WHEEL STUDS BREAKING ON PATROL

same wheel? Buckeled wheel? I kept snapping axle studs and it was due to a bent axle

Were the wheelnuts torqued up correctly by hand, or were they the usual "servo rattle gun" torque?

Rattlers can generate high instantaneous torque values, and are good for undoing stuck nuts/bolts, but they are capable of overtorquing for the same reason if used to tighten threads. This stretches the stud thread sightly and creates a "stress riser" at the hub to stud junction, alowing the nut to appear loose, leading to constant retightening, weakening the stud further until it eventually fails.

The solution is to use the supplied wheelbrace and place all your weight on it to tighten the nuts, DO NOT USE EXTENSION BARS. The manufacturers have probably worked out what torque is needed and supply the correct length brace with the vehicle.

Happens to all vehicles for the same reason.

Yep had the same problem a couple of weeks ago on my 2003 4.2 Patrol
Everyone on the forum gave me lots of reasons but it appeared to have happened before due to minor damage being evident under the car.
I noticed that the studs (5 out of 6) which broke were not original Nissan studs.
Have a search through the topics to find my original post.
As far as I am concerned there is something not right with the Nissan studs.
Never had this problem on any car before (including my Pajero and Defender), and I've been driving since 1972. If the torque etc. was incorrect I would have expected to have had this problem at least once before in all that time.

Have you changed the rims? I have seen the wrong nuts used on new rims. Steel rims use different nuts to alloy rims, the chamfer on the leading edge is different.

I had 2 wheel studs break off 300-400K after changing the LH rear wheel on my 2003 GU 3.0 TD. I posted the story on this forum.

Various experts provided all sorts of different reasons for the failure. I think I did everything correctly except for checking the tension after 20-30 K motoring. The dealer (and the manual) says that the nuts must be tightened to the correct torque.

My wheel was a write off according to the dealer due to elongated holes in the alloy rim. Replacement wheel was quoted at $900.00! I opted for a repair by a wheel and rim factory. This involved drilling out all the holes and utilising steel inserts. It sits on the back now but if I need to change a wheel on the road I will be checking the nuts regularly until I get them torqued.

Kings

This has been done to death.

Try a search for wheel studs and you should come up with a long list of suggested reasons.

I think it is unfair to blame Nissan for this one. There are so many possible causes and it has happened to many different vehicles. I have seen it on a 100 Series Yota and a Honda Accord.

I always think it is best to check the simple things first no matter what the problem. I have wasted a lot of money chasing big problems when a simple and easy check of the obvious would have found the problem a lot faster.

The torque on wheel nuts should be easy to check and cheap too. It should be about 80 foot pounds for the GU. The alloy wheels may be differen, but it should not need all your strength to do them up, it is easy to overdo it. Any Nissan dealership should be able to tell you what it is for sure.

If you are positive that the torque was correct then start looking for bigger problems.

Hope its simple cause anything else will be expensive.

Duncs

Ive done 500,000 ks in 2 patrols in 7 years, no problem... really come to think of it, no problems at all. Michael

Just went through both of my service manuals for the GU and they both list the same for Alloy & steel rims - 118 - 147 Nzm (12 - 15 kg-m, 87 - 108 ft-lb).

Hope thios helps.

Cheers,

Peter

I've got a brand new 05 4.2 GU and same problem.. mind you I don't have a torsion wrenchg so coul;dn't tell you what the torque was.. but snapped two studs. just putting the nuts on.. not real hard I know but the nuts weren't even up against the rim when the studs snapped.. And although I am not a bantam weight, I don't claim to be superhuman either.. Cost me two hours labour at my 'local' guy to remove hubs etc as they were both on a front wheel... not to mention the $80 nissan charge for 5 new studs...

Hi there
Whenever you do a wheel rotation- just put a smear of GREASE on all studs the whole length of the thread to the 'hilt'.

The biggest problem I find are those bloody rattle guns that mechanics use, now when I get new tyres fitted to either my hilux or commodore i ask them to do up nuts with wheel brace the cross type (fits 4 different sizes) not the rattle gun,have had 3 cross threaded studs due to the guns. Havnt had a problem since. Ive seen mechanics do up 10 ml nuts with rattle guns just pure laziness, or they use cordless drills to do up phillip head screws under the dash then wonder why they stuff them, sometimes better to do things yourself if you know how, at least you have taken care. regards steve

have a look and see if the thread has been cut too close to the brake hub, rememnber the weakes part of a bolt/stud is where the thread ends.......