Pinion nut torque spec

I am going to replace the yoke on my 30 tomorrow and I am just wondering if anyone knows what to torque the nut down to, HP dana 30.

-Alex

Nobody?

-Alex

I mark the nut and shaft with a punch, back it off (I use a rust dissolving acidic penetrating oil), clean up the the threads, oil and torque the nut until the marks line up (remember the torque reading). Reinstall the new yoke with the same torque, usually around 150 ft lbs. I think the book says above 160 ft lbs-260 ft lbs. I have a three foot long 3/4" drive torque wrench, a hundred and sixty pounds of torque needs a big torque wrench or a lot of butt.
If you have the carrier out you can double check your pinion bearing pre load (usually loose with older bearings), usually measured in inch pounds. Check the bearing for smoothness and low noise, feel for hitches and other signs the bearing may be worn out of round or extremely loose.
Without removing the carrier, I turn the wheels to the front, remove the calipers and disc, turn the yoke with my hand. Put a torque wrench on the yoke nut and see how much effort is required to turn the yoke. I can often turn it with two fingers and a thumb, I usually do it mostly by feel.
I try to reinstall the yoke without things tightening up too much. They shouldn't, but I've seen guys reinstall a yoke and not be able to turn the new yoke with a wrench, which can burn up your bearings quick (chit happens).
I'm sure there are specifications for the bearing pre load out there someplace, though it's doubtful they will be accurate with the carrier and axles still in place. I do it mostly by feel.
The book recommends using a new pinion nut, I inspect the treads, if they are rusted out a new nut would be a good idea.

I put it on till it's tight and then go by the preload spec in the Randys differential manual.

You will need an inch pound torque wrench though. And it's tough to do because there is so little backlash. You will be able to spin it one way till you hear the gears "click" or mesh then put the torque wrench on and make sure the preload is right.

Then tap it with a mallet a few times and keep tightening till it's right.

HTH. Call me if you are confused.

Install torque on the nut is actually less important than bearing preload - I think I have the spec for "used" bearings up on my site (check - in the Tech Archives. If I don't have your year listed, find one that's close, I haven't built the "unit" pages yet for the axles, engines, and such.)

You will need a dial-type wrench that reads in pound-inches, as you will have to take a preload reading before you take things to bits, and you'll need to check it when you're putting it back together. Also note that pinion preload figures are usually exactly that - pinion shaft & bearings only, no carrier or shafts. I've got some axle specs that give with pinon/differential preload, but it's still no shafts (bearing preload is the amount of torque that is required to start them turning.)

It is very difficult to take an accurate preload reading with the carrier in place, because I seem to recall the backlash spec being down around .005"-.009" - and that's not a lot of room.

Theres TOOO much thought going in to this!

Remove pinion nut, remove yoke, Replace seal (best time to do it other then complete gear removal), then slide new yoke on and with most any impact that has less then about 300lb lbs of tightening torque rating, just impact the nut on and watch for it the socket to stop spinning freely. ONCE the nut stops turning and you will hear the psshh turn to Bang bang on the gun, your done. That simple.

If you do it by hand your doing much better though. Just tighten with a decent 1/2" ratchet till you not longer can without he/man grunting.

Must use a new pinion nut. They are crush nuts and wont back off for nothing (typically).

Once the nut pulls the inner and outer pinion bearings together on to the crush sleeve, it will go from about 50-60lbs of torque needed to turn the nut to about 350-400lbs, that is when the crush sleeve starts to "crush" and that is ALL your trying to avoid.

You can NOT adjust pinion preload with out removing everything from inside the axle (axles, carrier, pinion seal). SO unless yoru going to do all that work. then above will work great for ya.

ive replaced probably 6-7 rear yokes (needs to be more precise then a front yoke), and my method has never failed me after thousands of miles and many different jeeps

count number of threads which stick out, or use some method of knowing how far on the nut is. i liked the punch method stated about. remove yoke for whatever reason, and reinstall yoke to that position, and give it a "little snug up"