Replacing the E39 M5 Clutch and Flywheel with Original Equipment - The Unofficial BMW M5 Messageboard (m5board.com)

OldRanger · 30th April 2007, 20:51

Objectives:

1. Eliminate clutch slip
2. Reduce or eliminate vibrations and resonance in the vehicle body

At 7yrs and approximately 76,000 miles, I decided to change my original clutch after I began to notice slipping during aggressive shifting. I decided to change the flywheel while I was at it because I believed that increased vibration and resonance in my car was related to failing components in the Dual Mass Flywheel. Based on my review of DMF design in LuK technical literature – I do not believe these are life-time components, regardless of the condition of the friction surface.

I wanted to stay with original equipment (LuK) because it is best suited for what I need 95% of the time that I’m driving my car, and I didn’t want to accept the negative aspects of going to higher performance clutches. I also didn’t want to pay the premium for the lightened DMF that Dinan sells. Based on what I’ve read, I would not recommend using a standard (single mass) flywheel on the M5 unless you’re primary use requires ultra-high performance and you are willing to accept the drawbacks. The engine and drivetrain is a system that was designed with the functionality of a DMF in the equation.
I decided to do the job myself. It is a difficult DIY’er, but it can be done with the proper tools in one day. I am "mechanically inclined", but I have no qualifications other than I am persistent, I pay attention to details and I follow instructions. I had access to a friend’s shop and I had all the special tools listed below as well as a basic set of air and hand tools. Just as important, a fellow M5Board member (emccallum) was available on the phone to help as I needed it. I contemplated trying this job on jack stands, and I believe this job can be done that way. That said, based on my experience you’d have to be insane to do this job without a lift and a transmission jack.

Results: The new clutch shifts great, the vibrations are significantly reduced, and the resonance that the LuK engineers call "body boom" is gone. I presume that when I can get back to "spirited" driving, that the clutch engagement will be much firmer. I didn’t expect the clutch pedal feel to improve so much, but it is quite effortless now. I suspect this is primarily related to a worn out release bearing.

Phase 1: Get the parts, supplies and tools you need

LuK Parts same as OE (available at Autozone with warranty)
Clutch Kit 03-042 $312.99
Flywheel DMF021 $534.99
(Clutch kit includes pilot bearing and release bearing)

BMW Parts:
6 Bolts for clutch 07-11-9-901-023 $5.16
Retainer Spring 21-51-1-223-234 $5.67
Release Lever* 21-51-1-223-302 $23.53
2 Transmission Mounts** 22-31-6-771-221 $28.70
2 L Trans. Oil*** 83-22-0-406-941 $49.32

Parts Total Price (as of 4/2007) $960.36

* At 7yrs and 75k miles (and lots of gear changes), my release lever was noticeably worn at the contact points with the slave cylinder "push rod" and the ball pin. For $24 bucks replacing this is wise.
** My old transmission mounts were visibly OK, but when compared to new ones – they were about 5mm smaller than fresh ones.
***Go ahead and do the transmission oil now. It makes sense, and only adds about 5% to the parts cost.

Supplies:
Grease for clutch disc and transmission splines
PB Blaster penetrating oil (for exhaust bolts at header)
White Out for marking driveshaft and center bearing

Special Tools: You will need the BMW TIS instructions and associated torque specs for: Removing and installing complete exhaust system, Removing and installing transmission, Removing and installing or replacing clutch, Removing and installing or replacing clutch release bearing/lever, Removing and installing/replacing flywheel.

Torx socket E12 (3/8 in drive) for fasteners on clutch housing to engine
3 foot socket extension (3/8 in drive) to reach the Torx fasteners
#6 Hex driver for Clutch to flywheel bolts
Clutch Alignment tool (LuK CT-1012, or similar)
T-60 Torx driver for flywheel – (BMW tool 114180 or some other torx driver that reaches into the flywheel deep enough; approx 1.5 inches. If you don’t have the special tool, check your’s prior to beginning work. The BMW tool also has a shaft that is the right size hex driver to remove the locking piece on the new clutch)
Torque wrench up to 105Nm
Pilot bearing puller
Lift (like I said, you would have to be insane to do this on jack stands)
Transmission Jack
Floor Jack/Support for Engine (and Exhaust during different steps)
Straps with cam-lock buckles (they help during the exhaust removal if you’re a one-man show)

Phase 2: Study the technical literature on BMW TIS
If you’ve never done a BMW clutch before, I suggest you read through the BMW TIS literature a few times prior to the day you plan to do this work so you’ve got the basics in mind. This is kind of like studying for a test – the more familiar you are with the "material" prior to beginning, the more likely you are to succeed. My purpose with these notes is to supplement the TIS instructions – not replace them. I wrote these with the benefit of hindsight. Do this only with the TIS instructions handy (maybe even in a binder) – and force yourself to follow them step by step during removal and installation.

Phase 3: Take it all apart per TIS
I didn’t take any pictures during this job because the pictures and photographs in the TIS are more than adequate.

Safety first – nothing in this job is worth getting hurt. Get this car up on the lift properly and take your time. (Patience, glasses, gloves, etc.)

A. Removing complete exhaust system

Hit the bolts at the exhaust manifold with some PB Blaster right as soon as you get the plastic cover off the bottom. Let them soak while you take off the sensor connections.
When you’re taking apart the O2 and temp sensor connections, remember which sensor goes in which slot in the cable holders and the orientation of the wires.
There is no need to remove the rear bumper/splash guard. In hindsight, I’m sure it makes the exhaust removal and installation easier, but is not mandatory.
If you are a one-man-show: Prior to un-bolting the exhaust system, strap it up to the rear suspension sub-frame as well as the hanger under the transmission. Then you can remove the fasteners while the car is high on the lift, then move the car closer to the ground to lower the exhaust to the floor with the cam-buckle straps.
After you’ve removed the nuts on the connections between the manifold and pipes, tap them with a mallet to break loose the rust.
To wrestle this system off the car: If you don’t remove the rear splash guard, you will want to lower rear of the exhaust system (mufflers) down below it so you can push the complete exhaust system down and to the rear to get it off the bolts near the manifold-to-pipe connections. (This is probably why the TIS recommends to remove the bumper)

B. Removing transmission (includes removing the heat shields and driveshaft)

I recommend draining the transmission oil prior to removal. This prevents a potential mess when you twist and turn the transmission during removal – and at only $50 to replace the oil – it makes sense to do so now.
When you remove the heat shields, place them on top of the exhaust in the same manner they are installed so you can remember how it all goes together.
When you remove the driveshaft – mark the position of the center bearing on the bottom of the car with white-out or something like it so you can reinstall it in the same position. Do same with flex disk at the connection with the driveshaft.
I didn’t have the "special tool" that keeps the engine in the proper position when the transmission mounts are removed, but I used a floor jack with a 2x4 and that worked OK. It also allowed me to raise/lower the engine when I was installing the transmission.
The driveshaft can remain attached to the rear differential. It can be easily moved out of the way and strapped up for the job per TIS.
I recommend using a transmission jack that allows you to rotate the transmission during removal. I tried every angle and height possible, but couldn’t get the bulges in the clutch housing for the starter to clear the exhaust manifold without rotating the transmission.

C. Removing clutch

When you pull off the clutch, the clutch plate will fall off the flywheel – so be ready.

D. Removing clutch release bearing/lever

No additional recommendations from TIS

E. Removing flywheel

No additional recommendations from TIS
I did not have the special tool to block the flywheel – I used impact wrench for removal.

Phase 4: Put it all back together per TIS
When you move to the "Installation Phase" be disciplined and work back through the TIS steps in reverse, following directions closely to avoid rework.

A. Replacing flywheel

If you don’t have the tool to block the flywheel, you will have to get really creative, or have a second set of hand to secure the flywheel while you torque to bolts. This is the only step I had help on. (You have to crank on these bolts - 105Nm)

B. Installing clutch release bearing/lever

I’m not sure what an appropriate "high-quality" grease is, but the LuK technical literature says do NOT use a grease with suspended solids in it. They also recommend that once you put grease on the splines of the transmission input shaft, slide the driven plate’s hub onto the shaft and remove any excess grease.

C. Installing new clutch

The LuK clutch tool (CT-1012) was not in stock anywhere, and I was not about to pay $65 for the BMW tools – so a friend graciously let me borrow a plastic alignment tool marked "BMW25". It was apparently designed for clutches that don’t have the locking piece holding the self-adjusting mechanism in place prior to installation, and didn’t work with the parts I had. It fit the clutch plate splines and pilot bearing perfectly, but was too long and didn’t fit in behind the locking piece.
So – with no alignment tool, and luck on my side…I used screw drivers wedged in through vents in the clutch to align the outside edges of the clutch disc with outside edges of the spring plate, crossed my fingers and removed the locking piece. This worked just fine and the alignment tool slid right into the pilot bearing after I removed the locking piece. Like I said – I was lucky.

D. Installing transmission

Remember the angles and rotations used to remove the installation and try to reproduce them in reverse. I started with my transmission rotated counter-clockwise about 90 degrees to get the bulges in the bell housing (for the starter) past the exhaust manifold.
Keep the clutch slave cylinder up and out of the way for most of the time as you get the bell housing to within a couple of inches of the engine. Then pull it down and protect it during the rest of the wrestling match.
Remember to pull the wires for the reversing light and gear detection switch over the transmission before you get too far along.
Be prepared to lower/raise the engine a centimeter or two while you are lining up the transmission.
The transmission jack I used had adjustable angles, this came in quite handy when moving the transmission back in to position.
Be patient, and plan on this taking some time.
When you’re reinstalling the driveshaft, follow TIS instructions and don’t over-torque the nuts on the flex-disc bolts. If you do, the flex disc will deform slightly and those nuts don’t come loose easily to reset the torque. Tighten from the nuts only, and when the bolt starts to turn – stop.

E. Installing complete exhaust system

For the exhaust system, working backwards through the TIS steps doesn’t work completely if you didn’t remove the rear splash guard (bumper).
If you left the splash guard on (like I did), keep the mufflers just below that until you’ve line up the manifold-to-pipe connection and got the bolts through those clamps.
Put the nuts on those bolts at the manifold-to-pipe connection, but don’t torque them down completely yet.
Move back to the muffler hangers and get the bolts lined up back there now. Tighten all of the fasteners down.

F. Refill the Transmission oil.

Unless you’ve got some cool equipment for filling transmissions up with oil – you’ll have to get creative.
I had 2 liters of oil for the necessary 1.75 liters of capacity.
I had a funnel and a piece of coolant hose that had an outside diameter that allowed it to fit snuggly in the fill hole of the transmission.
I routed that hose down from the fill hole, under the body, then up through the wheel well. I slowly poured the 2L down the funnel/hose, then plugged up open end of the hose with my finger, lowered it down below the fill hole of the transmission and pulled it out of the transmission. A small amount of excess drained out of the transmission; I dumped the excess in the hose. Job done.

G. Wrap Up

Double check all sensor connections and the routing of the wires around the transmission and through each of the clamps.
Install the plastic underbody
Job done – congrats!

Breaking in a new clutch (per TIS)
Aggressive driving maneuvers will destroy a new clutch. Break in the friction linings of the clutch by applying light to medium loads under "normal" driving conditions. This preconditioning creates a carbon layer between lining and metal friction surface, important for creating the necessary coefficient of friction.
"Normal" driving conditions involve drive-off speeds of up to 2500 rpm on normal surfaces up to a medium gradient (12% or less).
When a vehicle is moved "normally", approx. 800-1000 gearshifts should result in an optimally broken-in lining. When breaking the clutch in, drive off at max. 2000 rpm; upshift 1->2, 2->3, 3->4; upshift at 3500-4000 rpm, downshift 4->3, 3->2, 2->1, downshift at 2000 rpm.

Other comments:
Based on the condition of the transmission mounts (compressed) I suspect changing the engine mounts would help to further reduce vibrations.
Consider cutting the exhaust in half while your at it. I suspect that anyone who does this more than once would want to separate the exhaust system into two pieces prior to removing it. In spite of adding a little bit of time cutting, then clamping during install – I suspect this would shave at least a half hour off the job. Perhaps cutting just behind the post-cat O2 sensors would be a good idea. (This is where the dealers cut the system if/when you need your cats to be replaced)

CSBM5 · 3rd June 2007, 20:41

Andy,

This is a great post with wonderful, detailed information. On behalf of the board, thank you very much for this contribution.

How are things going with the new clutch now? Any issues?

Regards,
Chuck

OldRanger · 6th June 2007, 05:15

Thanks - I've gained a lot of knowledge (and opinion

) from this board. Both are important. I was glad to put it together. Sorry for the lack of pictures - I know that grabs the attention, but there was really nothing noteworthy to photograph. The pictures in the TIS are more than enough.

Hope this helps others gain the confidence to give this a shot.

New clutch is great - quiet, no vibrations, feels like new.

Laidback · 9th June 2007, 05:10

Thanks for the write...just in time as i am breaking in the car today (new clutch and flywheel)

BubzM5 · 4th November 2007, 05:04

Andy,

Thanks for taking the time and effort to do the thorough write up. I am about to get my clutch replaced and this information is perfect.

I didn't see the throw out bearing or the pilot bearing on the list of parts to replace. Did you get these parts replaced?

Regards,

-B

OldRanger · 4th November 2007, 14:11

Your welcome! I'm glad it's useful for someone.

The pilot bearing and the release bearing (throwout) both came with the clutch kit from Luk.

WhiteHorse · 22nd December 2007, 19:28

Hi. I've used your write up and am installing the transmission. I'm struggling to get the transmission the last 1/4 inch onto the back of the engine. Did you have trouble in this area? I've been slightly raising and lowering, side to side and I pulled it back and can see that the trans input shaft has gotten into the bearing about 1/3 of the way. Any tips or ideas? Thanks. This was an awesome write up and it has gone very smoothly to this point.

OldRanger · 28th December 2007, 15:35

Took me a while to notice your question, so I presume you've made it past this point, but for the benefit of others:

I experienced this difficulty as well, and as best I can recall this is all about ensuring the transmission is properly aligned. I just worked through it ensuring I had some method to the madness. I also happened to have a very nice, fully adjustable transmission jack that I made minor adustments on until I finally got the thing properly aligned.

I hope everything turned out for you!

WhiteHorse · 4th January 2008, 16:48

I did get it licked. I pulled it back and double checked everything once more and then tried again. I was able to get it back to the, roughly, 1/4 " of the being together and, again I struggled to get it past that point. I inserted the bolts all around the housing and, about 1/4 turn at a time, slowly pulled it together.

As you reported, the car is much better with the new flywheel and clutch.

Thanks again for the great post. It got me over the top and was a great help.

Ted · 21st August 2008, 14:20

Wow, great write up! I was about to change my clutch out because it was slipping when I first bought the car, but amazingly the car has healed itself and not only has it not slipped in a year, but the shifts became smoother as well. I think the transmission has magical properties