The Stovebolt Site Forums The Shop Area Engine Shop Loose Pinion Nut

When installing the driveshaft after swapping in a T-5 I noticed the pinion nut on the rear axle was loose, not even finger tight. Something else left from the DPO! Do I have to remove the pumpkin and then go thru the pre-load & torque settings? How far off would it be if I checked the pre-load with it still in the housing? How long will it last if I just torque to about the middle of the specs without re-checking the pre-load on the bearing?

As you know, the safe answer, and the right answer is to tear it apart and double check everything according to the service manual.

Depending on what the rear is worth to you, how long you need it to last, and what you expect it to do, you could just tighten it and give it a try.... but there may be more to the problem than that, best thing to do is plan on a rebuild now, the you know what you have when you are really counting on it not to fail.

Grigg

Id imagine it may have been the PO installing a new pinion seal??? and not remembering to retighten it. I bet it wouldnt be to hard to get the info and pull the back cover and check the backlash and ring/pinion contact and then youd know for sure whether or not youd need to tear into and rebuild the rear.

Let us know what you find and plan on doing!

Jeff

See if you can measure the torque required to turn the pinion shaft now , then gradually tighten the nut , remeasuring the rotational pull until it produces the recomended restriction, I forget the # but it is only inch pounds on the bearing and will be in the shop manual, but many ft/lbs on the nut.

If that doesn't work for you , then you will just have to pull the diff apart and do the job properly.

First off I would get a new nut. These are self locking & lose there grip. Then tighten it down slowly till there is no play in the bearings. Then tighten it a little more till it gets a slight drag. Like Grigg says this is not rocket science but it,s worth a try. If it is not noisey it wll run for years. If it,s a little noisey & you don,t mind it will still run for years.
Just noticed. If this is a 3/4 ton there should be a cotter pin in it. Remove the cotter pin & tighten the nut very tight & tighten some more to get to the cotter pin hole. If the brg. is still loose you will need to rebuild it.

Thanks for the good input. I've probably driven 2-300 miles before I changed the transmission and noticed the loose nut. Here's what I think I'll try.

Remove the wheels and tires and tighten the nut until the rotational pull is at the upper end of it's spec. Maybe the upper end will compensate for the drag of the axles. Then tighten to the next cotter pin slot.

It's a 4.56 so I want to drive a few miles to see if the 0.72 overdrive gets me around OK. I'm not planning on doing any freeway driving with it. If it's OK then I may pull it out to check it properly. If it's not I'll run it till I find a lower ratio pumpkin.

I also just installed 3 point seat belts, if they work out I'll take some photos when I take them and the seats back out to paint.

If you have a front loading 3/4 Ton, 4:57 rearend, the pinion nut has nothing to do with bearing preloads at all. The nut does take a whole lot of torque though and a cotter pin.

I found that out today. It has 2 tapered bolts thru the case which hold the other side of the front bearing. So I torqued it and put in a new cotter pin.