Billet diff mount: 12.9 bolts

[SCD-1983]

Hi everyone

I’m in the process of purchasing a used RK Autowerks billet diff mount, unfortunately the bolts are not included.
Can anyone point me in the right direction regarding thread size and length?
There are 3 bolts in total, I’m also awaiting a response from RK directly.

Thanks 🙏

[TinCanSailor]

realoem.com is a great source for parts information. See below for what I found regarding the bolts. Make sure that you have a good bushing in the billet brace. It does use the OEM bushing but the bushing cannot be purchased as it comes assembled in the brace from BMW.

Diagram No:06
Description: Hex bolt with washer
Supp: M12X1.5X60-10.9
Qty: 3
Part No: 31126760203
Price: 2.47

https://www.realoem.com/bmw/enUS/sho...diagId=33_1616

[SCD-1983]

Originally Posted by TinCanSailor

realoem.com is a great source for parts information. See below for what I found regarding the bolts. Make sure that you have a good bushing in the billet brace. It does use the OEM bushing but the bushing cannot be purchased as it comes assembled in the brace from BMW.

Diagram No:06
Description: Hex bolt with washer
Supp: M12X1.5X60-10.9
Qty: 3
Part No: 31126760203
Price: 2.47

https://www.realoem.com/bmw/enUS/sho...diagId=33_1616

Thank you very much for the detailed response. In order to install this brace, special bolts are needed, they are longer and stronger. I contacted RK and I’m awaiting their response. And the bushing is included, it’s an OEM bushing.

[TinCanSailor]

Originally Posted by SCD-1983

Thank you very much for the detailed response. In order to install this brace, special bolts are needed, they are longer and stronger. I contacted RK and I’m awaiting their response. And the bushing is included, it’s an OEM bushing.

Great folks over there and they will surely get you sorted out. If you are installing this yourself; I seem to recall a bolt on the top of the diff that was an absolute pain in the backside to get out. Also, there are some tightening/torque specs and procedures that are important to follow which help reduce diff whine.

[SCD-1983]

Originally Posted by TinCanSailor

Great folks over there and they will surely get you sorted out. If you are installing this yourself; I seem to recall a bolt on the top of the diff that was an absolute pain in the backside to get out. Also, there are some tightening/torque specs and procedures that are important to follow which help reduce diff whine.

Thanks a lot for supporting me, a shop will most likely install the mount. By any chance, do you have the specs/procedures handy, so I can prepare the install and avoid diff whine?

[TinCanSailor]

I am out of town for work and won't be home for a while so I don't have the instructions. There is a website called newtisDOTinfo, replace DOT with a .

It does require a user account but it is free.

One other bit of advice there is a single use nut at the very back of the rear diff. I will see if I can find the part number for it in my email inbox.

[TinCanSailor]

I paid about 5 USD for mine, this is the part number 33306787062.

[SCD-1983]

Originally Posted by TinCanSailor

I am out of town for work and won't be home for a while so I don't have the instructions. There is a website called newtisDOTinfo, replace DOT with a .

It does require a user account but it is free.

One other bit of advice there is a single use nut at the very back of the rear diff. I will see if I can find the part number for it in my email inbox.

I have access to the documents and will look into it soon, as well as purchasing the single use nut ✅ thanks again buddy!

[TinCanSailor]

Happy to help. Keep us apprised of the progress.