So what would be the symptoms or dangers if it
is the bearing retaining pin? Seems to
have been running pretty well so far.
Found in my sump
- Thread starter Roger Chatterton
- Start date
is the bearing retaining pin? Seems to
have been running pretty well so far.
Could spin the main bearing cutting off oil flow through the feed hole and therefore to the crank, or could carry on running for years. The main bearing is a press fit into the bearing housing and the pin is to hold the bearing in position in the housing, this pin is suposed to be staked into the bearing housing. Behind the pin sees high oil pressure that helps to force the pin out.
Thanks v4our- looks the most likely suggestion.
Have been looking in Haynes & Clymer , and other possibility could be a
locating dowel on the con rod?
Does the size look right, or is the main bearing retainer bigger?
Inclined to agree with your suggestion though- bit of a big job for me
to replace/renew !
Have been looking in Haynes & Clymer , and other possibility could be a
locating dowel on the con rod?
Does the size look right, or is the main bearing retainer bigger?
Inclined to agree with your suggestion though- bit of a big job for me
to replace/renew !
AliBaba
Registered user
I found the pin when I replaced the sump-gasket (my bike was one week old). I didn't know what the pin was used for and threw it away. The bike ran great the first 140.000km before the problems started.
If I find a new pin I will not wait for the damage to occur
If I find a new pin I will not wait for the damage to occur
The connecting rod dowels have holes through them for the connecting rod bolts to pass through...
OK - that solves that suggestion!
Maybe get Steve Scriminger to do the necessary
over the winter.
Maybe get Steve Scriminger to do the necessary
over the winter.
TBH I'm not sure if you've agreed that it's a locating dowel, but it certainly does look like a standard locating dowel. The flat end with a chamfer is the one that is fixed in one component and the domed end protrudes so as to locate and engage the other component, typically a cover in the case of a gearbox. They are usually provided in pairs.
HTH
HTH
That's exactly the right man to do it, it's not a big job!
Many thanks for all the help from everyone, and think
the considered verdict is for that main bearing
locator pin. Only way to know for sure is
to take it apart!
Wonder what would have happened if I'd
not taken off the sump?!!! Could have been in there
for years......
the considered verdict is for that main bearing
locator pin. Only way to know for sure is
to take it apart!
Wonder what would have happened if I'd
not taken off the sump?!!! Could have been in there
for years......
Just spoken to Steve Scriminger, and he knew before I'd finished explaining that it was more than likely the front bearing retaining pin - top man ! So, taking bike up to him at some point - and get my steering bearings done at the same time.
Again, thanks for all the helpful comments, and for the correct diagnosis - don't you just love the airheads ?
Wouldn't swap it for anything else though!
Again, thanks for all the helpful comments, and for the correct diagnosis - don't you just love the airheads ?
Wouldn't swap it for anything else though!
A good result - you can sleep easy now 
.
It sounds like a potential issue that we should all be aware of.
One more item to add to the accumulated knowledge.
Bob.
.It sounds like a potential issue that we should all be aware of.
One more item to add to the accumulated knowledge
.Bob.
Yes indeed a "potential issue " ! Steve Scriminger said that it is not an uncommon event, and for him, it is an engine-out repair. He says the engine needs to be removed partly because of the heating of the timing chain cover around the bearing holder, and then then to enable correct alignment should new bearings be needed etc.
He also said that pin can get blown out of its location by ( as V4our said), by excess oil pressure. Apparently when starting bike from a very cold engine, and giving it too many revs once it has fired, can create around 200psi oil pressure (cold oil being thicker I guess), and the locating pin is vulnerable to being blown out by this sudden excessive pressure.
I think one thing to be learned from all this is that along with changing engine oil every 6000 miles or so, then maybe a Sump Removal Regime every 12000 miles ? Oh yes, and replace swivel bearings on final drive every 25000. And change gearbox oil every 6000 miles as well, not the 12000 as recommended.
So, yes, yet another thing to look out for -
So after around 40K miles in 4 years, I am on my 2nd gearbox rebuild, and now a semi engine rebuild ( well not quite but yo get my drift).
So, will report back as and when I get bike back from Steve, and wonder what else he'll find that needs replacing - suspect timing chain, tensioner, steering head bearings .....
Truly unstoppable eh ?
He also said that pin can get blown out of its location by ( as V4our said), by excess oil pressure. Apparently when starting bike from a very cold engine, and giving it too many revs once it has fired, can create around 200psi oil pressure (cold oil being thicker I guess), and the locating pin is vulnerable to being blown out by this sudden excessive pressure.
I think one thing to be learned from all this is that along with changing engine oil every 6000 miles or so, then maybe a Sump Removal Regime every 12000 miles ? Oh yes, and replace swivel bearings on final drive every 25000. And change gearbox oil every 6000 miles as well, not the 12000 as recommended.
So, yes, yet another thing to look out for -
So after around 40K miles in 4 years, I am on my 2nd gearbox rebuild, and now a semi engine rebuild ( well not quite but yo get my drift).
So, will report back as and when I get bike back from Steve, and wonder what else he'll find that needs replacing - suspect timing chain, tensioner, steering head bearings .....
Truly unstoppable eh ?
Order a pin from BMW/ Motorworks, Sherlocks, motobins and see if is the same
I had this very problem on my R80 last year - though I didn't get the warning of a pin in the sump as the pin had only worked loose enough to allow the main bearing to spin in its housing. Even though the bearing had only moved by a few degrees (see below) the result was reduced oil flow to all the key bearings - and the front big end was the part that turned out to be least resistant to this reduced lubrication, burning out quite spectacularly. Result - ruined crank.
Steve Scriminger fitted a used crank in good condition that I'd sourced along with new mains and big ends and also reshimmed the crank. he also picked the best balanced pair from the 4 conrods I'd acquired.
Cost so far: about £500.
Don't run it until this is fixed!
Steve Scriminger fitted a used crank in good condition that I'd sourced along with new mains and big ends and also reshimmed the crank. he also picked the best balanced pair from the 4 conrods I'd acquired.
Cost so far: about £500.
Don't run it until this is fixed!
Whoever lost the pin, assuming that it wasn't blown out by excess oil pressure, probably bought and fitted a new one when they couldn't find it.
If the bike is running fine I'd just keep running it.
If the bike is running fine I'd just keep running it.
Eh?
a) how would the person know that they'd lost the pin?
b) even if they had notice the pin was missing, then bought and fitted a new one, what would the old one be doing still in the sump, given that replacing this pin is an engine out job?
Keep running it at your peril.
Snowbum has more on this problem; it's far from unknown and it's certainly not trivial.
FRASERMANX
Registered user
Yikes I think I have this problem. On advrider I have been telling the sorry tale for the past while. Piece by piece I have been replacing parts, conrod bearings, pistons, barrels, piston pins, rocker arms... then onto the timing chain that many had assumed caused the noise. But now I believe I did find a pin a few years back but without problem ... but that assumption has come back to roost with heavy bottom end knocking that must be the bushing behind the bearing holder at the front of crank.
Great pix but what is it ... any further pix would be very helpful since I must work in a cold 0 degree garage
Here is a youtube video of the problem. https://www.youtube.com/watch?v=BYNd_dX6rDU
Great pix but what is it ... any further pix would be very helpful since I must work in a cold 0 degree garage
Here is a youtube video of the problem. https://www.youtube.com/watch?v=BYNd_dX6rDU
Box’a’bits
Registered user
Fraser, remove the gearbox & have a look at the clutch carrier. The 'flywheel' ring in that is rivetted on, & that sounds as if they are loose / letting go. If so, best to just replace it. You may also be able to check through the timing hole, or by lifting out the starter.
Fanum
Toubab
But they're also the ones who spout off on forums saying that you only have to put half a litre of oil in that engine, not a litre
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