So i had a shop rebuild my 489 and made it a posi. So now i go to put the bolts in the yoke and one is really loose/bad . Guess i should have checked before i sent out. So i figure i'll drill it deeper and use a longer grade 8 bolt. WELL the tap broke off and aint getting it out. Trust me i know , my father was a machinist and i was going easy ...Bottom line now is i need to change the yoke. The rear end is all together really to go in... So can i change the yoke out ? 489 is a crush sleeve correct? Is there a way i can get it off and put a another yoke on?

Check with shop first & find out which method they used for the setup.
Crush sleeve or otherwise.

Crush sleeve from the factory, but there are crush sleeve eliminators available for the 489 case. Dr Diff sells them. Either way, start by measuring the rotaional torque of the pinion with an inch pound torque wrench (needle type). This is pinion bearing preload. With new bearings it should measure 14-19 inch lbs to rotate the pinion. Used beasring should measure 6-9 inch lbs. when set-up correctly. Slightly higher numbers are OK when the ring gear is installed. Write down the number, remove and replace the yoke. Torque to 170 ft.lbs. Measure rotaional torque with needle type inch pound torque wrench. If less than where you started, tighten nut slightly (I do in 15 degree increments). Measure rotaional torque again. Repeat until rotaional torque is slightly higher than when you started, one to five inch pounds higher. This is for crush sleeve only.
For solid spacer, torque to specifications, using new nut or locktite, and measure rotaional torque to confirm it's within specs and similiar to where it was before removal. No need to exceed 170 ft. lbs.

Do not use an impact gun to tighten yoke nut. You'll hammer the bearings. You can use a hot plate to heat the yoke prior to slipping it over the splines, draw down with nut and washer. Do not hammer it on unless you remove the differential from the housing and you can support the pinion.

Thanks ! going to give it a try . Will call shop and see what he did. Thanks for the info.

This , get another yoke , check to make sure the bolt holes are good , and have the shop swap the yoke. It can be done with a crush sleeve but you have to know what you are doing ...

If it has a crush sleeve no big problem. Before you remove the big nut, simply feel the amount of drag or measure it with an inch pound torque wrench, If they did it right you will feel a slight drag about 20 to 30 inch lbs. It takes a lot more force to collapse the sleeve than the minimum pinion nut torque which is 240lbs. Just replace and tighten to spec, if the preload rotational torque does not change no issue.

I've known a few that put a few shims in to loosen the preload that allows one to crush the sleeve a bit more to reset the preload

Take it off l, install the new one with lock tight on the nut. The process is just preloading the bearings, you don’t even need a crush sleeve if the nut stays tight, it ain’t rocket science.

Another approach would be to ditch the sleeve, buy a spacer kit, and reinstall with shims.

That should have been done originally , to do it now requires pulling the differential out because the crush sleeve is bigger than the outer bearing size .

The problem is that if the pinion nut isn’t tightened SLIGHTLY (and I mean slightly) more then the pinion has an even better opportunity to slam the crush sleeve during operation, which it does anyway.

done fixed , and on to the next project with the Gen3 72 Cuda.

The only purpose of the sleeve is to torque the nut to 250 ft lbs (so it won’t come lose) not hold bearings apart. Besides under power the pinion is forced forward.

Didn't think about that

So what was your solution?