Ground Stud Nut over torqued

[aerodyne]

Consider running a wire to the steel ground stud on the right top side of the bumper frame...at least that is where it is on my pre refresh MS. For a more stock look, consider a plated or stainless blind rivnut in the existing ground stud location, to avoid drilling the other side of the frame (think blind rivet, one side access, but with threads you can put a bolt in)

 

[David.85D]

Joined the club this week. I've had an intermittent headlight and the darn car alarm has been going off randomly (and it gives a frunk is open warning when its not) waking everyone up. Started to investigate and found this broken off... Will try to drill and tap. If that doesn't work, will rivnut it...

 

[David.85D]

Drilled it and tapped it for an M6 bolt, cleaned the connections with a stainless steel wire brush and slathered everything in anti-corrosion grease.... Hope that's good for another 4-5 years...

 

[tga]

Thanks for the thread, @mrElbe! I guess this is more evidence that (early?) Teslas are CA cars not designed for, or built with thought given to, areas that see real winter weather and salt use. Thanks Elon.

My turn to join the club. I ignored the intermittent failures over the past month or so. Last night I had to get towed home after they returned and the car switched itself into neutral and wouldn't go back into gear or park.

I pulled the frunk and found the driver's side stud hanging on by a hair. A jumper between it and another stud clear everything (and allowed the car to go into park and then sleep). I'll drill and tap once the heat wave passes.

 

[mrElbe]

Thanks to all for the encouragement. After 4 years my repair is still working well.
For more of my 'repairs" take a look at my website: Repairs

 

[David.85D]

Thanks for the thread, @mrElbe! I guess this is more evidence that (early?) Teslas are CA cars not designed for, or built with thought given to, areas that see real winter weather and salt use. Thanks Elon.

My turn to join the club. I ignored the intermittent failures over the past month or so. Last night I had to get towed home after they returned and the car switched itself into neutral and wouldn't go back into gear or park.

I pulled the frunk and found the driver's side stud hanging on by a hair. A jumper between it and another stud clear everything (and allowed the car to go into park and then sleep). I'll drill and tap once the heat wave passes.

A small word of caution. Try to limit how deep you drill as the bit will go into the wheel well and it would stink to drill into your tire, brake line, etc.

just take it easy….don’t need to sink the whole length of the twist drill…

 

[tga]

A small word of caution. Try to limit how deep you drill as the bit will go into the wheel well and it would stink to drill into your tire, brake line, etc.

just take it easy….don’t need to sink the whole length of the twist drill…

I assumed the frame rails are hollow, and there was only ~1/4" or so to drill through before punching through to the hollow center?

 

[David.85D]

I assumed the frame rails are hollow, and there was only ~1/4" or so to drill through before punching through to the hollow center?

all that is true. I recall one side was on the strut tower and not the frame rail, but I’ve also had one of the bolts in the wheel area sieze, and had to drill that one, too, so my memory could be betraying me.

 

[tga]

The driver's side stud was badly corroded and twisted off with minimal torque. I definitely think galvanic corrosion and winter salt spray is the major issue, also high current through this stud (five ring terminals including the power steering pump). The passenger side (only 2 ring terminals) looks to be in good shape.

Original stud is an M8. The local hardware store had no brass metric hardware at the local store, so I drilled and tapped for 1/4"-20 bolt.
I cleaned up all 5 terminals (separating the interlocking pairs) w/ 400 sandpaper and resembled it with NoAlOx on the brass threads of the bolt and aluminum threads I cut, and also between the face of the frame rail and the bottom ring terminal. Before I put the tub back in, I slathered both terminals with silicone dielectric grease to (hopefully) keep the salt off.

 

[dark cloud]

The driver's side stud was badly corroded and twisted off with minimal torque. I definitely think galvanic corrosion and winter salt spray is the major issue, also high current through this stud (five ring terminals including the power steering pump). The passenger side (only 2 ring terminals) looks to be in good shape.

Original stud is an M8. The local hardware store had no brass metric hardware at the local store, so I drilled and tapped for 1/4"-20 bolt.
I cleaned up all 5 terminals (separating the interlocking pairs) w/ 400 sandpaper and resembled it with NoAlOx on the brass threads of the bolt and aluminum threads I cut, and also between the face of the frame rail and the bottom ring terminal. Before I put the tub back in, I slathered both terminals with silicone dielectric grease to (hopefully) keep the salt off.

Thanks for the reminder for me to go check mine; it has been a few years since re-attaching.

 

[Jillmark99]

2 weeks ago my right headlight started failing. So I ordered 2 HID D3S bulbs on Amazon and scheduled to tackle that job this weekend. The last Wednesday I get "Coolant low" message. Made appontment with Tesla service but was assured not to worry - probably a bad ground. The I got intermittent 3 beeps with a message flashing on the IP and main screen but not long enough to read. Also "Suspension needs service popped up frequently. I got worse yesterday while driving in the morning. In summary the following happened intermittently:

- message: Coolant low ( just when starting car )
- right headlight not working
- right turn signal intermittent ( for about 20 minutes, then working)
- message: Suspension needs service ( on permanently until full power off, then re-appearing)
- message: front trunk lid open (this was the 3 beeps and message happening frequently)
- phone notification: Car alarm has been triggered

I thought that there must be some commonality to this, like a bad ground. I removed the Frunk tub and Voila! a broken ground lug / stud merrily swinging in the air. Looks like too much torque was applied at the factory.

View attachment 216361

View attachment 216360

Drilled into the broken stud and tapped a thread
View attachment 216362

Then sandpapered the stud and brass lug connected to the 2 wires. Temporarily connected a jumper cable to the brass lug and low and behold the headlight worked and all warning messages disappeared.
View attachment 216363

Went to Hindle's Hardware in Clarksburg Ontario ( that is in the area where I was visiting ) and got a brass bolt with 2 nuts and special electrical paste for joining dissimilar metals. Reason for brass bolt is that the lug on the 2 wires was already brass.

That Hardware store is amazing! Right out of the 30's complete with crank cash register. If he doesn't have it then it doesn't exist.

Here is the finished job. All problems were solved by this including the malfunctioning headlight.

View attachment 216364

Total cost of repair CAD$ 5.20 ( and 2 beers and my time )

I had the exact same symptoms as OP happen to my Model S 2 days ago. I was worried I was in for a big repair. I found this post and pulled my front trunk out today and noticed the pass ground bolt corroded too. Drilled and tapped a new 1/4-20 hole, cleaned the corrosion and secured with a new brass bolt and it’s good as new. Quick and easy fix for less than 5 bucks.
Great article for the DIY person.

 

[dark cloud]

I had the exact same symptoms as OP happen to my Model S 2 days ago. I was worried I was in for a big repair. I found this post and pulled my front trunk out today and noticed the pass ground bolt corroded too. Drilled and tapped a new 1/4-20 hole, cleaned the corrosion and secured with a new brass bolt and it’s good as new. Quick and easy fix for less than 5 bucks.
Great article for the DIY person.

What year do you have?

 

[Jillmark99]

2015

 

[tekknoschtev]

Adding another successful repair thanks to this thread. I was anxious about the expensive repair bill. I was linked here by David.85D after posting the frunk sensor issue - and low and behold, the little bolt was the culprit! Thank you for such a well documented fix!

 

[Hobz]

Thank god I found this post! I've been at wits end trying to figure out the frunk/low coolant warning, lack or horn and highbeams for over a month. I still had warranty, but because I managed to tear my bumper off in some snow a few weeks earlier the service center told me they wouldn't touch the issue until I'd gone through insurance and an auto body shop in case it was related. Thanks to this thread all is fixed (pass side stud fell off as soon as I touched it) and I've avoided all the driving and insurance hassle! Now I'm pissed at Tesla because if it's this common of a problem they should have known they're not related. For reference, '15 85D, 70k. I'm now eyeing the d.side stud which is also quite corroded, but I didn't have the energy to fix that so I just slathered it with dialectric grease for now.

 

[Jillmark99]

Just an FYI for everyone.

If the drivers side ground stud breaks the car is not driveable. So if it looks corroded I would repair it before it leaves you stranded.

When the passenger side breaks the car is still able to drive.

 

[David29]

In recent weeks, I have had various combinations of the alarms for open frunk and the low coolant, issues with the right-hand headlamp/turn signal, and the car security alarm has sounded a few times. This thread helped me to realize that the odds are that it is a ground failure and not actually low coolant, which would be worrisome. The only intermittent problem that I cannot pin down is that sometimes when the car has one or more of these issues, the Autopilot also is not available for no apparent reason. I suspected the radar might be grounded at the same point because of its location. But the Tesla wiring diagram does not indicate the radar being grounded at the same point. So the Autopilot might be a separate issue.
Very glad to learn that Tesla has made their wiring diagrams and other service information available online for free!
Meanwhile, another week before my service appointment....

 

[Droschke]

In recent weeks, I have had various combinations of the alarms for open frunk and the low coolant, issues with the right-hand headlamp/turn signal, and the car security alarm has sounded a few times. This thread helped me to realize that the odds are that it is a ground failure and not actually low coolant, which would be worrisome. The only intermittent problem that I cannot pin down is that sometimes when the car has one or more of these issues, the Autopilot also is not available for no apparent reason. I suspected the radar might be grounded at the same point because of its location. But the Tesla wiring diagram does not indicate the radar being grounded at the same point. So the Autopilot might be a separate issue.
Very glad to learn that Tesla has made their wiring diagrams and other service information available online for free!
Meanwhile, another week before my service appointment....

Most definitely keeps us updated on what Tesla SC finds out.

 

[tga]

In recent weeks, I have had various combinations of the alarms for open frunk and the low coolant, issues with the right-hand headlamp/turn signal, and the car security alarm has sounded a few times. This thread helped me to realize that the odds are that it is a ground failure and not actually low coolant, which would be worrisome. The only intermittent problem that I cannot pin down is that sometimes when the car has one or more of these issues, the Autopilot also is not available for no apparent reason. I suspected the radar might be grounded at the same point because of its location. But the Tesla wiring diagram does not indicate the radar being grounded at the same point. So the Autopilot might be a separate issue.
Very glad to learn that Tesla has made their wiring diagrams and other service information available online for free!
Meanwhile, another week before my service appointment....

Curious what the "official fix" is - drill and tap, or something else?

 

[David29]

Most definitely keeps us updated on what Tesla SC finds out.

I have not yet received an estimate for this appointment, so i do not yet know what they think is wrong or what fix is expected.