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Need advice on flywheel replacement
karmannghia60 - January 22nd, 2011 at 08:18 AM

My starter was spinning free few times before it connects so took it off to replace it but found that the fly wheel is worn. Must be the 6v starter in a 12v system
Dropped the engine down yesterday and it looks like I have a 200mm 6v flywheel (110 tooth) which I think not that easy to find. Can I just replace it with a 12v one? I will replace the start too. I know the thrust bearing has to be changed but I think that has been done already, see the picture of the pressure plate. I also recall reading before that some clearance has to be done in the bell hosuing. If the flywheel that is on the engine now already 200mm (but 6v) does it mean the clearance has been done and a 200mm 12v wheel will fit? I can't really see any clearnace done. I can only see some marks on the bell housing

http://i21.photobucket.com/albums/b277/karmann_ghia60/IMG-20110122-00185.jpg
http://i21.photobucket.com/albums/b277/karmann_ghia60/IMG-20110122-00186.jpg
Raf


matberry - January 22nd, 2011 at 08:36 AM

Mmmm, your right a 6V 200mm is rare as, but you can as a stop gap mod a 180 6V into a 200mm by machining out the clutch area in the flywheel, not my fav as you get a pretty wierd clutch surface, but it does work, then you still have a 6V starter. I've heard you can adapt a 12V solenoid to your 6V starter that will stop the problem occuring again but not done it myself. Otherwise to put on a 12V flywheel you need to mod the flywheel where it sits on the crank, a slight machine of the O-ring area, clearance the bell housing where your two yellow rings are, + another 80% or so of the circumference of the bell housing, fit an adapter bush to the gearbox for the 12V starter that you need to buy.


Craig Torrens - January 22nd, 2011 at 09:56 AM

If your motor has the later 6V 200mm flywheel ( TS Fastback motor), then a 12v 200mm will fit straight on the crank without any mods:tu:

If you do fit the 12V 200mm flywheel, you will then need to do what Matt said and clearance the gearbox etc.


Grey 57 - January 22nd, 2011 at 10:34 AM

its the clutch size thats different, not over all size of the flywheel. 200mm 6volter is the same diameter as a 6v flywheel with 180mm clutch. These were used in later 6v type 3's


karmannghia60 - January 22nd, 2011 at 11:50 AM

I am confused. Matt is saying it needs mods, Craig is saying it will fit without any. What I have on the engine now is:
- 6v 200mm flywheel
- 200mm clutch and pressure plate
- 6v starter
I am happy to ditch the 6v starter and get a 12v one. I do have a 12v 200mm flywheel in the shed. Can I bolt it on, do the clearance as Dean mentioned, use the same clutch and get a 12v starter? Would this work? Do I need to machine the 12v flywheel as Matt mentioned?
Thanks a lot
Raf


ian.mezz - January 22nd, 2011 at 01:21 PM

what car?
what size motor?
did you sit the 12 volt flywheel on your damaged one to see how much bigger it is.
can you put pic of starter motor.
you may need a 12v starter bush also.
I have put a 1971 1600 beetle motor into a 6volt box I just had to file in side box so that the fly wheel would fit.:blush:


matberry - January 22nd, 2011 at 11:29 PM

What I said I think makes sense, Craig is adding that there is a late 6V type three engine that the 12V flywheel will fit. Basically the late 6V flywheel went to O-ring seals instead of the paper gasket before the change to 12Volt, so if you had that particular model a 12V flywheel will fit the engine without any mods...to the flywheel, the trans case will still need clearancing. To clarify Grey67's coments, the OD of the flywheel is slightly larger on the 12Volt version regardless of clutch diameter. Early in my first post I mentioned that you could convert a 180mm in to a 200mm if you wanted a more basic repair although not my prefered option because the 6V starter will chew the ring gear again.


oldtub356 - January 24th, 2011 at 12:09 AM

Hi Rafik,
From an electrical perspective:
The usual cause of your problem is that the 6v Solenoid on the 6v Starter Motor, slams the 6v Bendix Gear on the Flywheel to destruction if you run 12v through the 6v Solenoid. The 6v Starter Motor, itself can handle 12v for short bursts, for many years operation. (If your car doesn't start quickly when turning over at these speeds, there is something else that needs fixing - if you persevere with putting 12v through the 6v Starter Motor for extended periods, the commutator on the armature overheats and sprays solder and wiring out of the commutator.)

- I like the 6v starter on a 12v system, if the Battery / Starter wiring is 6v, and the Battery 12v, the Starter is 6v, the Solenoid is 12v, the Bendix on the Flywheel is either 6v or 12v but matching the Starter gear (ie. both gears MUST be the same voltage/tooth pitch). It is necessary to fit a 12v gear on a 6v Starter Motor if using a 12v Flywheel with a 6v Starter.

This way, you get the 12v turning over the 6v Starter (and the Engine) at about x4 times the usual speed. BUT, if you also run 12v through a 6v Solenoid, the Starter Gear thumps the Bendix gear at x4 times the pressure/speed, while already spinning at high speed - usually wears a patch of gear off the Flywheel, about 100mm long on x2 opposite sides of the Flywheel (after about 6 months or so.)

The Guys above have explained the mechanical fits.


karmannghia60 - January 25th, 2011 at 08:42 AM

Thanks All, got it
Decided to convert to 12v flywheel and starter to avoid the same problem in future. Fitted the new bush and started grinding this morning with a small grinding wheel on a drill. Still lots of grinding to do
http://i21.photobucket.com/albums/b277/karmann_ghia60/IMG-20110125-00194.jpg

The 6v starter solenoid had one terminal going to it, the 12v has 3. I've been told to use the taller terminal on the 12v starter
http://i21.photobucket.com/albums/b277/karmann_ghia60/DSCN0543.jpg


karmannghia60 - January 27th, 2011 at 01:49 PM

Changed everything to 12v yesterday. I used an old 12v starter that I had. It hardly can turn the engine over about 1cm at a time. Not sure if it is a bad starter or the battery doesn't have enough juice in it. Been sitting for a month. I put the battery on the charger this morning and will try again tonight. So I might be looking for a 12v starter soon


dogo - January 27th, 2011 at 02:27 PM

Will the engine turn over by hand? the flywheel may be touching the bellhousing!


karmannghia60 - January 27th, 2011 at 02:39 PM

Nah, checked it already. Turns over fine


clinker42 - January 27th, 2011 at 03:07 PM

Indo the two small inner screws on the bearing cap, remove the circlip and spacer washers. Then undo the two outer and remove the brush cover.

I bet you have no brushes left

How do I know, because only 1 week ago my daughters starter would do the same thing. Took some brushes form a Holden bosch starter and stuck em in and it now works a treat.


karmannghia60 - January 28th, 2011 at 08:25 AM

Thanks for the tip, did what you suggested and the brushes are OK but they were quite dirty. Cleaned everything up and now it is working :)


darrens66 - January 28th, 2011 at 09:18 AM

Great info and great photos if I want to convert my flywheel and starter motor to 12 volt. Was the motor and bell housing out of a Type 3?


karmannghia60 - January 28th, 2011 at 09:54 AM

Hi Darren, no all T1
I can post more pics if it is of help to you or anyone else