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Discussion Starter #1
Hello.
I have converted an 82 VW Rabbit Convertible with an AC50 at 96 volts. The power is awesome and my range is pretty nice with a Lithium pack. The trouble I have is a pretty good vibration that starts at about 20MPH and drowns out the radio at 55MPH. I was first thinking that I had a thumping CV boot or something, but I ran up on jack stands and have a strong suspicion around the flywheel. I have several issues going on. The ICE was half out of the car when I bought it, so I don't have any history. The transmission was in the front seat (easy to work on) with a hole in the bellhousing. I repaired the transmission, but it is currently stuck in fourth gear. Amazingly, the drivability in fourth gear all the time is not so bad. I didn't have the clutch tool to line up the clutch plate and the pressure plate between the flywheel, so I did the best I could with a caliper tool. So I feel that I did okay getting it all together and am driving it everyday to work (45 miles round trip at 55MPH).

Here is the thing. My hub bottoms out on the motor shaft to an expanded ring inside the hub. The shaft and hub are slipped together with a 1/4" square key. That's it. The hub is free to move along the motor shaft and the splinned shaft on the transmission. The only thing keeping the flywheel from ripping through the bellhousing is the right-hand rule and the clutch push rod from the transmission. I don't recall having an exceptional time getting the hub to fit and line up on the motor shaft. I actually put the clutch assembly and hub on the motor shaft all at once (several times while I worked out the hub being too long.)

Has anyone else done it this way or have I just been really lucky so far? Do I risk the flywheel floating into my bellhousing during regen braking? What is it supposed to be? I would like to fix it when I swap out the transmission so any ideas would be appreciated.

I have a video of my flywheel through the starter hole (before I got stuck in 4th.)
https://dl.dropbox.com/u/92151597/20121222_091508.mp4

Thanks ahead for the help.

http://www.evalbum.com/4184
 

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First of all I would 'fix ' the hub to the ac-50 shaft and remove the flywheel and have the whole clutch assembly dynamically balanced. The repair shop could then tell you if everything is in round and straight (run out). The throw out bearing is not intended to hold everything on the mainshaft axis. If I can hear and see the vibration on your video ,then it is not a good sign.
 

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I'd take out the motor and check all your connections and by all means have that flywheel pressure plate balanced and notched so you can only put it on one way so it remains balanced. The disk does not need to be installed during balancing but you can if you want. Replace the throwout bearing while your in there. Its cheap insurance. Be sure nothing is bent or rubbing. The video sounds pretty lousy and you can see movement indicating an out of balance setup.

Pete :)
 

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"The hub is free to move along the motor shaft"

If you haven't already ruined the motor shaft I'll be amazed :(

The hub should be an interference fit (shrunk on). The motor shaft is probably fretted and worn by now. $$$$$$$$


Derek
 

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Any "set-screw" type hub should require some heat before it will slide up on the shaft of the motor, and require a puller to remove. (A light interference fit).

If the hub slides at room temperature on the motor shaft, do not use it as it is too loose.

A clutch pilot tool is only for easier assembly and does not really set or keep alignment, the transmission splines do that. If you were close enough for it to slide together, good deal. Just because you did not use a tool to install did not necessarily mean it was out of alignment.

If you do not use a flywheel, you can get by with a lot as it will not show up. Any mistakes are near to the axis of rotation and will not be readily apparent. But, a flywheel installation requires precision. A slip-fit flange is no good.

Now all you need is your motor shaft turned to 1-1/16" o.d. and a new hub made.....

Sorry...Miz
 

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Discussion Starter #7
Looks like I'll be pulling everything apart this weekend. I only have about 500 miles, so maybe it isn't bad. I'll post some pictures.
Thanks everyone.
 

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I had a heck of a time to get clip to load but what I saw and heard was not good. If you watch close at the left side of the starter housing some specks of what could be metal appears to be flung up when the motor is revved. I agree with everyone else’s advice and add that you do not run the setup anymore even for a demo. Also when you pull it apart to do repairs have the ring gear removed as it is just added weight.
 

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Discussion Starter #9
I get it. Don't drive it any more until I fix it. The real message here is to spend money right and watch out for the guy who will save you a few bucks today that will cost you double later.
The flywheel is the rabbit clutch assembly and has an asymmetrical bolt pattern that should be related to balance and the timing of the original ICE. The belhouse is a tight space and yes there is some visible travel, but the vibration seems minor as it doesn't go beyond the flywheel and shake the motor and trans box. My true thoughts are that the face is not exactly perpendicular.
To my question, if I take everything apart and find no damage (doom and gloom guys everywhere) which type of hub works best with the least possible failure? Obviously, PFM and the right hand rule is not enough to be dependable.
 

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I get it. Don't drive it any more until I fix it. The real message here is to spend money right and watch out for the guy who will save you a few bucks today that will cost you double later.
The flywheel is the rabbit clutch assembly and has an asymmetrical bolt pattern that should be related to balance and the timing of the original ICE. The belhouse is a tight space and yes there is some visible travel, but the vibration seems minor as it doesn't go beyond the flywheel and shake the motor and trans box. My true thoughts are that the face is not exactly perpendicular.
To my question, if I take everything apart and find no damage (doom and gloom guys everywhere) which type of hub works best with the least possible failure? Obviously, PFM and the right hand rule is not enough to be dependable.
I have had no problems with taper lock and clutchless. installation took a few attempts but ended up with less than .001 runout.
 

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Ok, in an ideal world here's what to do.

Lightly machine the motor shaft(rotor out job) to restore surface finish.

Accurately machine up a keyed hub from steel that is an interference fit on your motor shaft, which will be machined to be an exact replica
of the ICE crankshaft (it'll probably have a spigot/register to ensure the concentricity of the flywheel). Use quality bolts.

Have the hub and flywheel dynamically balanced on a mandrel/dummy shaft.

Then add the pressure plate and dynamically balance whole assembly again but only adding/removing mass
from the pressure plate to achieve tolerance (ISO grade 2.5 in each case).


It would be worth taking the opportunity to lighten the flywheel as much as is reasonable at this opportunity too (before balancing).
I never much liked the idea of a large diameter heavy flywheel hanging on a small diameter shaft.


Derek
 

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It looks like The Electric Car Company specializes in a flanged tapered bushing (also called a QD type) type hubs. Is this what you have? If so, are the bolts clamping the tapered bushing (the one with the slot or slots cut in it) to the hub torqued properly? If they are, and the bushing is the right size for your motor shaft, the bushing should firmly grip the shaft. There should be no "sliding" on the motor shaft.
 

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Discussion Starter #13
It looks like The Electric Car Company specializes in a flanged tapered bushing (also called a QD type) type hubs. Is this what you have? If so, are the bolts clamping the tapered bushing (the one with the slot or slots cut in it) to the hub torqued properly? If they are, and the bushing is the right size for your motor shaft, the bushing should firmly grip the shaft. There should be no "sliding" on the motor shaft.
This is where my hub came from, but it is a single cylinder with a 1/4" key. Slides on and off very smooth. I will expect the clutch assembly to stick to the transmission spline when I pull them apart with the hub still bolted to the back of the pressure plate. I suppose they made one special for me that is different. Obviously, this is my first conversion. Seems I'm just lucky this way.
 

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OK, does your hub have set (grub) screws? Most often the screws go over the top of the keyway but, they could be anywhere. And, if it does, do you not tighten them or do they work loose such that the hub easily slides on and off?

As others have mentioned, this hub could be designed to have an interference (pressed-on)fit. Talk to the supplier.

A picture and an explanation (maybe from the supplier) might help us figure out this problem.
 

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Discussion Starter #15
This is really getting off my original point of trying to identify any advantage of one method of fixing the hub to the shaft over another. Clearly my hub that does not attach to the shaft is poor and hopefully, I won't find too much trouble from my small amount of use. I will work with my hub provider to rectify with a new one that resolves my slight wobble.
Here are some pictures I took of the first hub that was nearly identical to the second hub that is currently in use. Sorry they aren't the best.

This hub was set up by a real bonehead with the pressure plate bolt holes threaded on the back side of the hub (where the motor is). There are no set screws. The expansion ring bottoms out on the end of the shaft. The second hub basically moved the expansion ring to the correct end of the hub.
 

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Discussion Starter #17
Looks like some damage to the motor face. Again, this is after only 500 miles. I didn't notice the hub contact with the motor face when I put everything together, but I suppose the adapter was in the way.
 

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The "rust" you see is typical fret wear corrosion where parts work against each other without good lubrication. I see on the ECC web site this hub offered as their preferred design(I should have scrolled down further). Unless I'm missing something, it seems like a goofy design to me.

Maybe this design is in response to DIYers complaints about the fitting(filing, scraping, and indexing)sometimes required with tapered bushing couplers. Sometimes the cure is worse than the illness.
 
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