DIY:MFactory Carbon Fiber Driveshaft Installation

[randrews15]

First, if you chose to use this DIY you do so at your own risk, and this isn't meant to cover all models and situations. I have included what I feel are helpful hints as I conquered this little project today. On a scale of difficulty from 1 being super easy and 10 requiring a professional, I'd say that this project falls into a 5 as it requires some special tools and lots of time. All in all, it took me somewhere between 4 and 5 hours to do and that included a stop at the auto parts store and a break for lunch. So let's start the DIY...

The first issue I had was jacking up the car. I recently added a carbon fiber front lip which made using my low profile jack not possible and my ramps weren't low profile ramps as well. So, I attacked in from the side and jacked it on the corner of the skid plate that I knew was over subframe. This allowed me to get the other jack under the front central jack point. From there I used the jack stands to secure the front and the rear eventullay





Your car should look like this once you're done and properly secured.


I'm running a full Akra Evo exhaust which had to be removed from the X-pipe back. There are some that may leave the muffler on, but I found it easier to do it this way and gave me room to work without worrying about the mufflers.



Next, you will need to remove all the heat shields, and if you have a DCT, I recommend removing the skirt for that as well. There was no way to access the flex disk bolts without removing it for a DCT, and more on that later when we tighten everything up. Make sure you use a jack and a block of wood to support the DCT as this will make installation easier by jacking the DCT up a smidgen.





With all the heat shields removed and the DCT mounts out of the way you should be looking at this. According to TIS, you should disconnect the flex disk first before loosening the diff bolts and then the center bearing bolts. I ended up removing the flex disk with the drive shaft as it made it easier since the bolts are really tight and very little room to work. All of the bolts and nuts are 18mm at the flex disk and I found a ratcheting wrench helps a lot here. The diff bolts are a E12 and are really tight and the top bolt was a PITA. After the bolts are out then pry the CV joint out with a screw driver at the recessed points and then loosen the center bearing. Once I did all that, the drive shaft pretty much just fell out on its own.


I compared the two and they seem to be pretty much identical. Now, when you attach the flex disk to the new drive shaft I found that a socket won't fit on the drive shaft end of things due to the design of the flange. This maybe perceived as a design flaw; however, I worked around this by using a socket on the opposite end and a open ended wrench on the flange side. I had to use my son to brace the opposite end of the drive shaft as I torqued the flex disk nuts, I bought new nuts, and eventually added what I believe was close enough to an additional 90 degrees. At this points I used Rostbeef's recommendation of TAF for a final torque spec.

Install the transmission end first with the help of someone else and I ran the bolts through the flex disk to the output shaft of the DCT. I found that this kept things lined up while I worked the other end. This is where jacking up the DCT helps create clearance that you will need to slide the CV joint into place. When lining up the drive shaft to the diff, it requires some patience and I spun the diff to help line up the bolt holes. I reused the bolts and opted not to use the green loctite as suggested. I was able to get a 3/8 torque wrench in there and added what I believe was an additional 45 degrees as recommended. To be honest, I don't know what loctite would do because those bolts are super tight now.


With the redesigned flange there is no way a 18mm socket will fit onto the flange side or on the DCT side. I found two 18mm wrenches were ideal for tightening, and this is where a ratcheting wrench makes things easier. Be careful tightening as I dropped wrench on my forehead which probably frightened the neighbors with my language. Again, I used TAF torque specs as there is no way to get a torque wrench in there as suggested.


You should now be looking at this once everything up bolted as TAF and the DCT mounts back in place. Once you get to this point it's a matter of reattaching the heat shields and reinstalling the exhaust. MFactory recommended heat wrap, and while I ordered some which hadn't come yet, I'm not sure what good it will do since the entire drive line is covered by the heat shield. Plus, the titanium of the Akra setup dissipates heat differently than steel does.

Impressions: Once everything is buttoned up and the car lowered, it's now time to take it for its maiden voyage. I immediately noticed a more direct feeling with the drive line. Frequently, I would notice some lag before engagement and some clunk, but now that is mostly gone and acceleration is almost instant. I went easy at first to warm up the motor and to hear for any weird sound such as NVH. I didn't notice nothing weird or any NVH, but I am running stock bushings so that may help with that. Once the car was up to temp it was time to push the envelope. On the first near full throttle acceleration I noticed that the the car revs much quicker. It's likely due to less rotational mass with that power being transferred to the rear wheels. I did two more near full throttle runs and I found shifting better than the stock drive shaft and again the revs came on quicker. Certainly, this has to be one of my favorite mods so far, and I've done a lot to this car (Macht Schnell stage 2 air intake and under drive pulleys, Alpine motor sports stage 2 tune, and Akra Evo exhaust).

MFactory made a quality product and its build quality is second to none in my opinion. It will be interesting to see how long this last since this is a Gen 2 drive shaft. On a funny note, my wife had asked me when it came why I needed a new drive shaft for the M? I promptly told her that it's lighter and less rotational mass will make the car more fuel efficient to help save the polar bears. She just shook her head at me and said I love you as she walked away. I did marry the right gal in my mind. If anyone has questions, please feel free to hit me up and good luck to the rest of you about to do this project.

[serranot]

Thanks. Great write up. Looking forward to getting mine installed.

[NRBRNG]

Great. Thank you,

[ebisu8]

Nice work! It's a pretty straight forward install once you have everything off. Jacking up the transmission is key to make everything slide right into place. I wrapped mine at both ends just in case. just a little extra piece of mind I guess.

[roastbeef]

Originally Posted by randrews15

At this points I used Rostbeef's recommendation of TAF for a final torque spec.

aaah, now i remember why i reverted to the TAF standard... i couldn't fit my torque meter in there.
i don't have a legit torque wrench. i use an ac delco torque meter that goes between the ratchet and socket. it has a tiny bit of play, so its not good for tight places or limited rotation.

[randrews15]

Originally Posted by roastbeef

aaah, now i remember why i reverted to the TAF standard... i couldn't fit my torque meter in there.
i don't have a legit torque wrench. i use an ac delco torque meter that goes between the ratchet and socket. it has a tiny bit of play, so its not good for tight places or limited rotation.

I thought that was a nice way to pay homage to your advice. I have a legit torque wrench and a angle torque meter and neither could fit in there with the new driveshaft. I don't foresee it as a problem as long as people tighten it up as much as possible.

[pbonsalb]

With an extension, you might gain the clearance to use a torque wrench. Of course the extension and the angle on it needed to get the clearance reduce the accuracy.

[amrazM]

The socket not fitting was such a pita, I grinded an 18MM to get it to fit.

[Silverstoneorspacegray]

I know I don't need this but boy do I want it

[GORDON.M3]

Originally Posted by Silverstoneorspacegray

I know I don't need this but boy do I want it

At first, I thought the same thing, after getting it... man does the car feel completely different. More direct, and predictable.

[Silverstoneorspacegray]

Originally Posted by GORDON.M3

At first, I thought the same thing, after getting it... man does the car feel completely different. More direct, and predictable.

ugh stop it. I keep coming back and looking at this

[randrews15]

Originally Posted by Silverstoneorspacegray

ugh stop it. I keep coming back and looking at this

Just go ahead and get one. You certainly won't regret it I promise.

[randrews15]

Originally Posted by Silverstoneorspacegray

ugh stop it. I keep coming back and looking at this

Just go ahead and get one. You certainly won't regret it I promise.

[GORDON.M3]

Originally Posted by Silverstoneorspacegray

ugh stop it. I keep coming back and looking at this

you already have ohlins lol the DCT shaft is just a small fraction of the price to make the car so much better...

[bmwm3s65]

Originally Posted by amrazM

The socket not fitting was such a pita, I grinded an 18MM to get it to fit.

How did you modify the socket? did you shorten the hight, thin the socket wall?

[bmwm3s65]

Randrews, did you have to balance the carbonfiber driveshaft?

[randrews15]

Originally Posted by glacket

Randrews, did you have to balance the carbonfiber driveshaft?

No, it didn't require any balancing on my end. In addition, I was lucky that my diff was balanced and didn't require the special bolts to make it balanced as noted in TIS if it wasn't. I've had it up to about 120 and haven't noticed any issues with the balance of either. I do have to say that Mfactory built a quality piece and makes the car drive even better.

[bmwm3s65]

Originally Posted by randrews15

No, it didn't require any balancing on my end. In addition, I was lucky that my diff was balanced and didn't require the special bolts to make it balanced as noted in TIS if it wasn't. I've had it up to about 120 and haven't noticed any issues with the balance of either. I do have to say that Mfactory built a quality piece and makes the car drive even better.

Also just wanted to confirm per your instructions, the only fastener components you replaced were the nuts that attach the guibo to the driveshaft, all the other bolts and nuts were reused except for those, correct?

[randrews15]

Originally Posted by glacket

Also just wanted to confirm per your instructions, the only fastener components you replaced were the nuts that attach the guibo to the driveshaft, all the other bolts and nuts were reused except for those, correct?

That's correct. I ordered the nuts through ECS once I had the part numbers off of Real OEM. TIS says to replace nuts and bolts, but I know there are others that reused everything and were fine. Just do your best in torquing it as close of spec as possible.

[bmwm3s65]

Originally Posted by randrews15

That's correct. I ordered the nuts through ECS once I had the part numbers off of Real OEM. TIS says to replace nuts and bolts, but I know there are others that reused everything and were fine. Just do your best in torquing it as close of spec as possible.

Thanks for the quick reply. i am getting ready to pull the trigger on the driveshaft and other "while your in there" parts like guibo, trans mounts, seals for headers to x pipe. i have test pipes, i am thinking of disconnecting the xpipe from the test pipes instead of from the headers. not sure if that is easier than disconnecting from the headers or not? any other tools/special tools you recommend besides e12 torx, 18mm grinded socket, ratchet wrenches you mentioned? . not trying to be a pest, i keep thinking of more questions as i research this further. Thanks for help.

[randrews15]

Originally Posted by glacket

Thanks for the quick reply. i am getting ready to pull the trigger on the driveshaft and other "while your in there" parts like guibo, trans mounts, seals for headers to x pipe. i have test pipes, i am thinking of disconnecting the xpipe from the test pipes instead of from the headers. not sure if that is easier than disconnecting from the headers or not? any other tools/special tools you recommend besides e12 torx, 18mm grinded socket, ratchet wrenches you mentioned? . not trying to be a pest, i keep thinking of more questions as i research this further. Thanks for help.

No worries about asking. I found having a Milwaukee motored 3/8 ratchet was a life saver. I don't think you need to disconnect the headers unless you're going to replace them. Not sure if you're running a stock x-pipe, but either way you should be able to just connect it from the test pipes and should have the clearance needed. I would also recommend having Universal joints. It's a pretty straight forward job and not too bad.

[bmwm3s65]

Originally Posted by randrews15

No worries about asking. I found having a Milwaukee motored 3/8 ratchet was a life saver. I don't think you need to disconnect the headers unless you're going to replace them. Not sure if you're running a stock x-pipe, but either way you should be able to just connect it from the test pipes and should have the clearance needed. I would also recommend having Universal joints. It's a pretty straight forward job and not too bad.

cool, I already have 3/8 motorized ratchet and socket u joints. i wasnt intending to disconnect the headers from the engine block i mean disconnecting the xpipe from the headers or disconnecting the xpipe from the test pipes. To me it makes more sense to leave the test pipes connected to the headers and disconnect the xpipe from test pipes. I am hoping to order it in a couple weeks. wish they had a sale on the 6mt like they do for the dct. that would sweeten the deal.