Flywheel questions

Stevehose

Stevehose

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I am going to replace pilot & throw-out bearings and clutch after I fix my tranny shift rod seal leak for good (hopefully).

1. Is there anything special about the flywheel that a machine shop should know about for resurfacing? Or is it a basic design that they can do?

2. Do I need the alignment "dowel pins" for reassembly (3 x $5 each).

3. Are new bolts available? Looks like the original ones were superceded with different ones - does this matter?

4. Good way to fabricate a flywheel lock tool?

5. Any other flywheel pitfalls to be wary of or advice when doing this project?

Thanks.
 
Last edited:
Steve
1. Any good machinist will work.
2. I only remember 1 and probably needed if csi, for correct location of trigger for ecu.
3. Use new #, but I used old bolts. Use proper torque procedure
4. Borrowed one
5. Keep it clean!!!! Wear new gloves when handling clutch, always. Change often as necessary.

Have fun, a great project.

reno
 
Make sure the shop steps the flywheel-
Forget the dowel pins
Always get new bolts
Always use thread sealer on the flywheel bolts
The spec is for 1 gram of grease for the pilot bearing
A spare bolt is fine to hold the flywheel
Be ever so careful with that seal- they are so delicate.
Buy a spare- for 2.75 it's a good idea
http://www.autohausaz.com/search/product.aspx?sid=vjrs5p45yscellywqxpc2t45&partnumber=23121282394
Get the input and output seals
Always-always take one last look in there to make sure the TO bearing is set before bolting the damn thing back together

Get a new knuckle
Get new brackets 25111202842

Have fun!
 
sfdon said:
Make sure the shop steps the flywheel-
Click to expand...

What does this mean?

sfdon said:
Be ever so careful with that seal- they are so delicate. Buy a spare- for 2.75 it's a good idea
Click to expand...

I have 3! I messed up the last one and it leaks, the other seals are ok after i replaced them last time.

I don't want to go back in here which is why I am doing the clutch work even though it doesn't really need it.

I did the shift tower bushings and linkage bushings etc last time and it shifts like a dream - smooth, crisp, and tight.
 
The contact area of the flywheel should be raised[or higher ] than the rest of the flywheel.
Any good shop will know what to do.
They will pull the pins and machine the whole surface whilst leaving the contact area 1mm higher. 35-50 bucks
 
Got it thanks. However "good shop" and "New Orleans" are mutually exclusive right now!

sfdon said:
The contact area of the flywheel should be raised[or higher ] than the rest of the flywheel.
Any good shop will know what to do.
They will pull the pins and machine the whole surface whilst leaving the contact area 1mm higher. 35-50 bucks
Click to expand...
 
I just moved back from Baton Rouge a couple years ago- there were plenty of good shops there. Slidell has a good driveshaft place.

Wedge Keyes will have good info for you.

Run like hell from the whack job on college.. he screwed me on my Maserati.
 
Stevehose said:
I am going to replace pilot & throw-out bearings and clutch after I fix my tranny shift rod seal leak for good (hopefully).

1. Is there anything special about the flywheel that a machine shop should know about for resurfacing? Or is it a basic design that they can do?

Give the shop a printout of the below repair manual page (showing min thickness) and write down the acceptable runout spec from the Specifications section of that website. Have the shop first agree that they can perform the job to these specs or to not proceed of they can't. Some flywheels are beyond repair; no joy in doing the tranny pull twice.

http://www.e9-driven.com/Public/Library/BMW-E9-Manual/pages/en/11220000.html#refertoc


2. Do I need the alignment "dowel pins" for reassembly (3 x $5 each).

In doing mine, these helped hold the pressure plate vertically while I torqued down the bolts. The pressure plate will resist being pulled against the flywheel by the bolts. You'll have to push against the plate assembly to get the bolts started; no need to have to push and lift (vertically) because of missing dowel pins. If you can't remove them, have the machine shop do it. Dowels also clock the assembly relative to the flywheel, which aids installation of attachment bolts.



3. Are new bolts available? Looks like the original ones were superceded with different ones - does this matter?

Don't reuse the old ones; new ones are cheap and come (correct me if wrong) pre-coated with yellow locking paste. Otherwise, one must use red locktite on threads per service manual.


4. Good way to fabricate a flywheel lock tool?

I recommend just buying the proper one from Bavarian Auto, E-Bay, etc. You will also need a clutch assembly centering tool, which is a dummy trans input shaft. Also avail. from Bav Auto, etc.


5. Any other flywheel pitfalls to be wary of or advice when doing this project?

Use graphite grease or Molycoat on all surfaces identified by repair manual (linked above). Especially the trans input shaft, shaft tip, and shaft splines on which the throw out bearing rides.
Click to expand...
 
Got the flywheel back from the shop, stepped per Don's advice. Before and after:

IMG-20110619-00366.jpg

IMG-20110620-00372.jpg


It looks amazing and is spec per your suggestion. Waiting on clutch kit, pilot bearing, alignment tool, bolts, guibo etc. I scored a sweet Snap On 200lb 1/2" torque wrench on craigslist today for $40. I love the internet. Thanks for everyone's advice, this is a first time project for me.




hans3 said:
Stevehose said:
I am going to replace pilot & throw-out bearings and clutch after I fix my tranny shift rod seal leak for good (hopefully).

1. Is there anything special about the flywheel that a machine shop should know about for resurfacing? Or is it a basic design that they can do?

Give the shop a printout of the below repair manual page (showing min thickness) and write down the acceptable runout spec from the Specifications section of that website. Have the shop first agree that they can perform the job to these specs or to not proceed of they can't. Some flywheels are beyond repair; no joy in doing the tranny pull twice.

http://www.e9-driven.com/Public/Library/BMW-E9-Manual/pages/en/11220000.html#refertoc


2. Do I need the alignment "dowel pins" for reassembly (3 x $5 each).

In doing mine, these helped hold the pressure plate vertically while I torqued down the bolts. The pressure plate will resist being pulled against the flywheel by the bolts. You'll have to push against the plate assembly to get the bolts started; no need to have to push and lift (vertically) because of missing dowel pins. If you can't remove them, have the machine shop do it. Dowels also clock the assembly relative to the flywheel, which aids installation of attachment bolts.



3. Are new bolts available? Looks like the original ones were superceded with different ones - does this matter?

Don't reuse the old ones; new ones are cheap and come (correct me if wrong) pre-coated with yellow locking paste. Otherwise, one must use red locktite on threads per service manual.


4. Good way to fabricate a flywheel lock tool?

I recommend just buying the proper one from Bavarian Auto, E-Bay, etc. You will also need a clutch assembly centering tool, which is a dummy trans input shaft. Also avail. from Bav Auto, etc.


5. Any other flywheel pitfalls to be wary of or advice when doing this project?

Use graphite grease or Molycoat on all surfaces identified by repair manual (linked above). Especially the trans input shaft, shaft tip, and shaft splines on which the throw out bearing rides.
Click to expand...
Click to expand...
 
I just read where i said Forget the dowel pins........
I meant forget about buying new dowel pins..
hans3 is very correct- you need them to stick the clutch while you put in the bolts.
New bolts always.
Your flywheel looks a 1000% better!
 
Maintenence complete

Thanks everyone for the help - new pilot bearing, resurfaced flywheel, clutch, pressure plate, throwout bearing and flex disc successfully installed. I replaced the flex disc even though it looked ok, glad I did - it was split half way! First time doing this kind of work - frustration followed by rewarding feeling.

Also replaced the shifter seal on the tranny and cured that leak - no drips on the garage floor now!

Previously replaced center bearing and rebuilt the shift linkage.

Shifts like a new car now - crisp with no linkage play.

Next up, a/c upgrade and diff support.
 
I know this thread is old but it was incredible helpful.

My flywheel looked pretty much like @Stevehose one.

just been resurfaced. Machinist also suggested only stepping down the mounting area by 0.5 mm.

before and after pictures.

0E6057EA-1AB8-4093-B0C8-352755C70682.jpeg
BB375835-1535-4DA2-B7CC-369092773C7C.jpeg
 
That looks like it was done on a lathe instead of the usual milling machine I hope that the area that contacts the disc was machine very very smooth without any lathe marks The reason for that is that sometimes the lathe marks act like a screw and will in a manner act like a thread and will pull the contact surface one way or another depending on the lathe cuts. Only will last for a bit until the grooves are worn away Have experienced this a couple of times with frt brake rotors and too quick a machining job It caused the pads to thread themselves away from the rotor, then would bag back into place whenever you hit the brakes. Had to drive it and brake hard a bunch of times over 2 days to get rid of it but eventually did go away.

Look at the 2 pictures and you can see the difference in the machining job

Thanks, Rick
 
stphers said:
That looks like it was done on a lathe instead of the usual milling machine

Look at the 2 pictures and you can see the difference in the machining job

Thanks, Rick
Click to expand...

My mechanic seems happy with it...I have to go with his advice but I’ll ask the question.

thanks for the info.
 
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