Hub studs/nuts keep stripping

[TacoLand]

My rear hub studs and nuts keep stripping out before they get to 26-ft-lbs, figured I’d check here before I keep buying more studs and nuts.

Been trying to get the rear axle back together for two weeks now- 3 of the OEM original studs on each side were pretty mangled. Replaced them with spares, which stripped before getting to spec. Ordered 12 aftermarket studs cone washers and nuts to do both sides, 7 of those stripped before spec. Picked up some OEM studs and nuts from the local dealer and 3 stripped out just now.

I ran a tap through the hub threads when I was doing bearings, the studs thread in finger tight. Then I snug them with two nuts. Been installing cone washers, washers and nuts finger tight, then tightening by hand in a star pattern. They’ve stripped with both 3/8 and 1/2 in. torque wrenches, so unless they’re both suddenly inaccurate, I don’t think that’s it.

FWIW the cone washers on the rear axle have been a pain to get out each time I’ve taken it apart in the last few days, even after being cleaned/replaced.

Am I using the wrong procedure, just unlucky, or need to replace the axle/hub?

 

[robnicko]

Could be the use of a Tap in the threads can cut and weaken the threads. To clean the threads a chaser is best
is the nut stripping on the stud or stud in the hub?
Also, are you putting the studs in the correct way as they have more thread on one side compared to the other

 

[nukegoat]

You can drill and tap for 3/8-24, just need to through-hole the axle shaft with 3/8. They're hard and don't enjoy being drilled. Then you can ditch the stupid cone washers and use 12 points bolts or socket head cap screws

 

[jonheld]

My rear hub studs and nuts keep stripping out before they get to 26-ft-lbs, figured I’d check here before I keep buying more studs and nuts.

There is no torque spec for the studs screwing into the hub. They should be snug.
The 26 ft/lbs is for the nuts only, NOT the studs.

 

[mudgudgeon]

Post a photo of the axle flange with cone washers and nuts removed.

If someone has beaten the outer edge of the flange to remove cone washers in the past, the holes will be deformed. Once holes are deformed you'll always have problems.

Use a drift and hammer to strike the face of the flange beside/around the nuts, NEVER strike the edge of the flange.
At home, I use a piece of tube welded to an old SDS drill bit, place the tube over each nut and rattle nuts loose one at a time with my cordless SDS hammer drill set to hammer only. (or use an air chisel if you have air tools in the shop(

In the past, I've restored the tapered holes with the correct pitch countersink bit. Gently deburr. You don't want to take more material off than needed.

I've also used socket head cap screws in the past, but kept the cone washers.

I found bolt heads will protrude past the edge of the flange and interfere with wheel fitment, but admittedly, I tried 6 point bolts only

 

[mudgudgeon]

then tightening by hand in a star pattern

It's super easy to torque beyond spec just snugging these up by hand.

Its real easy to go past 26ft/lb on 6mm hardware!

 

[TacoLand]

Could be the use of a Tap in the threads can cut and weaken the threads. To clean the threads a chaser is best
is the nut stripping on the stud or stud in the hub?
Also, are you putting the studs in the correct way as they have more thread on one side compared to the other

The nut is stripping on the stud. Been putting them in long side into the hub, haven't had any issues on that side.

You can drill and tap for 3/8-24, just need to through-hole the axle shaft with 3/8. They're hard and don't enjoy being drilled. Then you can ditch the stupid cone washers and use 12 points bolts or socket head cap screws

Pretty tempting. I got annoyed last night and ordered some ARP studs, those are $$$$ for 8mm hardware. I know people move up to 3/8, have you had any issues with weakening the flange by drilling it out that much?

There is no torque spec for the studs screwing into the hub. They should be snug.
The 26 ft/lbs is for the nuts only, NOT the studs.

Like I said in the post: "the studs thread in finger tight. Then I snug them with two nuts." They're not going to 26 ft/lbs.

Post a photo of the axle flange with cone washers and nuts removed.

If someone has beaten the outer edge of the flange to remove cone washers in the past, the holes will be deformed. Once holes are deformed you'll always have problems.

Use a drift and hammer to strike the face of the flange beside/around the nuts, NEVER strike the edge of the flange.
At home, I use a piece of tube welded to an old SDS drill bit, place the tube over each nut and rattle nuts loose one at a time with my cordless SDS hammer drill set to hammer only. (or use an air chisel if you have air tools in the shop(

In the past, I've restored the tapered holes with the correct pitch countersink bit. Gently deburr. You don't want to take more material off than needed.

I've also used socket head cap screws in the past, but kept the cone washers.

I found bolt heads will protrude past the edge of the flange and interfere with wheel fitment, but admittedly, I tried 6 point bolts only

I'll snag a photo later today. Some of the cone washers go nearly all the way into the tapered hole, much farther than they typically do. Those aren't the studs that are stripping though.

For removal, I typically just give the stud a couple of whacks with a brass drift and hammer, they normally pop right out. A couple of these have been fighting me though.

 

[TacoLand]

I've also used socket head cap screws in the past, but kept the cone washers.

Do you still run this? Shouldered or fully threaded with the cone washers? Might make a run to the hardware store - some 12.9 cap screws are a whole lot cheaper than the ARP studs.

 

[jonheld]

Like I said in the post: "the studs thread in finger tight. Then I snug them with two nuts." They're not going to 26 ft/lbs.

FWIW, I just did this on the rear of my LX450. I had zero issues going to 26 and even a tad more. IMO, the hub studs and associated hardware are wear items and should be replaced once in a while. I replaced all 4 corners in 2017 with all new hardware.

 

[TacoLand]

FWIW, I just did this on the rear of my LX450. I had zero issues going to 26 and even a tad more. IMO, the hub studs and associated hardware are wear items and should be replaced once in a while. I replaced all 4 corners in 2017 with all new hardware.

Yeah, I agree. I just did the front axle and replaced those, too. No issues. Can't figure out what the deal is in the rear.

 

[mudgudgeon]

Do you still run this? Shouldered or fully threaded with the cone washers? Might make a run to the hardware store - some 12.9 cap screws are a whole lot cheaper than the ARP studs.

I used shouldered ones, still with cone and flat washer.
You can torque them a lot tighter, provided the thread in the hub is good

Edit. I did this on my hzj105. 105's had 10mm hardware, and I ran 35s and wheeled the piss out of it without issues

 

[SNLC]

Yeah, I agree. I just did the front axle and replaced those, too. No issues. Can't figure out what the deal is in the rear.

Studs wrong direction, flip them and try again.

Cheers

 

[TacoLand]

Studs wrong direction, flip them and try again.

Cheers

Are you saying the rears are supposed to go short-threaded end into the hub? I thought OE design was long threaded section into the hub?

Either way, I went with some cap screws and retained the cone washers so I could get this thing out of the garage.

I realize that this probably isn't ideal; the cone washers spin a little bit in the flange when installing and might cause some minor damage to the taper. On the other hand, the forces seem roughly the same as the OEM studs, and these don't strip out. Was able to back/pry the nut off one of the stripped studs, looked like this:

May switch back in the future. Idk. At least it moves for now...

 

[nukegoat]

Are you saying the rears are supposed to go short-threaded end into the hub? I thought OE design was long threaded section into the hub?

Either way, I went with some cap screws and retained the cone washers so I could get this thing out of the garage.

View attachment 3626072

I realize that this probably isn't ideal; the cone washers spin a little bit in the flange when installing and might cause some minor damage to the taper. On the other hand, the forces seem roughly the same as the OEM studs, and these don't strip out. Was able to back/pry the nut off one of the stripped studs, looked like this:

View attachment 3626074

May switch back in the future. Idk. At least it moves for now...

? Weird

Cause baby now we got bad studs?