The Welded Square Nut for the Cab Air Bags is Un-Welded.

[QLStar]

I was trying to change my cab air bags on "PoTater" . During the process of trying to get the bag to unscrew from the mount the square welded nut came un welded an now just spins. Any suggestions? How do I remove the air bag now? The hole in the end of the mount enclosure is only about 3/4 of an inch in diameter and too small to get a wrench into.

 

2007 VNL670

[RRoger]

While I don't know exactly, usually when things like this have happened to me my angle grinder usually comes into play. Other times you can use something like a sawsall to make a strategic cut.

 

Think about how to limit the damage to that which you were going to replace anyway or to something that will be cheap and easy to fix.

[phoenix2013]

Yes, a common "malady", with time the "weld-nut" rusts and the weld bond to the sheet metal breaks as you start wiggling the air bag. Here's how we "fixed it".

 

1. We hack sawed off the air bag stud, slow process and PITA but you'll get through it. Retrieve the "amputated" studs with nuts, or leave them in there if they "travel" further into the crevice, who cares.

 

2. Determined the thread on the new air bags studs and purchased two plain steel nuts to fit on those. I don't remember if these were metric or inch.

 

3. Spot weld short piece of wire (coat hanger size) to the nut so that you can maneuver it over the hole and thread the air bag stud into the nut while holding onto the wire. We actually left the wires in place sticking out a little, just in case disassemble was "needed in the future".

[Shallow Draft]

I cut off the old air bag and then drilled a hole about 1 inch in diameter to get a socket on the new nut. The extra hole I covered with good foam tape to seal out any material that doesn't belong in the sleeper storage area

[QLStar]

Yes, a common "malady", with time the "weld-nut" rusts and the weld bond to the sheet metal breaks as you start wiggling the air bag. Here's how we "fixed it".

 

1. We hack sawed off the air bag stud, slow process and PITA but you'll get through it. Retrieve the "amputated" studs with nuts, or leave them in there if they "travel" further into the crevice, who cares.

 

2. Determined the thread on the new air bags studs and purchased two plain steel nuts to fit on those. I don't remember if these were metric or inch.

 

3. Spot weld short piece of wire (coat hanger size) to the nut so that you can maneuver it over the hole and thread the air bag stud into the nut while holding onto the wire. We actually left the wires in place sticking out a little, just in case disassemble was "needed in the future".

First I want to thank everyone for their input on this subject. I decided to enlarge the hole in the back of the support and was able to get a wrench in to hold the broken nut plate. I used the mechanical fingers to put a washer on the stud and installed the nut. Had just enough room to use a wrench to tighten the nut. The other side came off after sitting for a couple of days with penetrating oil on it. Do you think I should change the leveling valve? It doesn't appear to be leaking but now would be the time if It is a concern. Thanks

[Hewhoknowslittle]

First I want to thank everyone for their input on this subject. I decided to enlarge the hole in the back of the support and was able to get a wrench in to hold the broken nut plate. I used the mechanical fingers to put a washer on the stud and installed the nut. Had just enough room to use a wrench to tighten the nut. The other side came off after sitting for a couple of days with penetrating oil on it. Do you think I should change the leveling valve? It doesn't appear to be leaking but now would be the time if It is a concern. Thanks

 

If you don't do it now, you wish you did when you change it later.

 

When I changed my cab and axle bags I changed the valves and air lines, the valves work while the truck is in motion and have as much wear or more than the bags, IMPO.

 

Roger

[QLStar]

First I want to thank everyone for their input on this subject. I decided to enlarge the hole in the back of the support and was able to get a wrench in to hold the broken nut plate. I used the mechanical fingers to put a washer on the stud and installed the nut. Had just enough room to use a wrench to tighten the nut. The other side came off after sitting for a couple of days with penetrating oil on it. Do you think I should change the leveling valve? It doesn't appear to be leaking but now would be the time if It is a concern. Thanks

 

Yes, a common "malady", with time the "weld-nut" rusts and the weld bond to the sheet metal breaks as you start wiggling the air bag. Here's how we "fixed it".

 

1. We hack sawed off the air bag stud, slow process and PITA but you'll get through it. Retrieve the "amputated" studs with nuts, or leave them in there if they "travel" further into the crevice, who cares.

 

2. Determined the thread on the new air bags studs and purchased two plain steel nuts to fit on those. I don't remember if these were metric or inch.

 

3. Spot weld short piece of wire (coat hanger size) to the nut so that you can maneuver it over the hole and thread the air bag stud into the nut while holding onto the wire. We actually left the wires in place sticking out a little, just in case disassemble was "needed in the future".

The nuts are metric 10X1.50, just for future information.

[phoenix2013]

First I want to thank everyone for their input on this subject. I decided to enlarge the hole in the back of the support and was able to get a wrench in to hold the broken nut plate. I used the mechanical fingers to put a washer on the stud and installed the nut. Had just enough room to use a wrench to tighten the nut. The other side came off after sitting for a couple of days with penetrating oil on it. Do you think I should change the leveling valve? It doesn't appear to be leaking but now would be the time if It is a concern. Thanks

Good move to let it soak for few days and avoiding doing TWO OF THEM.

We use the same valves on ETs and I would venture they get lot more "action" in an ET, I reworked my ET three times (improvements of the prototype) in eight years and reused the same valve, works fine. We buy them in bulk, but I think they are about $80 bucks over the counter at a Volvo dealer.