Lower Timing Chain Blew-up!!!!!!!

Balmy 38 today huh....

Look at it this way. You pay extra for air conditioning in your car and you get it for free on a bike in cool weather.

Keep on riding that sucker.........proper attire is not optional. It's required.

Humans

Just finished replacing the lower sprocket and heres my 2 cents worth. Feel like I wasted my time because the new sprocket looked just like the one I took off. They have not changed any thing except a small ring indent that you can hardly feel with your finger nail.(PICT IN NEXT POST)The bolt holding it to the crank was so tight it took a 3 foot extenson on the # 6 allen to break it loose.Someone on the line must have stood on the torque wrench,if they used a torque wrench.Way more than the 20 ft.lbs the book calls for.There is no wear or rounding of the key corners or crank or sprocket. Looked brand new..I think that the problems and failures are from the bolt not being torqued enought and would start to loosen and wobble causing the destruction..Once more human error is at fault like the bearing in the final drive installed backwards and all the loose bolts and nuts over the entire bike.If you have the popcan rattle retorque the bolt through the access hole above the oil filter.This just may save a trashed engine.Someones dealer here told them to hold a screwdriver on the cam chain guides through the tensioner hole.Ha If you slip off the guide the chain goes slack and will jump the lower timing sprocket and cause the same damage as the sprocket comming off.Dealers HAHAHA----Crazy Jack

Jack

I'm wondering if the new sprocket is heat treated differently. For the old one to wallow the keyway out (that seems what is going on anyway), the bore would have to be softer than the key itself. That would only be conjecture unless you took the old sprocket and the new sprocket and did a Rockwell penetration test on the bore area. That would tell you for sure. That could be easily done without any damage to either sprocket other than the very small indentation where the point indents the material.

Sounds like the hex cap was put on with a torque limiting air tool, with the limiter screwed shut. Just like the factory oil filter install. You have to jam a screwdriver through it to get it off. QC at it's best. I wonder if the guys at the factory are recycled US Gummit employees?

----I think your right Flip. This is the old sprocket,I put a mark where the new one has a slight indent which is probably to indicate differn't heat treating. Then again the failures are sporadic from 05 to 07. I think human error and a softer heat treatment are responsible. But what the hell do I know Iam an x goment employe who cant spell.Th ha ah. Conclusion, wasn't nothing wrong with mine, no noise but the peace of mind makes me feel better.The new sprocket was only 58 bucks and them blokes need the money..Crazy jack

Jack

Well they just had another sprocket split in three pieces on an 07 over at com.So I guess that shoots down my theory about not being tight enought.Wait mabey not.It could start moving around and bind then split..Hmmmm Jack

Very interesting....

I like your paper towels.....Bounty or Scott? That's a specialty key, not anything listed in Machinery's Handbook. I also see that there is plenty of 262 or 271 Threadlocker on the hex cap which probably explains why it was so stubborn to remove. 62 or 71 require a pre-heat of the fastener to ease removal and I suspect it's probably 271. The 71 spec is pre-heat to 300 degrees and/or impact removal. I'll have to retract the wise ass remark about the air tool being screwed shut. It was most likely 20Nm but after the threadlocker crystallizes, it's balls to the wall to get 'er off.

Little design differences can make a huge difference in the end result. Just like the KLR 650's. Kawasaki gets the piston/ring assemblies from 2 different suppliers. One of the suppliers' assemblies consistently burns oil at high rpm and the other don't. Same specs, different suppliers. You buy the bike and take a chance. Kawasaki stands behind the engine and will rebuild the top end if it burns oil so Triumph seems no different.

I know you are very conscientious Jack, but did you check the chain to make sure it wasn't wearing uneven and there are no binding links?

Least you have peace of mind at this point and you've communed with Spike.

Yea Flip,I used my hobby magnifires and the chain barley even had contact marks.The manual has a very good ck. list for checking the chain. I just can't figure why 07s are comming apart. They should know by now which suppliers are at fault..They should have made that sprocket out of hockey puck rubber. Jack

yeah I got the rattle at 5000km on my brand new07 classic, it's been in the dealers now going on 7 weeks, rear bearing crapped itself, waiting for parts I'm told. Timing chain was also mentioned as an ongoing problem so were talking about sending out some sort of pack and replacing all of these on going probs at once... F***k knows how much longer I'm gonna av to wait, Christmas is nearly here, not looken good havent a bike to ride, and missed the toy run!!! pull your finger out triumph!!!

busajack said:

Yea Flip,I used my hobby magnifires and the chain barley even had contact marks.The manual has a very good ck. list for checking the chain. I just can't figure why 07s are comming apart. They should know by now which suppliers are at fault..They should have made that sprocket out of hockey puck rubber. Jack

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I'm hoping my new KLR don't have the bad piston.....................

Interesting you mention hockey puck. Everytime I envision a puck I see (in my minds eye) Goofy at the hockey game eating a hot dog and a player hitting the puck and it knocks Goofy's hot dog and bun away and the puck replaces the hot dog and Goofy takes a bite of it. I know, I have cabin fever.