2013 Silverado Ext Cab - Cab Bolt Spinning

JimboHD2005 · November 20, 2013

Hi Everyone,

I'm new to the forum though have been reading a lot of what seems to be a chronic issue with GM, spinning cab bolts when installing nerf bars or side steps. I picked up my new truck a couple weeks ago and just tried installing the bars. Using a hand ratchet, the front and middle drivers side bolts came out fairly easy.The rear bolt was extremely tight and after a few turns the bolt started spinning. I've seen in past forums that GM seems to know about the issue.

Is anything I can provide provide the dealer referencing the known issue so I don't get the "You broke it, it's not covered" speach? I saw a post in 2010 that referenced something that notified the dealer of the issue. Just was hoping for something to provide that was issued more recently (if any).

Any help here would be greatly appriaited. I can't believe the nut would break off so easily from the frame using a hand wrench. In seeing other posts it looks like the only way to fix is to drill a hole in the back of the cab to get at it so I'm praying this will be covered under warrenty.

Thanks again for the help!

Jim

JimboHD2005 · November 28, 2013

Thanks much for the replies! Thanks for the info!

CKNSLS · November 28, 2013

Some have had this covered and some have not.

However, for everyone else this is a great reason not to buy body bolt mounted nerf bars. There are several issues regarding body mount steps/nerf bars, this is just one of them. Buy the rocker panel mounted ones like OEM.

There are a few pots elsewhere that have stated some have got this fixed at a body shop for less than $200.00

here is the GM bulletin-

2010 Chevrolet Silverado - 4WD | Sierra, Silverado VIN C/K Service Manual | View All Bulletins | Document ID: 2535652

#10-08-61-001: Information on Body Mount Bolt Stripped or Will Not Loosen - (Oct 5, 2010)

Subject: Information on Body Mount Bolt Stripped or Will Not Loosen

Models: 2010-2011 Chevrolet Silverado

2010-2011 GMC Sierra

The purpose of this bulletin is to provide guidance to GM dealers when
performing repairs that involve the removal of the body mount bolts.
Technicians may discover that one of the cab mount bolts won't loosen
from the vehicle. The bolt may act like the nut is cross-threaded or no
longer secured to the floorpan of the vehicle.

The cab mounted cage nut may have bent or broken loose allowing the nut
to spin. If the nut is allowed to spin, it may prevent the bolt from
loosening. The front cab mount nuts are welded to the body structure and
are not involved with this bulletin.

The cage nut assembly must be accessed from inside of the vehicle if
this condition occurs. Some of the cage nuts have rectangular access
plates in the floor of the passenger compartment. These plates are
located above the affected bolt. On extended cab vehicles it is
necessary to create access holes in the rear floor area to reach the
rear cage nut.

Creating Access Hole (Extended Cab Vehicles Only)

Use the following steps to create an access hole in the rear floor area
of extended cab vehicles. This procedure only applies to the rear set of
mounting bolts.

Note: This procedure below is for the left side of the vehicle. The
procedure and measurements are the same for both the left and right side
procedures.

1. Remove the seat located above the affected bolt. Refer to Rear Seat Replacement in SI.

2. Partially remove (pull back) the floor covering (carpet) to expose the seat mounting stud area of the floor.

Object Number: 2531017 Size: SH

Click here for detailed picture of above image.

3. Apply masking tape to the repair area as shown.

Object Number: 2531019 Size: SH

Click here for detailed picture of above image.

4. Using a straight edge, create a line along the inboard side of the seat mounting studs as shown.

Object Number: 2531026 Size: SH

Click here for detailed picture of above image.

5. Measure and mark as shown (A), 10 mm (3/8 in).

Object Number: 2531027 Size: SH

Click here for detailed picture of above image.

6. Find the center point between the two mounting studs as shown. Create a second mark as shown.

7. Use a center punch to create a mark in the sheet metal.

Object Number: 2531028 Size: SH

Click here for detailed picture of above image.

8. Using a 1-1/2 in. hole saw, create an access hole as shown.

9. Service the cab mounting bolt and nut as required.

Object Number: 2531029 Size: SH

Click here for detailed picture of above image.

10. Coat the perimeter of the access hole with RTV Silicone Sealant,
GM P/N 12378521 (in Canada, 88901148) or equivalent, to seal the bare
edge of the metal.

Object Number: 2531030 Size: SH

Click here for detailed picture of above image.

11. Install the round body plug, GM P/N 15908858. Ensure that the plug is sealed with the silicone sealant.

12. Reinstall the floor covering and seat.

Cage Nut Access Using Rectangular Service Plug

Rectangular service holes have been provided in the floor of the cab to
access the cage nut in all other cab mounting bolt locations. The
service hole is directly above the cab mount bolt. Use the following
steps to remove and replace the service plugs that cover the service
hole.

1. Remove the seat located above the affected bolt. Refer to SI for the applicable seat removal steps.

2. Remove the sill trim plate. Refer to Front Side Door Sill Trim Plate Replacement in SI.

3. Partially remove (pull back) the floor covering (carpet) to expose the rectangular service plug.

4. Using a gasket scraper or similar tool, pry off and discard the rectangular floor plug.

Object Number: 2531031 Size: SH

Click here for detailed picture of above image.

5. Service the cab mounting bolt and nut as required.

Object Number: 2531033 Size: SH

Click here for detailed picture of above image.

6. Coat the perimeter of the access hole with RTV Silicone Sealant,
GM P/N 12378521 (in Canada, 88901148) or equivalent, to seal the bare
edge of the metal.

Object Number: 2531035 Size: SH

Click here for detailed picture of above image.

7. Install the rectangular body plug, GM P/N 15040085. Ensure that the plug is sealed with the silicone sealant.

8. Reinstall the floor covering, sill trim and seat.

Parts Information

Part Number

Description

Qty

15040085

Plug, Floor Panel Drain Hole (Rectangular Style Plug)

As Req.

15908858

Plug, Floor Panel Drain Hole (Round Style Plug)

As Req.

12378521 (in Canada, 88901148)

newdude · November 28, 2013

Don't know if it would be covered or not, but its worth a shot to see if GM will.

Side note...you could ditch the body mount mounted boards for a rocker mounted set, either OEM or aftermarket. Much better choice. Won't mess the cab mounts, cause any noises from messing with the cab mounts, etc.