I just installed new Superior axles and replaced the bearings and seals. I also replaced a leaky yoke seal. Problem is my CP impact wrench cannot produce any preload on the pinion bearing. The pinion is in there tight (no looseness, fore/aft movement) but I cannot generate any preload. Can I run it this way? If not, what are the methods of holding the pinion gear while tightening the nut? I tried using the parking brake but that wasn’t working.
Thanks.

I use a BFBB. :) I made a long handle out of a piece of 1/4" mild steel and I bolt that to the yoke. Then I slip a 3' long piece of pipe over my breaker bar. If the rearend is still in the car, you should be able to use the frame or something as a stop for the handle and use both hands on the breaker bar. It takes a lot of torque to crush the sleeve. Go slowly and crank on it in slow increments.

You might be able to find an impact with enough power to crush the sleeve but I prefer the feel of doing it manually with a breaker bar.

It takes around 300 foot pounds to crush the spacer. It's no fun, but it MUST be done. You must set the bearing preload correctly or you will trash the bearings and gears.

Did you pull the pinion and replace that bearing as well? Or did you just replace the axle bearings and seals? If you didn't touch the pinion bearing or it's crush sleeve, (only replaced the pinion seal), then just tighten it back up to about 125ft-lbs with some sealer on the splines and locktite on the threads and you will be good to go.....correct Freddie?

Yes, you can go as much as 175 foot pounds and be safe with the original crush spacer. I think we need a little more information on this. Did you replace the pinion bearings and spacer, and do you have the differential removed?

Let me add some more info. I had replaced the gears and differential years ago. After recently changing to a TKO600 I upgraded the rear yoke. At the time I did not replace the yoke seal as I felt it didn't have that many miles. Well, it began leaking almost immediately. So, when I replaced the axles last weekend I also changed out the seal. The pinion spacer had been crushed on the rebuild. Does this info change anyone's answer?

So basically as far as the pinion bearing/crush sleeve is concerned, the nut came off, old seal removed, new seal installed and the nut put back on. No problem, just tighten the nut back to 125 ft pounds or so and you are good. I did the same thing recently. Installed a TKO-600 and upgraded the rear yoke to a 1350 series. While I was back there, I installed a new seal. Cranked the nut back on to about 140 ft-lbs and away I went.

That is correct. You can go as far as 175 foot pounds if this is a 12 bolt. Did you put sealant around the outside of the seal and inside the yoke in the splines? Did you grease the lip of the seal? Use red Lock Tight on the threads.

Yes it's a 12 bolt.
Yes, sealer on the outside of seal and splines.
Yes, I put some gear oil on the lip of the seal.
Yes, I used red locktite on the nut.

Now, how do I reach 175 ft/lb? I have a breaker bar and a length of pipe but I cannot get the car high enough to use all that leverage.

Now, how do I reach 175 ft/lb? I have a breaker bar and a length of pipe but I cannot get the car high enough to use all that leverage.

Eat your Wheaties Nancy! :D just kidding ;)
That was the tough part. What I did was jack up the rear of the car with the wheels on it and place ramps under the wheels. Then I locked the e-brake as hard as I could go. I used a big a$$ pipe wrench on the yoke. With a piece of pipe on the end of the pipe wrench, I wedged it to the ground. Then used my machinsist buddy's 3/4" drive torque wrench to pull it tight. Hope this helps. You are gonna like that 5th gear. :)

If you do this with the rear tires touching, just be very carefull that you don't let the car run over you. 175 foot pounds of torque on the pinion can easily over power the parking brake and get you killed. If you have a large pipe wrench you can use it to hold the yoke while you turn the pinion nut. As always, be carefull when working under a car.

Excellent advice. Thanks!