to make the machine worth any more when I decide to sell it, or if I die before that, my wife isn't going to get anymore for it.

I appreciate all you have advised and realize that when you reply to me you are actually telling anyone that reads this forum what they should do if they want a lasting, quality repair. All answers if adhered to would be the right way to fix this problem. Know that I realize that, but try and see it from my prospective. Thanks again.
 
OzDozer

OzDozer

Senior Member
You got the right approach. I did full-time contracting with my D6C's in the 60's and '70's - and even back then, purchasing new trunnion balls simply wasn't even worthy of consideration. There are quite likely a whole lot more reasonably-priced aftermarket trunnion balls available today - but the buildup with weld is still the most economical repair.
You really should run some weld on the pins and pinholes in the rest of the blade too, to take some of the sloppiness out, as the wear creates a hammering effect, and this will lead to components cracking.
 
Mcrafty1

Mcrafty1

Senior Member
Ok thanks, I'll start with the runnion balls and move out from there. I'll try and get a couple of pictures so everyone can see what I'm facing, it's winter here now and the machine sits outside so I don't know how good they'll be but the trunnion ball wear should be easy to get a picture of. Thanks again everyone for all the good advice, I'm on a budget here so I need to make some consessions on the extent I go to get where I want to be.
 
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