Rear Sub Frame Bolt - It's not a big deal.
What you want to do is buy a front suspension bolt.

If you look at the pic, the bolt on the left is the current rear sub frame bolt. The one on the right is the front suspension bolt. It's a sledgehammer compared to the rear sub frame one. **The fix is that it comes with a washer and nut, you are "sandwiching" the sub frame to the frame of the car. I don't know why it wasn't done like this to begin with.
Also, this happens like you guys mentioned, from hard driving but most of all from launching the beast!
** R&D credit goes to my hero Shardul.
Am I being over charged? Lol they're saying it's time consuming and it'll be a couple days before it's done. But it's and hour job???
Also I have the cls63 model and they said this could have come from a pot hole or previous owner drive it hard which I highly doubt when everything is in excellent condition besides this one problem.



My warranty denies the claim on the basis that they do not cover bolts. Fine, its right there in the contract. They do however add that I should take it back to the shop that serviced the diff. They said that they most likely did not put the sub frame back together properly and the improper install lead to the bolt failure. They of course could not prove it but the tech said he is almost 100% sure as it is not the first time he has seen a broken sub frame shortly after rear end was dropped.
I took the car back to the shop that did the diff. Not only did I spend $35 on a new bolt from the dealer, I bought the tech the MOST expensive authentic German beer I could find in hopes they would have a soul and just help me assemble the new bolt. Boy was I wrong. After a week of finger pointing and complete BS, I just picked up my bolt (unfortunately they drank the beer) and started to look for a shop that would do the work.
I found a local shop down the street from Disneyland that did my diff and caused the bolt to break. The mechanic was absolutely a stand up guy and it took him all of 35 minutes to get the old bolt out and install the new one. He used vice grips and a wrench to pry the old bolt out and we did have to cut a small hole in the frame of the car to fit a washer and nut. They welded the hole back and took a grinder to it after. A+++ work and again it took him all of 35 minutes to do. The best part? He charged me $120!! I paid him and tipped his guy $30. I was thinking it would cost closer to $250 anyway. Which brings me back to the shop that butchered the install to begin with. Instead of just putting the car on a lift and attempting to tackle the problem, the owner just fed me a bunch of BS about who's to blame, how he doesn't have time, bla bla bla. This all knowing mechanic had no clue how simple of a job he was turning away. What could have taken 35 minutes of his time to right a wrong has instead earned him a disgruntled customer.
Also, big huge thanks to Shardul. I don't know where I'd be if he wasn't ready to troubleshoot problems any time day or night. Oh yeah, we live 1500 miles apart and I've never met the guy. That folks is a gentleman and a TRUE enthusiast.
Thanks,
Am I being over charged? Lol they're saying it's time consuming and it'll be a couple days before it's done. But it's and hour job???
Also I have the cls63 model and they said this could have come from a pot hole or previous owner drive it hard which I highly doubt when everything is in excellent condition besides this one problem.
Am I being over charged? Lol they're saying it's time consuming and it'll be a couple days before it's done. But it's and hour job???
Also I have the cls63 model and they said this could have come from a pot hole or previous owner drive it hard which I highly doubt when everything is in excellent condition besides this one problem.
I'm not saying the through-bolt and nut isn't "good enough", just pointing out the difference between the two approaches and why the cost is so much different.
The Best of Mercedes & AMG
I had the same problem happen to me where the passenger rear subframe bolt ripped out of the frame. My symptoms were a repetitive sound in the rear upon acceleration and the driver side rear wheel sitting lower than the passenger rear wheel.
It was a real pain to drill out the bolt, I used a Dremel tool to help cut it free. Thanks for the advice on this forum to help me fix this problem as I used the larger bolt recommended that is normally a front camber adjustment bolt. After I fixed this problem the noise I originally was having never went away and upon further inspection it appears that other parts of the subframe are having issues such as the front bushings being loose.
I have posted some pictures which look similar to other members picture but just wanted to add them for other people to look at who may be having the same problem. I always had problems getting the car to align correctly as well which could be partially responsible for the rear subframe being shifted out of correct possition.
What do you guys think?







My warranty denies the claim on the basis that they do not cover bolts. Fine, its right there in the contract. They do however add that I should take it back to the shop that serviced the diff. They said that they most likely did not put the sub frame back together properly and the improper install lead to the bolt failure. They of course could not prove it but the tech said he is almost 100% sure as it is not the first time he has seen a broken sub frame shortly after rear end was dropped.
I took the car back to the shop that did the diff. Not only did I spend $35 on a new bolt from the dealer, I bought the tech the MOST expensive authentic German beer I could find in hopes they would have a soul and just help me assemble the new bolt. Boy was I wrong. After a week of finger pointing and complete BS, I just picked up my bolt (unfortunately they drank the beer) and started to look for a shop that would do the work.
I found a local shop down the street from Disneyland that did my diff and caused the bolt to break. The mechanic was absolutely a stand up guy and it took him all of 35 minutes to get the old bolt out and install the new one. He used vice grips and a wrench to pry the old bolt out and we did have to cut a small hole in the frame of the car to fit a washer and nut. They welded the hole back and took a grinder to it after. A+++ work and again it took him all of 35 minutes to do. The best part? He charged me $120!! I paid him and tipped his guy $30. I was thinking it would cost closer to $250 anyway. Which brings me back to the shop that butchered the install to begin with. Instead of just putting the car on a lift and attempting to tackle the problem, the owner just fed me a bunch of BS about who's to blame, how he doesn't have time, bla bla bla. This all knowing mechanic had no clue how simple of a job he was turning away. What could have taken 35 minutes of his time to right a wrong has instead earned him a disgruntled customer.
Also, big huge thanks to Shardul. I don't know where I'd be if he wasn't ready to troubleshoot problems any time day or night. Oh yeah, we live 1500 miles apart and I've never met the guy. That folks is a gentleman and a TRUE enthusiast.




