Sprint ST's Breaking Crankshafts ? Surely Not!

[steevg]

Hey Guys!

A Couple of questions for you technical people out there:-

1) I received this from a guy with a 2002 Triumph Sprint ST  -  

"I have discovered that the 02 sprints have a tendency to break crankshafts, this seems to be due to the starter clutch becoming loose.
There are several documented cases of this and unfortunatly I didn't know
about it which is why my sprint is on a truck as I write this.
The problem is easily checked by undoing the 17mm bolt on the right side of
the bike and making sure the bolt is tight. "

What's he talking about (which 17mm bolt?) and how do I check to see if my 2003 model has a problem?

2) My 2003 Sprint ST was imported (I'm in NZ), and someone in their wisdom saw fit to cover the chain in thick black grease ( I mean REAL thick) - it's everywhere - what do I use to clean the bike up? I understand that I have to be careful not to "wash" the chain, as I might be in danger of removing the lube in the chain rollers?

Any help on the above would be much appreciated.

Regards,
Steve

[garry]

I think I read about his case of a crankshaft failing somewhere on the web. Spit happens sometimes. Perhaps its worth checking to be safe, but I don't think it's a widespread issue. I was a Triumph RAT Pack leader for the last four years and participated actively on many a Triumph/Sprint forum and his was (I think) the first I'd read about.
 
RE: Chain. Just use a rag and/or brush soaked in kerosene to clean the heavy grease/grime off the chain, wipe it dry, take it for a short ride to warm the chain and fling off any residual kerosene, then lube well.

[DennyMoto]

On the TriumphRat.net forums ...
 
http://www.triumphrat.net/modules.php?op=modload&name=Forum&file=viewtopic&topic=55796&forum=20

[Playinthestreet]

About the third page into that post the guy admits he's changed a good deal of the computer program as well as increasing the rev limiter.  In that case it seems he's his own worst enemy.

[steevg]

Garry,
Thanks for the info - but won't kerosene affect the lube in the chain rollers?

(My "email notification" of replies doesn't seem to be working?).

[garry]

Kerosene (aka paraffin in the UK) is what Triumph recommends in the owners and service manuals for cleaning the chain. You're not soaking the chain in it, just using it with a rag to get the gunk off. The lube is sealed inside the rollers by little O-rings, so as long as you don't use a cleaner that eats the O-ring up, you're good to go.

[DennyMoto]

won't kerosene affect the lube in the chain rollers?

Nope.  The o-rings are the important thing.  Whatever you use to clean it must not be detrimental to the rings.  The lubrication can be replaced by simply oiling the chain.

[steevg]

Excellent guys - thanks a million, I was a bit worried about this but now I understand what's going on I can get to work cleaning all the crap off the bike!

Oh, anything else I should be doing while the bike has all the fairings off it?

Thanks,
Steve

[garry]

Oh, anything else I should be doing while the bike has all the fairings off it?

Make sure any recalls have been done. Plastic quick-disconnect fuel connectors replaced by metal ones affected all fuel-injected Triumphs I think. I believe the 2002 STs had a recall on a swingarm bearing (didn't apply to double-sided swingarms like the RS had).

[sprint_st]

If you read the complete thread listed above there were at least four guys with broken cranks, and reference to possibly 7 more in the UK.  All were in the 30-40K mile range and all had something to do with a loose sprag clutch fixing.  If you are worried about it, you can do what I did and pull the inspection cover off the right end of the crank and see if the "fixing" (looks like an allen head bolt to me) is loose.  It's easy to do and I will be doing it at every oil change or whenever I'm in the area.  If you have an 02-04 955i and you had valve shims swapped, I would take a look at it.  If it is loose, the bolt needs to be replaced and use loctite to make sure it doesn't come loose again.  If you are doing the fuel line quick disconnect swap to metal, I highly recommend getting a kit from Team Triumph.  The Triumph metal replacements are crap.  You can take your VIN to any Triumph dealer and they can get you a listing of all recalls that have been performed by authorized dealers on your bike.

[stk0308]

And just for discussion sake I have a rather abused '02 with over 76k miles on it.  And it's original crank.  The only people who have been in the motor, valve adjustments, and replacing one failed charging rotor, has been a dealer mechanic.  Just saying, it's not every one, just a few.  It would be interesting to see the build date/vin #s of those that have failed.

[sprint_st]

And just for discussion sake I have a rather abused '02 with over 76k miles on it.  And it's original crank.  The only people who have been in the motor, valve adjustments, and replacing one failed charging rotor, has been a dealer mechanic.  Just saying, it's not every one, just a few.  It would be interesting to see the build date/vin #s of those that have failed.

That question was asked on the thread but the VIN's are different in UK, US and OZ where they occurred and it was hard to decrypt.  One other thing is that most of them did not work on the bike themselves but took them to dealers.  IMO, guys who work on bikes themselves tend to be a lot more picky about getting things right.  About a year to two years ago there were also reports of earlier model Sprints having crank fails at about 70K miles and they were also scattered and rare.