Studs breaking off

[t160hq]

My brother called me tonight and he has one weird problem.

A 95 GMC Vandura 3/4 ton van is what we are dealing with.

The problem studs on the drivers side rear whell breaking off.

First time was about four thousand miles ago. 4 studs broke off and only 1 was holding the wheel on when he found out it happened. It was on a long trip (400 miles) when it happened. Thought it was a freak thing. Since he had just bought the van he figgured the last mech who replaced the tires got a little too overzelous with the air gun. Replaced the studs put the wheel back on and good to go.

No warning at all. No noise just popped off one by one until just one was holding the wheel.

Another long trip. Same story same wheel. Since then snow tires came off and were replaced with summer tires.

So just what can cause studs to break off. Since it happened he has checked the wheel berring and it does show some wear ( a slight bit of play up and down and side to side). Axle seems fine. The current plan is to change the wheel bering and axle. But this is more a can't think of anything else that would cause it than a Ahhh that's the problem sitituition.

So far this has stumped everyone we have talked to. No one can suggest anything short of this happens a lot with overloaded semi's. The family with assorted luggage in a 3/4 ton van hardly seems like overloading.

Currently in the bordering an the relam of off the wall ideas of the axle worn just right to produce harmonics that are just right to break metal.

Any idea's out there? Or has anyone run into this before?

t160hq

[mopar611]

Bad rim?

Brakes heating up studs?

Bad wheel bearing heating up studs?

[Bow]

I am going with the bad rim. If they are custom rims - rotate them and check often.

[mopar611]

I just got to thinking t160. I bet ya now its a bad rim. Not only causing bad breakage of the studs but also tearing up wheel bearing. With a 3/4 ton probably wouldnt notice it. Tell your brother to take it down to the tire shop and have it looked at. Mopar

[t160hq]

Rims were already changed. He had it happen with two different set's of rims. One for the snow tires and one set for the summer street tires. No specialty rims for him. Just the orginal GM rims. Both on the winter and summer tires.

mopar611 he's just like me in that respect. DIY all the way on any car repairs. If we don't have the tool for the job we know someone who does.

t160hq

[mopar611]

You never said if it was a full floating axle? Mopar

[ghost71799]

You never said if it was a full floating axle? Mopar

There are balance weights on drum and disk.

Axle's have a balance to them also.

Ghost

[mopar611]

Good point ghost! Its gotta be a vibration problem. Just gotta find it. Mopar

[BirdieMod]

Sure that is not a FORD.. Mine was recalled 4 times now for lug problems and the drivers rear wheel still came off with the replacements about 3 months ago at 70 MPH.

Thats Drum brakes on the back on that so heat cannot be the problem. It has to be something letting them shift or move somewhat, If the lugs were heated with a torch the temper of them may have been changed making them softer or brittle possibly.
I would take a look if they had recalls on it for any info. If this has alum rims make sure they are not wobbled out and the lug nuts themselves are the correct ones.

[t160hq]

Update found it. Took some doing but no doubt.

Well he pulled the axle in the process of changing it. Took it down to a good buddy who runs a garage near by. They set it up to check for warps in the plate that holds the studs.

Sure enough it was warped. Not enough to show visually or even cause vibration that could be felt. Short trips no problem take it on a long trip and the vibration showed up in the form of breaking studs.

Good call Ghost and mopar611. No doubt a vibration problem. Read your post and passed the info along and hence the trip to the friend with the proper diagnostic tools. Sure enough problem solved.

t160hq