Hello red square, I restored an 857 last year and I have been having a blast with it but I have noticed a bit of a problem this past summer and and winter with the transmission. There seems to be a bit of a hesitation in the machine when it is running in 3rd gear while going up hill. The best way i can describe the problem is that it is like the tractor has oval wheels, it seems to pull then let off, pull then let off, pull then let off. I cannot for the life of me figure out the problem with it. It seems to really only happen in 3rd gear.... The other issue is that occasionally i am getting a bit of a knock on something that sounds hollow, like if i were to knock on a metal door or a hollow oil drum. Has anyone had this issure before? Is this something that is fixable? When I did this restoration I did not take the transmission apart at all, the only thing I did was take it off of the machine, strip it and paint it. I think that would eliminate any mechanic's error but that doesn't mean I didnt knock something out of place in any of the times I moved out around in the garage. The only other thing I did to it is put in new gear oil, it ran. I am frustrated and puzzled, it never had an issue like this before it was restored.... Please comment whatever you think may be the issue and thanks for the help --Eric Gell