743 Power Transfer Yolk

[kadecole]

I was investigating my 743 and noticed some problems with my Power Transfer Yolk. You can see the damage to the center teeth in this picture:

So I ordered a replacement. The replacement came with this removable cap for the center piece. I can not use that cap as it is just loose and does not stay put.

I was wondering what the implications are of using this Yolk with the center being open? I have posted some more pictures in an album called 743 Power Transfer Yolk. Thanks for your time.

 

[craigb93]

That type plug is intended to expand when you hammer the center. It is to retain the grease along the spline to prevent the wear you got on the old one. There should be a tapped hole for a zerk fitting along the barrel of the yoke.

 

[kadecole]

That type plug is intended to expand when you hammer the center. It is to retain the grease along the spline to prevent the wear you got on the old one. There should be a tapped hole for a zerk fitting along the barrel of the yoke.

Thanks. The "hammer into place" thought crossed my mind and I even tried a little, but it was so loose I thought I was wrong. I figured it might be a plug since it made no sense to have it open with the grease zerk. Should I add anything to help retain the plug, like jb or weld it on? Or will hammering into place be enough? Also when attaching to the U-joint should I use some blue thread lock?

 

[rjitreeman0909]

Thanks. The "hammer into place" thought crossed my mind and I even tried a little, but it was so loose I thought I was wrong. I figured it might be a plug since it made no sense to have it open with the grease zerk. Should I add anything to help retain the plug, like jb or weld it on? Or will hammering into place be enough? Also when attaching to the U-joint should I use some blue thread lock?

The plug is called a welch plug. Insert with dome outward. It will take substantial force to get it to go flat. I recommend setting the flat face of a ball pean hammer on the plug and hit it with another hammer (considered a no no but some times necessary). or even better put the assembly and hammer in a hydraulic press. Dry without sealant is fine. Looking at your old coupling, I would have concern for alignment or condion of other parts in that drive line. Wear patter suggests a long term wobble. What is condition of matng spline?

 

[kadecole]

The plug is called a welch plug. Insert with dome outward. It will take substantial force to get it to go flat. I recommend setting the flat face of a ball pean hammer on the plug and hit it with another hammer (considered a no no but some times necessary). or even better put the assembly and hammer in a hydraulic press. Dry without sealant is fine. Looking at your old coupling, I would have concern for alignment or condion of other parts in that drive line. Wear patter suggests a long term wobble. What is condition of matng spline?

The previous owner had the hydraulic pump repaired and the spline looks good! Just a little surface rust on the spline but it mates well with the new yolk. The rubber motor mounts were destroyed so I ordered new ones. I think they gave up and caused the pump to leak due to too much wobble in the U-joint and connecting spline or misalignment between the pump and motor. The U-joint feels tight but shows sign of wear from wobble, so I am leaning towards replacing the whole U-joint.