ours has the same blade. without the modifications. no, silly me bush "fixes".

you can see the remains of the rack teeth i mentioned. we had too change the bolts on ours as they were seized solid. fitted the new ones with a smear of anti-seize wont be a problem again.
another spot for play is the pivots on the end of the blade, very easy to correct simply make a sleeve out of steel or plastic water pipe.

like I said anti- seize is your friend a dab on all threads unless they specifically must be dry, will save headaches later if it ever needs to be removed. A retired mechanic told me that, he did his apprenticeship on a sugar plantation that was on salt marsh country they put graphite grease or anti-seize on all fasteners and mating faces.

and that cutter edge is worn out from what i can see in the photos it should be like Rax's machine (it looks like he's turned his)and hang a good distance below the blade especially if you going to work the machine it saves the blade they are only mild steel and cast steel they will wear. try and get some cutter edge off a grader often they dont get turned and just get thrown away, even if you had to make new holes it would work. and it might be free or scrap price.

Hi, tassletrader.
Old Magnet is right about those triangles. There should be a pivot for the lower rear corner of those triangles over the track frame but under the top of the track and ahead of the carrier roller - see rax200's photo. SOMEBODY has done some SERIOUS BUTCHERY to your set-up. That pivot would have another mounting plate on the inside of the track frame to carry a cross tube and the inner end of that pivot shaft.

Just my 0.02.

yeah where is the mount for the blade lift pivot. with that he would be limited on vertical travel of the blade you wouldn't be able to do a full depth cut not enough travel.

maybe this is a converted ag machine like ours was. the difference being the addition of the hydraulics and dozer side frames which simply bolt on. this must either be home-made or bits where missing/cannibalised for another machine before conversion.

a another member had posted photos of a toolbar that mounted on those triangle pivots. to use it you unbolted the blade arms and pulled the pins on the blade lift links and the tool bar clamped into the triangles and hang out the back.

also that blade isnt hanging square there should be the same height on both sides that is how the tilt is set. it will make the blade cut a taper.

the other place you get play is the blade arm trunnions (pivot) new and reconditioned are available from the dealer and after-market is too. but as a quick fix to take up the slop i would just get some thick leather soak it in neatsfoot oil, pack it out and bolt up tight as it wears add more leather.

if you look closely it appears somewun that chinese bloke has torched the proper triangle pivot mount off the side frame. so maybe it broke or they had cannibalised it to fix another.
i know our machine was repaired in that area the cousin told us it was when we bought it from them his son in law made new bushings for it and welded it back in place and ive seen others with repairs to that pivot.