[TenTec] Ten-Tec PTOs

[Phil Chambley Sr.]

I haven't seen this mentioned in any discussion of re-builds, so I guess I will.

Apart from the well-known "marble rolling through chewing gum" effect that the aging grease has on operation, there's one other thing I've noticed over years of repairs.  The little plastic thrust-bearing cup on the back side of the PTO box has a tendency to stress-relieve over time.  When this happens, the pressure on the shaft, along with the pressure the orbital balls should have against the race in the planetary drive, is reduced.  Loss of this pressure is what causes the drive to slip.  I have noticed, almost without exception, deformation on the "ears" of the thrust cups in afflicted PTOs.

There are usually a couple of washers between the thrust cup and the PTO housing.  I move these from there, and put them under the heads of the #4 screws, so the pressure between the planetary bearings and the brass race increases, because the compression system is about .012" shorter.

This is, of course, after all the old grease is removed and a suitable replacement lubricant is applied.

I've never seen deep grooves worn into the races.  Given the fact that the assembly is lubricated, I imagine it would take an enormous amount of use to do that, especially since the relatively soft plastic thrust cup is exerting all the pressure.

Your mileage may vary.

73
Phil C. Sr.
k4dpk