Alternator drive failure

[apache]

Does anyone have any info on what I recall to be a case of early Tiger alternator drive failure. My 97 has a slight noise at the left of the alternator at about 1500 rpm, sounds like a clattering of sorts. Was this a recall and if so should a Triumph dealer be able to tell me if the recall was done by my vin##.

 Thanks.

[BR]

Apache,



You are referring to what's known as the DAR... or the "Dreaded Alternator Rattle".  Don't know about any recall I believe there are upgraded parts available.  This has been discussed many times so search the message boards for "DAR" and you'll find the info you need.  Some folks around here are quite familiar with this issue but I think a search will get you what you need.  Fix is relatively easy too I believe.  I think this was also mostly resolved in the '98 model or maybe the '97s too.. not sure.



Brendan

'98 BRG Tiger

[nightowl]

Jumping into an old post here.  Havn't checked this board in months.  Anyway when I bought my 98 it had the engine rattle, and I later learned all about DAR on the Yahoo Tiger groups.  Sounded like a diesel engine at low RPM.  There is a service bulletin out on it.  The hell of it is that the local Triump dealer's chief mechanic listened to the engine and told me they are just noisy engines.  Scary.  Anyway yes, its a solvable problem.  One of a couple of bolts securing the alternator cush drive breaks off and rattles around in its housing like a hamster wheel.   There is also a slight chance that te bolt head or washer could work its way out f that hamster cage and get into the engine so its a good idea to get it fixed.  A new bolt is cheap enough and you can get bolts of higher grade than what's in there now.  But you may have trouble removing the broken bolt from the alternator shaft.   Also I have heard of the problem coming back after a few thousand miles.  



Since its been a month since your post, have you had it fixed yet?  Yourself or at a shop?



Scott

[apache]

I decided to yank my alternator a few days ago just to check it. I was told it was replaced a while ago by the previous owner. He said it was damaged jumping the bike with a car. Anyhow, the bolt was not even in there. I cant see where it could dissapear to because theres nowhere for to hide. the dealer just left it off. nice eh? I locktited the coupler to the alt shaft with stud and bg retainer then red locktited the new bolt in to the shaft. nice and quiet now. Well see if it holds up.

[nightowl]

Excellent.  Good call on the loctite.  The posts on DAR have always said that its the bolt head in the cage making the noise but I never could believe that.  I figured it was the vane jiggling on the spline, and your experience seems to confirm that.   I think the reason the bolts break is that as the engine speed changes and the torque on the cush drive vane switches between clockwise and counterclockwise, that tiny little bit of jiggle room causes that bolt to slowly get tighter and tighter until the head just breaks off.  Then the vane is free to jiggle and the noise starts.  I used a bit of Devcon (like JB Weld) on the splines and an aircraft grade bolt.  Hopefully I'll never have to rebuild the alternator :-)  Sounds like your solution will hold up fine.



Cheers

Scott

[apache]

Is it the head breaking off??? or it just backing out?? Actually now that I think about It would seem impossible for the bolt to back out due to lack of space between the end of the alt shaft and the bolt that holds the other cush drive end on the motor. Theres no way theres enough room for a bolt to unscrew and fall out. And yes as you mention theres enough slop between the 2 sets of splines to cause the rattle. My was quiet unless you just held it right at about 1400 rpm, then you could hear the rattle.

[TigerTrax]

The bolt backs out a bit  and can break  off  and screw up your alternator.

A new alternator is $800.



When the rattling starts you need to take care of it right away.