I've done a bit of searching on this topic, and there is lots of information, but the cars discussed are newer than the 1989 I have to deal with, so I am unsure....

I have a bad wheel lug stud on the front of a 1989 cavalier. Do I really have to remove the hub unit in order to replace the stud? If so, are there any special tools needed, other than the large socket to remove the axle nut and something to separate the ball joint? Thanks!

I've never replaced a stud with the bearing on the car like that, I've always just taken the bearing right off and changed the stud out on the workbench. I will say this- your 1989 is exactly the same. I'm not sure why he pulled the bearing away from the spindle like that other than he couldn't turn the axle to get the broken stud hole over to the side of the spindle where the caliper mounts (thereby eliminating the need to remove the bearing from the spindle, since there is enough room to get the stud in, versus the other side, where the spindle is in the way). But, if you're going to go as far as pulling the bearing out of the spindle, why not just take it all the way off and put it on the workbench? You don't need to separate the ball joint to do any of this, the only things you need to remove are the axle nut (30mm), and the three T55 Torx head bolts holding the bearing to the spindle. You might need a chisel to separate the bearing and spindle, depending on how long it's been in there. The only other thing I question is throwing a wheel back on to pull the stud in. The normal way is to turn the lug nut backwards so the flat side is in and tighten it down that way. Then you don't run the risk of damaging the conical seating surface of either the wheel or the lug nut.

Hope that all helps you.
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Thanks a lot for your reply.

James Cahill wrote:I've never replaced a stud with the bearing on the car like that, I've always just taken the bearing right off and changed the stud out on the workbench. I will say this- your 1989 is exactly the same. I'm not sure why he pulled the bearing away from the spindle like that other than he couldn't turn the axle to get the broken stud hole over to the side of the spindle where the caliper mounts (thereby eliminating the need to remove the bearing from the spindle, since there is enough room to get the stud in, versus the other side, where the spindle is in the way). But, if you're going to go as far as pulling the bearing out of the spindle, why not just take it all the way off and put it on the workbench? .

I just included that link as an example of the information that is out there, I am not vouching for the accuracy or prudence of how that poster did things. His pictures and comments are much appreciated, though!

James Cahill wrote: You don't need to separate the ball joint to do any of this, the only things you need to remove are the axle nut (30mm), and the three T55 Torx head bolts holding the bearing to the spindle. You might need a chisel to separate the bearing and spindle, depending on how long it's been in there. .

OK. Some of the procedures I have seen call for the ball joint to be separated, but that might just be for work that goes further than simply replacing wheel studs.

James Cahill wrote:The only other thing I question is throwing a wheel back on to pull the stud in. The normal way is to turn the lug nut backwards so the flat side is in and tighten it down that way. Then you don't run the risk of damaging the conical seating surface of either the wheel or the lug nut. .

I have no intention of seating the studs by mounting the wheel.

James Cahill wrote:Hope that all helps you..

It does. I guess I now just have to dig into it and figure it out.