Combines Changing MF 750 concave

Deerebines

Guest
1: douse with gas 2: throw match 3: call insurance agent and collect money and go buy a different color machine. All kidding aside you are in for one heck of a job. The square shaft inside of the stone trap door is a mother to beat out. You will end up having to take a tire off so you can beat the living heck out of it and so the shaft can come clear out. When you put that baby back anti-seize it real well. It's been several years since I helped pop with his but I can still remember how much of a chore and miserable it was. I just can't remember step by step how we did it. You new concave supplier should be able to tell you how to do it. I'd rack thier brains for all imfo you could get and good luck.....That is an honory job. Take care Deerebines
 

JJS

Guest
The hex shaft in the stone trap is about the hardest thing to remove. But one thing that might help in that reguard, is that only abour 2" on each end of the door is hexed inside. The rest of the tube is hollow. You can drill small a hole about that far in, and shoot some penetraiting oil in there. This will help greatly. Good luck! Joe
 

Deerebines

Guest
Joe I remember us using the torch to cut a small hole in that stone trap. Was that so we could pick up the shaft when it came through the hollow spot and guide it through the holeIJ I'm trying to remember but I think we put those concaves in about 15 years ago or better. I have forgotten so much except the shaft, the torched hole, and when the monster fell off of our jack stand because it wasn't strong enough.....I think I filled my pants after that little episode.
 

JJS

Guest
I never cut a hole in mine. Just heat and hammmmmer. But after we got it apart, and looked at it we seen how it was made. Then made a note for the next time. That was only 2 years later. Ran a stone through, and bent the concave. But it came apart easy that time. no heat needed.The stone didn't hurt the cyl. at all, but put about a 1.5 inch bow in the concave. But I do remember that getting that shaft out the firs time, was the hardest part of the job. Joe
 

JJS

Guest
Also make note of the position of the shaft (holes on end) to the door. Joe
 

rotor

Guest
For the people who like to work like a mule here is a hint to pound out the hex shaft. We purchased a electric jack hammer at a construction auction and have been useing it since for removing shafts and other circumstances were a large hammer or heating is required. To slide the concave in to place we use a engine hoist and blocks on the grain pan . PS we change our concaves twice a year for beans (1 1_2 in. wire spacing) and narrow for grain and canola and then back to wide concaves for large peas.