Royal Screw Up - 2nd Row Seat Clamp Tightening Mishap (1 Viewer)

[ExpeditionMan]

Well... my first screw up on the '13 LX570... I sheared a stud on the seat rail near the innermost clasping mechanism on the passenger side 2nd row seat. I had been dealing with some squeaking/chatter as the seat slightly wiggled over bumps when unoccupied. After pulling off the trim pieces I revealed the seat rail, upon inspection the clasping mechanisms (72660F and 72650A) could be wobbled by hand. I determined tightening the nuts (blue circle/90179-08132) would pinch the clasping assembly slightly and therefore reduce the aforementioned play. The outermost side tightened down by a quarter turn, however the innermost nut sheared off in my hand almost instantly (red is stud location, blue is nut that was being tightened)... Of course the seat wobble is even worse than before and obviously this is not safe for a passenger.
I am currently looking through parts diagrams to determine if I am on the hook for a whole new seat rail assembly, an individual part, or if I can feasible drill out the stud and replace with a bolt/nut combo. Thoughts and suggestions are appreciated...

*Edit* looking at the parts diagrams I believe 72160 (green arrow) is the passenger side, rear seat rail for seats with a seat heater but no a/c. The parts website I am using does not hyperlink to a part but I was able to google and find (7216060120) which I believe is correct. Has anyone replaced the seat rail on their right rear seat before? Are there any other parts I'll need when replacing the seat rail?

 

[linuxgod]

Well... my first screw up on the '13 LX570... I sheared a stud on the seat rail near the innermost clasping mechanism on the passenger side 2nd row seat. I had been dealing with some squeaking/chatter as the seat slightly wiggled over bumps when unoccupied. After pulling off the trim pieces I revealed the seat rail, upon inspection the clasping mechanisms (72660F and 72650A) could be wobbled by hand. I determined tightening the nuts (blue circle/90179-08132) would pinch the clasping assembly slightly and therefore reduce the aforementioned play. The outermost side tightened down by a quarter turn, however the innermost nut sheared off in my hand almost instantly (red is stud location, blue is nut that was being tightened)... Of course the seat wobble is even worse than before and obviously this is not safe for a passenger.
I am currently looking through parts diagrams to determine if I am on the hook for a whole new seat rail assembly, an individual part, or if I can feasible drill out the stud and replace with a bolt/nut combo. Thoughts and suggestions are appreciated...

*Edit* looking at the parts diagrams I believe 72160 (green arrow) is the passenger side, rear seat rail for seats with a seat heater but no a/c. The parts website I am using does not hyperlink to a part but I was able to google and find (7216060120) which I believe is correct. Has anyone replaced the seat rail on their right rear seat before? Are there any other parts I'll need when replacing the seat rail?

View attachment 3024303

View attachment 3024305

View attachment 3024306

I can't see what the other side of the rail looks like where the bolt head is, but I'd think you could just use a screw extractor or worst case drill it out?

 

[ExpeditionMan]

I can't see what the other side of the rail looks like where the bolt head is, but I'd think you could just use a screw extractor or worst case drill it out?

So I believe the seat rail has a pressed stud, not a bolt. So there is nothing to extract. The nut circled in blue pinches 72660F as it fastens onto the stud from the seat track which you can barely make out in red. I'll try to get a better picture momentarily.

 

[ExpeditionMan]

A few more images to explain the situation. This is the outer side which is undamaged:

This is the inner side which had the pressed stud shear. Here are several images showing what I believe to be a pressed stud in the seat rail assembly based on FSM and parts diagram images. The red arrow shows where the threaded stud poked through (prior to shearing) and received the nut. The blue arrow shows the "pressed" head which is not removable.

 

[grinchy]

I suspect it was already sheared, and that's why it was wobbling in the first place. Might be a candidate to fix with a weld, use washers to span the welded/non threaded area, and resecure using the nut.

 

[ExpeditionMan]

I suspect it was already sheared, and that's why it was wobbling in the first place. Might be a candidate to fix with a weld, use washers to span the welded/non threaded area, and resecure using the nut.

I suspect you are correct that it was fatigued already if it broke this easily. I placed an order for 7216060120 and am anxious to see if it include the correct stud. If I had a welder to do this I might give it a shot. If it was more accessible cutting the stud and drilling for a new bolt/nut combination would work. However, by the time I disassembled for that I might as well just replace the part.

 

[linuxgod]

See if you can press it out (or just knock it out with a hammer and center punch). I'm wondering if it's something like this

Elevator bolts, Zinc plated steel - Bolt Depot

www.boltdepot.com

or more likely one of these

https://www.etrailer.com/Accessories-and-Parts/Reese/55055.html

 

[ExpeditionMan]

See if you can press it out (or just knock it out with a hammer and center punch). I'm wondering if it's something like this

Elevator bolts, Zinc plated steel - Bolt Depot

www.boltdepot.com

or more likely one of these

https://www.etrailer.com/Accessories-and-Parts/Reese/55055.html

You may be onto something here, something like this or the elevator bolt you posted. I'll wait for the part I already ordered to show up and confirm it's not welded in.

 

[ExpeditionMan]

I was able to find the seat disassembly process within the FSM, but it never details removal of the seat rails. Steps 14 and 15 show removing the seat hinges, but then proceeds to rear seat cover removal and further disassembly. Could be missing something though.

Maybe these steps, but hoping someone can shed light on the process.

 

[CanadianRockyCruiser]

Usually, when I shear a bolt, I like to weld a nut on top of it, and then back it off using a wrench. The location inside of the cabin, near plastic parts may not lend it self to amicable implementation of said technique. Drilling is certainly an option to remove the offending bolt, and that's probably the approach I would take at this point.

 

[CharlieS]

Hard to say with all the stuff around it. I'd disassemble as much as possible, if space allows grind off the back and punch it through with a hammer and punch, replace with a bolt trough the back, tack welded to the rail.

 

[bloc]

I’d be driving it out with a punch and replacing it with a bolt, likely with a little JBWeld under the head to hold it in place like the original bolt.

It is possible the original bolt isn’t welded but has a knurled section under the head to both hold it in place and prevent spinning when tightening the nut without needing to back it up with a wrench. Quick assembly.

 

[ExpeditionMan]

Well a punch and hammer did not work. I've placed an order for the rail, apparently there are only 2 in the country... should have it in hand within 12 business days.

 

[ExpeditionMan]

I began disassembling the seat in preparation for the rail to arrive. I took tons of pictures to document the process in case anyone has a need in the future. The seat rail is out of the vehicle!

Here is the stud exposed for the first time:

And a close up of the component.

 

[ExpeditionMan]

I am currently stuck here. The drive screw will not exit the rail assembly. I am outside any instructions from the FSM and assume the pins shown below punch out and release the screw. This would allow me to separate the damaged component from the rail assembly. However, no amount of hammering with a punch and a 2lb hammer would free it. So I am going to be patient and hope that the new part comes with the screw pre-assembled.

 

[bloc]

I began disassembling the seat in preparation for the rail to arrive. I took tons of pictures to document the process in case anyone has a need in the future. The seat rail is out of the vehicle!

View attachment 3025291 View attachment 3025281

Here is the stud exposed for the first time:

View attachment 3025283

And a close up of the component.

View attachment 3025284 View attachment 3025285

Not how I had pictured it in my head… thanks for detailed pictures to help others in the future.

 

[ExpeditionMan]

The ordered part is arriving tomorrow. Will update thread with image regardless of correct fitment or not.

 

[ExpeditionMan]

The part assembly has arrived! I have not confirmed fitment yet, however it sure looks correct. Even better everything is fully assembled and ready to go. This is going to be a direct swap if everything lines up properly. I'll update this thread with a resolution in case anyone makes the same mistake as me.

 

[ExpeditionMan]

I have not made the replacement yet, however I did take the opportunity to clean up the corrosion I noted in an earlier post on the seat bracket itself. The prior owner liked sugary drinks and must have spilled some soda. This caused the corrosion pictured. While preparing for the replacement seat bracket I sanded, primed, and painted the surface.

So this was the original condition:

Sanded and cleaned:

 

[ExpeditionMan]

Primed and topcoated: