Rattle/Scratching noise from the Transmission(Updated with video)

[Solo_M_Tech]

Ok fellas, I upgraded some transmission hardware the other day. Dinnan short shifter, cdv delete, and uuc blue street/track transmission mounts. As expected I have more transmission noise in the cabin. However, I've noticed a
Scratching sound. Like bolts in a can when driving at low speeds in any gear. No noise when still. It doesn't do it every time and is amplified when I shift. But then goes away. I understand these transmissions can exhibit gear chatter when using a single mass flywheel, but mine is stock. I've done some research and I believe this noise was there before, but the sound was being absorbed by the stock soft mounts. I'm looking for alternative opinions. I'm gonna have my service tech Flo take a look and listen. Give me your input.

[Pig Farmer]

I suspect it's the DMFW rattle exaggerated by the firmer tranny mounts. When you turn the car off (in neutral) does it rattle for a second or two as the engine shuts down? A lot of people get this rattle after the CDV mod. I sometime get a bit of rattle when driving in first gear while on and off throttle. What is strange is if the rattle persists while driving at a constant speed in a taller gear after the clutch is fully released.

[Solo_M_Tech]

I only notice it in first or second gear on slow driving (less than 30 mph) or third at the same speed on deceleration. It's not consistent, and wasn't noticed for a couple days after the parts were installed.

[Solo_M_Tech]

Ok i wanted to update with the solution. When i installed the mounts, i tightened the mounts down, and then the bracket. Which caused it to twist slightly. I loosened everything up, set the bracket back to it's original position ( I could see the discoloration on the aluminium) then tightened down the trans mounts. Everything is working good, no noises or weird vibrations.

[Solo_M_Tech]

I wanted to re-update this thread.... So after adjusting the mounts, the noise went away for about 2 days. I can definitively say it's transmission related. I get the scratching, rattling noise in all gears, acceleration, deceleration, and in Neutral when coasting to a stop. It's audible to anyone in the car. Some days it's worse than others. My car still has the stock trans fluid, clutch. Car has 27k miles, no clutch slip. I've done everything I can to narrow it down, and I have no idea what it is. Turner Motorsports is telling me it's gear chatter made audible buy the race trans mounts. Didn't notice the noise prior to installing them either, but is it damaging to the transmission? Do I need to do a transmission fluid flush?

[Dackelone]

You could put the old "stock" trans mounts back in and see what happens? IF the noise goes away... its your rear trans mounts.

[Solo_M_Tech]

Dack this is true. I want to make sure this isn't something else before I pay for another half hour of lift time to swap them out again.

[Zesinlijn]

Hello!

Found this topic after searching the internet! My car (e91 n55 335i) started making the same noise without any reason. In All gears with light throttle, clutch in or clutch out and even coasting in neutral. Bmw dealer said transmission needs to be replaced so i have put in a refurbished one in myself with a friend. Noise was gone but now one week later ithe same grinding noise is back. I have no clue what is causing this noise.. transmission mounts are new, clutch and dmfw is new (oem parts). Any idea? Thanks for helping me

[RayE82/135is]

I have the same exact noise on my 2013 135is msport manual transmission. Car is fully stock the noise started to happen a month or so ago. Car has 87k miles it drives and accelerate fine its just noisy. If any of you guys figures it out please give us heads up and same for me if I find anything out I will share it.