Well you learn something new every day. On the BX1850's and the early 1860's, the drive shaft assembly is different than the later 1860's and beyond I suspect. In the later version, Kubota introduced a new part--they call it a spacer. It is installed between the motor pulley and the front coupling. It is 2" long and what this does is place the front coupling rearward and just beyond the under belly superstructre frame opening. Because of this addition, they also shortened the shaft by a like amount 2". The reason I know this is that I purchased a used complete shaft assembly listed on Ebay as for a BX1850/60. I wanted to take it apart and explore cutting the shaft in half and fashioning a new sleeve to connect the two ends. I do believe that a rigid shaft coupling could be employed if one wanted to do it.
However, looking at the newer assembly, I am beginning to believe that Kubota made a change because of all the problems one needs to go though to simply replace a fan. I believe that--in looking things over--the spacer can be removed or at least pushed aside allowing the front shaft coupling to be moved forward thus allowing the rear coupling to be freed from the transmission spline without having to move the motor forward as in the older models discussed here. I brought this new assembly to the attention of a local Kubota dealer service tech. and after reviewing the newer version he agrees with my assumption (I know what assumptions can lead to).
However, after removing the floor pan to take a closer look, I am bewildered. Everyone I have talked to and from the discussions here, the shaft must be removed from through the top. Okay, I will buy that; however, in eye-balling the shaft in place, I am wondering just how in the H the front coupling can be drawn out of the available clearing without having to remove some of the hydro piping and the center brace under the battery box. The hub of the front coupling must be 3" OD and there certainly isn't that much of an opening with just the floor pan removed.
Now there must be someone out there, maybe even a Kubota tech. who has actually accomplished this project using the new shaft assembly. First, am I thinking correctly that the added spacer was introduced for exactly the reason I think it was done for--ease of removal? Second, can a newer assembly with the spacer be removed and installed without having to move the motor like before? Third, can the front coupling--attached to the shaft as a complete assembly--be withdrawn from the tractor by the removal of the floor pan alone, or is it necessary to remove more items from immediately below the battery shelf in order to increase the clearance?
I am now thinking that if you have an older style shaft assembly, rather than move the motor, cut the shaft and pull the two end. Then order a new shorter shaft, spacer and front coupling since Kubota seems to believe the coupling is different. Install the rear coupling on the new shaft, including the new fan. Then insert the front pointing shaft with the coupling ball receiver mounted on the shaft through the floor opening. From the bottom, install the front coupling parts and snap ring. Shaft now ready to install.
Comments? and has anyone worked with a newer style shaft assembly?
