[pealer]

Took the 66 out for it's first drive in 7 years a couple of months ago and everything went fine for a week until I drove around a dead skunk in the road. When I came back into my lane it started shaking like crazy and when I got out to check what was going on I found 4 lugnut studs sheared out of the passenger side brake drum housing and only 1 lug left holding the tire on. Thankfully that 1 lug was there or things could have gotten really ugly. But while it was up in the air awhile ago I noticed the passenger side tire assembly would slide about 1l4" or so in out. I think when the car straightened out the sideways pressure of the tire sliding in and out popped them off. I posted this problem on here earlier but most said it was no big deal and not to worry so I didn't. Now I think it's time to address this problem and any ideas on where to start or look would be appreciated. I haven't torn the cover off yet, the car is in the U.S. and I am currently stationed overseas but I'll be back in a month and that is the first thing I am going to correct before anymore cruising is done. Thanks for any help or advice on what to check on.

[Black67]

If it was me, I would pull off the cover and check the c-clip. Look to see it is seated all the way, check the pocket that it sits in and is fully engaged.

At that point, I would pull the axle out and inspect it. For me, 1/4" play is a bit much. I would also check the play in the bearing.

Did you have all of the lug nuts tight, if you can remember? Also make sure that the brake drum is seated completely.

Is this for a 10 or 12 bolt?

Bill

[big gear head]

Need to know more about the rear end. Is it a 10 bolt or 12 boolt? Does it have an Eaton Posi or a standard differential?

If it has a Posi then the clutches need to be replaced or shimmed. As the clutches wear the axle end play will increase. When the clutches are shimmed for the correct preload there will only be about .005 to .010 inch axle end play.

If it has a standard differential and someone has been doing one wheel burnouts then the thrust washers behind the axle gears are probably severely damaged, along with the differential case. One wheel burnouts are very damaging to a differential. If this is the case then the differential might need to be replaced.

C clips can also wear, although the wear is usually very slight. The ends of the axles also wear slightly, but not enough to notice. The cross shaft will usually show slight signs of wear. If you add all of this together then you might have a little bit of end play from this. You need to get into the rear end and see what the problem is. If the axle end play actually is 1/4 inch then you have a problem. Usually 1/16 is nothing to worry about, but if it gets much more than that you need to correct it.

[pealer]

Thanks for the tips all. It's a standard 12 bolt posi carrier. All stock I haven't done any modifications to it or anything. I had all of the lugs tight I had just put the tires on a week before and all of the ones on the other tires were good. I just think that the side to side pressure of the tire and axle sliding in and out popped them right off. Are C-clips and or clutch packs hard to change? I've never done any rearend work and if it's something that's pretty complicated I'll just send it off to a shop or a quality home mechanic to have fixed if that is the problem. Thanks again for the tips.

[pealer]

Also, how is the correct method to measure the endplay? I imagine getting some of the little paper thin shim pack is the correct way but would like to know more about this. Thanks again.

Originally Posted by big gear head

Need to know more about the rear end. Is it a 10 bolt or 12 boolt? Does it have an Eaton Posi or a standard differential?

If it has a Posi then the clutches need to be replaced or shimmed. As the clutches wear the axle end play will increase. When the clutches are shimmed for the correct preload there will only be about .005 to .010 inch axle end play.

If it has a standard differential and someone has been doing one wheel burnouts then the thrust washers behind the axle gears are probably severely damaged, along with the differential case. One wheel burnouts are very damaging to a differential. If this is the case then the differential might need to be replaced.

C clips can also wear, although the wear is usually very slight. The ends of the axles also wear slightly, but not enough to notice. The cross shaft will usually show slight signs of wear. If you add all of this together then you might have a little bit of end play from this. You need to get into the rear end and see what the problem is. If the axle end play actually is 1/4 inch then you have a problem. Usually 1/16 is nothing to worry about, but if it gets much more than that you need to correct it.

[big gear head]

There are shims that go behind the clutches in the Eaton Posi. This is how you set the preload on the clutches. Having the preload set right will also reduce the end play on the axles. If the clutches are worn out then they need to be replaced too. If you need someone to do this for you I can help. I just finished one for a guy in VA. and will be shipping it back to him on Monday.

[pealer]

I may be taking you up on that offer, I plan on pulling the cover off the first chance I get to see what is going on so if there is a way to get ahold of you maybe send me a PM with details on how to do so should the need arise. Thanks again for the help I appreciate it. I can usually find my way through about everything else but have just never been inside a rearend and all it's intricate details.

[hpsherlin]

While you are at it, you might think about knocking all the studs out and replacing with new ones on all 4 corners.

[big gear head]

Send me an email at biggearhead@bellsouth.net and we'll talk about it.

[LeoP]

most likely the sideways thrust of the axle had nothing to do with the studs breaking off, fatigue and age are the most likely factors. Do as Fred(biggearhead) suggests and inspect and repair before driving again.

[Rich-L79]

Originally Posted by LeoP

most likely the sideways thrust of the axle had nothing to do with the studs breaking off, fatigue and age are the most likely factors. Do as Fred(biggearhead) suggests and inspect and repair before driving again.

Absolutely correct.

You also need to make sure the wheels fit snuggly down over the end of the axle protruding through the wheel stud flange. The back of the wheel needs to mount fully flush against the flange. If the hole in the wheel is too small, it will bottom out against the end of the axle before fitting down flush to the flange and subsequently put undo pressure on the wheel studs. The wheel studs aren't there to hold the car up, they are there only to hold the wheel on and the wheel should be supporting the car by mounting snuggly to the end of the axle shaft.

If you have aftermarket wheels which locate the wheel using long shafted lug nuts, make sure the lug nuts aren't longer than the holes through the wheel are deep or the lug nuts may bottom out against the axle before seating the wheel snuggly to the axle.

[pealer]

The wheels fit fine I made sure of that the lugs come to about the middle of the hole, the driver side fits just fine so it's def not that. And it doesn't move any it's set in place and doesn't slide either way so it seems like this is a passenger side problem only. I just have to figure out why.

[Rich-L79]

Originally Posted by pealer

The wheels fit fine I made sure of that the lugs come to about the middle of the hole, the driver side fits just fine so it's def not that. And it doesn't move any it's set in place and doesn't slide either way so it seems like this is a passenger side problem only. I just have to figure out why.

The in-out movement of the axle is worth investigating and correcting, but it alone does not explain why your lug bolt broke off. You need to figure that out as well.