Alternator Rotor Chip

[first timer]

several years back someone had suggested packing the rotor end with grease then running the bolt in. The theory being the grease being compressed acted as a hydraulic jack and the rotor would come off rather easy. I haven't had a chance to try it but I do remember a few guys having good luck. Worst case you could go back to using a slide hammer.

[tom203]

With a slide hammer you are just exerting force directly onto the rotor, whereas with the other method you are in effect hammering direct onto the crank (with small socket inserted). The slide hammer is pulling away from the crank and the other method is hammering directly onto and pushing the crank into the engine. To remove my rotor (and as I said it had been Loctited to the taper) it took only two slides of the hammer, whereas if you look at the end of Scott's tool there were many more impacts than that.

What ever works for you is fine.
The socket on bolt method puts tension on rotor while putting compression on bolt to crankshaft end- usually no need to "hammer"- tighten bolt, tap rotor to jar it, more tightening. more tapping and the rotor will slide down the taper and free itself. Of course, you have to get a proper socket and put its drive end against crank so not to damage crankface. If it's really stuck/rusted, you might have to hammer on bolt, but this is different from the force that a slide hammer is exerting.

[Matchless]

I recently had to remove a rotor from a BMW R100 and their method seems to work quite well and may work on our GS's as well, although I have not tried it yet.
Although they have a special bolt, I made one up as per the picture. I used a piece off an old screwdriver shaft that just clears the threads inside the crank end which is high tensile. This is important as a softer metal rod may bend or deform and get stuck.
The bolt used must also be high tensile so that the end pushing on the rod end does not deform.
The bolt is then screwed down into the rotor and onto the end of this metal rod which puts force on the inside of the crank end. Thus no pressure on the tip of the crank.
When its nice and tight a sharp tap with a hammer on the bolt head and the rotor pops off easily.

[tkent02]

Thanks all. I picked up a 12mmx1.25 tap to clean up that hole after getting a gauge to verify the bolt's thread pitch. I also picked up a new bolt albeit the same size (I didn't see Mike's post til afterwards) as the old one since it looks like the threads are messed up on a small part of it.

If I return that bolt and get a tad longer (the one I have is 45mm long and Ace has a 50mm), will it hurt anything inside that crank to retap it so I can thread the longer one in?

Is the hole deep enough for the 50mm bolt? You do NOT want the bolt to bottom out when it is tightened.
Is the bolt from Ace the proper grade?
If not call AAA Metric in Denver, they should have exactly what you need.

[cowboyup3371]

Tom, after talking with Josh last night I'll stick with the 45mm bolt since he was saying that crankshaft might be too hard to rethread. Also, the bolt I picked up from Ace has the 8.8 marking on the head which based on everything I've read is pretty strong and applicable to this usage (old one is marked with a 7).

Am I wrong? If so, please let me know and I'll get down there to replace it.

[Suzuki_Don]

What ever works for you is fine.
The socket on bolt method puts tension on rotor while putting compression on bolt to crankshaft end- usually no need to "hammer"- tighten bolt, tap rotor to jar it, more tightening. more tapping and the rotor will slide down the taper and free itself. Of course, you have to get a proper socket and put its drive end against crank so not to damage crankface. If it's really stuck/rusted, you might have to hammer on bolt, but this is different from the force that a slide hammer is exerting.

Tom, we will agree to disagree. I will bow out gracefully.

[Nessism]

Tom, after talking with Josh last night I'll stick with the 45mm bolt since he was saying that crankshaft might be too hard to rethread. Also, the bolt I picked up from Ace has the 8.8 marking on the head which based on everything I've read is pretty strong and applicable to this usage (old one is marked with a 7).

Am I wrong? If so, please let me know and I'll get down there to replace it.

I think 8.8 should be fine Scott. That is similar to an SAE grade 5, or Suzuki's bolts marked "7".

You are going to want to loctite the bolt in place when you get that far. Degrease both the crank snout and the bolt before applying the sauce. High temperature loctite is ideal for that application - I believe the Suzuki service manual should have a recommendation somewhere.

[cowboyup3371]

Yea I picked that up before starting (red loctite) but thank you for the reminder.

[cowboyup3371]

I cleaned the crankshaft end this afternoon with Simple Green and a towel and then wiped out the new rotor. I also took the tap through the threads and cleaned out as much crap as I could see.

Afterwards, I spent some time putting the old springs, plungers, and rollers back in. For anyone else reading this, please pay attention to how you handle the rotor as they will fall back out very easily.

There is a small hole in here the spring fits into and it takes a bit to get both the plunger and the spring in there. I'm using a piece of baling wire from one of my hay bales to help push it in place.



Once the spring is in place, insert the wire through the hole in top and hold it back until you get the roller in place





Then release and move on.

Once I got downstairs and put a roller back in that fell out on me, I placed the primary drive gear back in place with the cambered section of the washer towards the engine block. I didn't replace the roller bearings inside as they felt fine so hopefully I'll be okay there.

The rotor was pressed in place. Make sure you hold the rotor in such a way that the rollers and springs don't fall out. Essentially, one spring/roller assembly cannot be directly on top as you put it on; two must be at an angle to the crankshaft rod.



Placed the red loc-tite along the last four threads of the bolt, put it in place, and torqued it to 53 foot pounds per the torque specs. I then placed the starter gear back in.





I had to turn the engine to check my shims and everything seemed to move smoothly so I'm making a big assumption that this was done right. I guess I'll know more when I finally get it running at highway speeds.

Thank you for the help everyone.

[tom203]

Great pics and explanation- big help to others understanding the starter clutch drive system. Thanks