ST1100 40 amp alternator removal

[BillyBob]

You might find on a high mileage bike that whatever means used to line up the split gear in the drive unit, the crank may not stay stationary due to old age, so preventing it rotating by locking it in gear as in my method may need to be done. My old White Pan had 200,000 miles plus when I repaired my alternator, which had siezed and cracked the case due to water ingress, common on Pans used daily in all weathers. Mine had two careful owners before me, the Police and a Courier

 

[Hound]

Nice job BillyBob!

 

[D1now]

Hi all. Sorry I have been quiet recently, trying to get my damn alternator drive unit back in. I have tried all methods and am really struggling to get the damn thing to go back in.

 

[BillyBob]

Exactly what stage are you at?

I assume you have replaced the bust Alternator or repaired it (I repaired one once it was a bugger of a job.) Therefore at some time the two parts have been seperated. If still apart then putting the drive unit back into place by twisting the split helical gears back into alignment by using the stick method or using the tools method described previously should work. Once the drive unit is in place but not secured then the Alternator can be wiggled back into contact and the two parts secured back to the engine case. The Alternator body will not engage without maneuvering unless the engine is out because the frame prevents it.
I don't recall whether or not the complete assembly will go in using the split pin method which is the long winded way unless you are doing an oil change or removing the sump for another reason, it was a long time ago when I fixed mine.

 

[D1now]

Hi. I am at the stage of trying to refit the drive unit. Whatever I try it does not want to drop into it's "hole". 3 of all at the same time yesterday; one was keeping the wiggle on the spline receiving bit, one was trying to get the drive to seat and advance in, and one was looking to check alignment whilst keeping the engine locked from turning. I will be trying again in a few minutes.

 

[George]

I knew I had read this was possible, never tried it myself. Hope this is the solution.

 

[D1now]

I am celebrating! After a couple of hours of wiggling, swearing, etc. It popped in. I have no idea how, but it did. Alternator now fitted! I will never allow the drive unit to come out of the engine ever again! Thank you all for the support.

 

[Oldbikefixr]

I am celebrating! After a couple of hours of wiggling, swearing, etc. It popped in. I have no idea how, but it did. Alternator now fitted! I will never allow the drive unit to come out of the engine ever again! Thank you all for the support.

Just the Universe at work...'Think I've *&^%ed with this guy long enough'.

 

[BillyBob]

When you push the drive unit in by hand it will stop when the split gear makes contact with the gear it is driven by on the crankshaft. So while holding pressure and twisting the internals just a smidgen the unit will slide into place when the split helical gears are aligned. Tidy..

If you wonder why this arrangement is used by Honda, then apart from peeps pulling there hair out refitting it, it makes it nice and quiet.

Take it out and practice again!!! I'll get me coat.

 

[D1now]

Indeed and the theory of how it goes back in is well understood by me, but it proved to be an absolutely atrocious task. I will never remove it again. Simple.

 

[Jim Van]

BTW, I thought I'd mention that I now have about 15K miles on my Chinese alternator w/o any problems. I hope this post doesn't jinx me.

 

[ST1100Y]

BTW, I thought I'd mention that I now have about 15K miles on my Chinese alternator w/o any problems. I hope this post doesn't jinx me.

Yep, I'd also installed one in the '94, the pattern looks like the perfect twin when holding it side by side with an OEM 40A unit... working perfect