OK, I'll follow-up on the yoke swap then. Now that you've read the FSM on how they say to do it (adjust bearing preload by in/lb drag) you can use a modified method to get it done quickly with the tools you have. Here's what you can do:
Remove the axles (if in the car) to reduce the drag to turn the yoke by hand. Remove the pinion nut with the impact gun. Use a gear/bearing/something puller to take the pinion yoke off. Sometimes they're easy and just a few taps with a dead-blow mallet, babbit mallet or other soft force will get it off without tweaking it.
Next the seal comes out. One trick with seals is you can collapse them on an edge and they will fall out. Using a small cape chisel (so the bore the seal sits in is not damaged or scratched) and drive it down the edge of the seal to push the seal inward. When you do, the diameter of the seal gets smaller and it slips or falls out of the hole. If the seal is at the outside of an assembly (like this one), a regular chisel, punch or drift can be used to do the same thing by just angling the punch towards the inside and give it a couple hits to collapse the seal inwards.
So now you're ready for re-assembly. Use an open-center seal driver, or piece of PVC pipe, big socket, or whatever fits the seal diameter to evenly drive the new seal in. I think I used a lower timing gear once as a seal driver.
A light smear of non-hardening sealer around the edge is good insurance. Drive it in level and square. Slide the yoke on and use a new pinion nut if available, as they will grip better and come with a thread sealer on them. The sealer stops lube from slowly creeping through the threads to the outside and making a mess over time. If using the old nut, put a dab of sealer on the threads and run it on with the impact gun, but only until it makes contact.
Here's the trick to avoid damage to the bearings and get proper bearing preload.
This trick ONLY works when using the same parts and crush sleeve that was in it before. If any hard parts are changed (pinion gear, bearings or races) then you have to use the full Ford method with a new crush sleeve or spacer sleeve and shims to set the new preload. Also, this method requires extreme care as you cannot go too far without having to pull the assembly follow the rebuild process. You can NOT back-off if you go too far, as the sleeve will be over-crushed and the bearing races will likely be damaged. A new sleeve and bearing assemblies must then be installed.
Now you see why Ford avoids any mention of power tools for this. A careless grease-monkey under time pressure on the clock can slap it together and ruin parts easily. If you screw-up, the worst case is having to pull the pinion assembly and install new bearings, races and sleeve using the full FSM procedure without the impact. However, it can easily be done - just go slow and be careful.
If you have a torque beam or running torque meter, measure the running torque now (force to maintain smooth, even rotation of the assembly). Stop and feel the force required to continuously rotate the yoke by hand - the "running torque". Spin it several times to get a good feel for it. The FSM states a tiny drag to establish preload, and it's so small that it's hard to feel with all the other drag that's already in there. So, get a good feel for how hard it is to spin, and start driving the nut on, stopping to feel for ANY sign of increased drag as you go. You can tell as you get close as the wobble and slack of parts goes away and the sound changes. Hit it, feel it, hit it, and so on until you feel ANY increase in drag. STOP.
The slight increase in drag that a person can feel is right at the spec's in the FSM. If you have a running IN/LB toque beam or dial wrench, you can test against pre-torque numbers to verify. So, that's it. Note how easy it is, yet how simple it could be to blow the whole process and either over-torque causing bearing damage, or excess preload, causing the bearings to be wiped-out in a few miles. Or, backing-off causing the over-crushed sleeve to leave spacing that will ruin the bearings quickly. You can do this well in a few minutes with no problems if you use care. Go for it.
galax-z, I had no intention of muscling-in while you were giving advice, but I didn't want to leave him hanging or ruining parts. Please don't take offense.
David
