2007 GMC Envoy Body Ground Cleaning

I’m not sure what it will take to convince me that the transmission is actually bad in my GMC Envoy, but I refuse to believe that it is a mechanical failure.  As stated in this post, I’ve done a whole bunch of things to try and resolve the hard shift into drive issue but have been unsuccessful.

This time I’m thinking that it may be electrical, as in the actual wiring that is going to the electronic controller.  Since I don’t plan on dropping the actual transmission, I just jacked the truck up and felt above the transmission where the wiring is.  I just kind of ran my hands along the outside of the wiring to see if there were any obvious cracks or breaks in the lines.  Since it is wrapped in wire loom, it is hard to tell but there did not seem to be any excessive rubbing or worn areas.

Since that seemed ok, it led me to the ground point that is pigtailed off the main wiring loom in that general area.  It is on the outside of the frame rail just underneath the driver’s side door.  There is one grounding point there.  Of course I did not take a picture of it while it was intact, but it is a 10mm bolt.  Below is its location……minus the bolt…..

As you can see in the picture, there is no longer a lot of metal to metal contact since rust and dirt have taken over.  This will need to be cleaned, but first we need to repair the mounting point.

If you look closely, you can see the threaded half of the bolt still in place!  That’s because it was rusted solid and I snapped the head right off!  I didn’t even pull that hard!  Unfortunately, when you are working on older cars, this is going to happen so be prepared!

I busted out my trusty 3/8” drill and went to work.  Using a random bit that was just slightly larger than the broken bolt, I drilled out the rest of the bolt so there was a straight through hole.

Drilled Out the Bolt!

I then went and found some random bolts that would serve the purpose of making a tight connection for the ground.  I used my imagination and a couple of nuts and washers to put something together with what I had laying around.

Using the drill and a round brush attachment, I cleaned the location of the ground on the frame rail.  This you will want to take down to bare metal so there is metal to metal contact with the grounding wire. 

Clean Ground!

I also used the same attachment to clean the “washer” for the ground wire.  I just held the locking clip in my hand and was very careful not to wire brush my hand with the drill. 

Once complete and I was convinced that there would be good metal to metal contact, I used my bolts that I found lying around and bolted it all back together.  At the moment, this did not resolve my issue.  It may take a bit of driving around to get it back to normal, but I would have expected and instant fix.  Maybe this will actually convince me of a mechanical failure…..

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