The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Landlubber on June 27, 2009, 12:19:56 AM

Title: Removing the alternator rotor
Post by: Landlubber on June 27, 2009, 12:19:56 AM
I have just come in from my workshop after trying the Haynes method of removal of the rotor. I cut off a piece of 1/4 inch steel rod, inserted it into the hole and then tried to screw off the rotor with the alternator bolt inserted in over the piece of rod as instructed.

Well I tried the tap it a bit, slug it with a hammer trick and all have failed, so now I have decided to read up on where I went wrong, seems that the steel rod has to be hardened steel now I read more about this, so please can someone tell me how to get rid of the piece I inserted into the shaft. Chances are it has been bent now that I have put considerable tension onto it.

Do I have to somehow drill it out now or is there a puller that can remove the rotor without having to be inserted onto the already full hole........I am sad I did not read more about this prior to doing the job, but relied on the Haynes book as being OK. I can see now how a hardened shaft would have been so much better for the job.
Title: Re: Removing the alternator rotor
Post by: Justin B. on June 27, 2009, 01:17:16 AM
I would think you're gonna have to get it out.  You probably "mushroomed" it.  I assume you've already tried to get it out with a strong "magnet on a stick" tool?  It the rotor bad?  If so you might be able to use a regular three jaw puller on it if it doesn't matter if you tear it up...  Next up would be to try to drill and thread a hole in it and use a "slide-hammer" dent/bearing puller.

Of course, all of the above depend on how tight it's wedged in there...  :-/
Title: Re: Removing the alternator rotor
Post by: Landlubber on June 27, 2009, 03:40:13 AM
Yeah, I put a piece of brass in the lathe and made a hole in it for one of those tiny magnets, then squashed over the end, stuck it in the hole, but no result....I will phone the local BM (non dealership) fellas Monday to see what he thinks.

The bloody importer here, Morgan and Wacker,  will not work on BMW's that are over 10 years old, absolute disgrace, that is exactly why I am not buying another new BM now. I have the money to buy one but refuse to deal with someone that will not service a 10 year old bike. They are also the Hardley Driveable dealers too, same story.
Title: Re: Removing the alternator rotor
Post by: Justin B. on June 27, 2009, 09:17:07 AM
I think this 10 year thing must be a worldwide BMW thing, then, as dealers here have the same policy.  I think it very short-sighted of BMW inasmuch as a bunch of old bikes on the road is great "advertising" concerning the brand's reliability and longevity.
Title: Re: Removing the alternator rotor
Post by: Danie on June 27, 2009, 11:04:17 AM
I suppose it might  be better to use a piece of stainless steel rod, instead of mild steel when removing  altenator rotors - it will not bend as easy as a mild steel rod.

I have used a piece of stainless steel rod for the same purpose  quite recently, and although the rotor did not come loose easily, the stainless steel rod did not bent at all.
Title: Re: Removing the alternator rotor
Post by: Bob_Roller on June 27, 2009, 11:23:48 AM
There is a rotor removal tool available, and the average cost is around $6US .

One of those tools that may be worth getting, rather than trying other methods .
Title: Re: Removing the alternator rotor
Post by: Landlubber on June 27, 2009, 09:26:18 PM
Thanks all for your comments, Bob, the tool that you buy has a shaft that goes all the way into the shaft, same as the piece of syeet would have, except it is one piece, so it is too late now to insert that into the hole anyhow. The stainless steel would have been good yes, and normally I would have used that, the piece I did use was from an okd temp sender unit, I thought it woukd have done the job quite well....wrong.
Title: Re: Removing the alternator rotor
Post by: Justin B. on June 28, 2009, 11:34:22 AM
Landlubber, since you have a lathe turn a piece of stock so it will just fit in the bolt-hole in the cam snout.  Then bore/drill a hole in the center of the piece in order to make a drilling bushing.  This will allow you to easily get a hole started in the center of the stuck piece, tap some threads in it, and you may very well be able to pull it by threading a washer supported screw into it like a puller.  If not, then you can hook onto the screw with a slide-hammer and try gently yanking it out...

I made my "tool" by cutting off a chunk of appropriately sized "Allen" wrench and I suppose the shank of a worn out drill bit could be hacked off and put to good use as a puller...
Title: Re: Removing the alternator rotor
Post by: Landlubber on June 28, 2009, 05:38:07 PM
Justin, sounds good, off I go. I like the allen key bit, I may be able to hammer it into a hole drilled into the piece I inserted. Will let you know the result. Ta.
Title: Re: Removing the alternator rotor
Post by: Justin B. on June 28, 2009, 06:38:39 PM
That's not what I meant!  I made my alternator removal "tool" from a piece of allen-key...
Title: Re: Removing the alternator rotor
Post by: Landlubber on June 28, 2009, 06:40:38 PM
Back again and the piece is out. I made a bore guide as you said, started to drill into it, and decided to look into the hole as the piece started to spin after about 1mm of drilling. It was obviously off centre (the piecee was smaller than the hole size) but because it span the bit, I was then able to try the magnet on the stick trick, and out she came.

Thanks you all sooooo much, I am a happy little Vegemite again.

i am off to the BM Workshop now to use their tool.....no more risks , Ta.
Title: Re: Removing the alternator rotor
Post by: Justin B. on June 28, 2009, 07:04:16 PM
Glad you got it out OK!  You can still make your own tool but it must be something hard like an allen wrench or drill-rod.  Maybe you have an old dull 3/16" drill bit laying around you could cut the shank off from?