SuzukiSavage.com /cgi-bin/YaBB.pl General Category >> Rubber Side Down! >> HARD KNOCK SOUND /cgi-bin/YaBB.pl?num=1662408444 Message started by YODEX on 09/05/22 at 13:07:24

Title: HARD KNOCK SOUND Post by YODEX on 09/05/22 at 13:07:24 Hi i just got a savage and it has a hard knoning soun coming from the center of the engine, i jut took it apart and foun that the Crankshaft has lateral movement, ithat ok? because when i move it its like the clank sound but not that loud. Chain and valves are ok, camshaft and rockers ok, the bike was runing ok but the the sound.

Title: Re: HARD KNOCK SOUND Post by YODEX on 09/05/22 at 13:07:51 video here a video https://youtu.be/Io-Vk_HZ75k. Any hel wil be apreciated.

Title: Re: HARD KNOCK SOUND Post by DragBikeMike on 09/05/22 at 14:56:39 Wow!  That's some major axial movement.  Thanks for the vid. You have a very loose fit on your right-side main bearing.  The right main bearing is a ball bearing.  It controls the lateral movement of the crank.  By design, the outer race is a heavy press fit into the crankcase, and the fit between the crankshaft and the inner race is a light drive fit.  The crank is pinched to the inner race by the primary drive gear nut (Left-hand threads). The movement shown in your video could be caused by a loose fit between the right-side main bearing outer race and the crankcase, or a loose fit between the inner race and crank combined with a loose primary drive nut. Correction of either will require complete disassembly. A mickey-mouse fix might be accomplished if the problem is related to the loose nut/loose inner race fit.  Tighten the nut and sell it (pretty dirty trick). Note that the normal crankshaft thrust is toward the right.  That's true under both acceleration and deceleration.  The crank always thrusts towards the right. Unbelievable movement on yours.  You also want to make sure that your cam drive sprocket on the crankshaft isn't shattered, and your balancer drive pin hasn't worked loose.

Title: Re: HARD KNOCK SOUND Post by DragBikeMike on 09/05/22 at 15:02:17 This is what the shattered cam drive sprocket looks like.  When it shatters like this, the primary drive gear nut no longer pinches the crankshaft to the inner race of the main bearing.

Title: Re: HARD KNOCK SOUND Post by DragBikeMike on 09/05/22 at 15:06:38 This is what happens when the balancer drive pin comes loose.  See the pin circled in red.  When it comes loose and falls out (as shown), the balancer timing is lost, and the counterweight collides with the rod.  I personally believe that this failure was a direct result of a shattered cam drive sprocket.  Others may have a different opinion.  I think you need to check this stuff on your engine.  You definitely have some loose stuff.

Title: Re: HARD KNOCK SOUND Post by DragBikeMike on 09/05/22 at 15:10:53 As you can see, you don't wanna let this go.  The results are disasterous.

Title: Re: HARD KNOCK SOUND Post by YODEX on 09/05/22 at 15:35:09 1B1D126E6C6B6F5F0 wrote: Wow!  That's some major axial movement.  Thanks for the vid. You have a very loose fit on your right-side main bearing.  The right main bearing is a ball bearing.  It controls the lateral movement of the crank.  By design, the outer race is a heavy press fit into the crankcase, and the fit between the crankshaft and the inner race is a light drive fit.  The crank is pinched to the inner race by the primary drive gear nut (Left-hand threads). The movement shown in your video could be caused by a loose fit between the right-side main bearing outer race and the crankcase, or a loose fit between the inner race and crank combined with a loose primary drive nut. Correction of either will require complete disassembly. A mickey-mouse fix might be accomplished if the problem is related to the loose nut/loose inner race fit.  Tighten the nut and sell it (pretty dirty trick). Note that the normal crankshaft thrust is toward the right.  That's true under both acceleration and deceleration.  The crank always thrusts towards the right. Unbelievable movement on yours.  You also want to make sure that your cam drive sprocket on the crankshaft isn't shattered, and your balancer drive pin hasn't worked loose.   Thanx for the reply i just open it and the rigth bearing fits easy so you can move it, i think that they did a repair and insted of fresze the bearing to resamble they hit it so the case lost the ability to hold it, ill try to ensable using a bearing retaining compound as locktite i hoppe it works. The nut on the inner face was ok

Title: Re: HARD KNOCK SOUND Post by YODEX on 09/05/22 at 15:40:47 5B5D522E2C2B2F1F0 wrote: As you can see, you don't wanna let this go.  The results are disasterous. the pin was ok and the balancer didnt touch the crankshaft, but i can see that the balancer bearin also has some play.... ass i can the by looking the bearins is that they change them because one is KOYO and the others no brand... i think ill have to do the same with the retaining compound and if it doesnt work i think that ill have to fabricate a kind of metal sheet to adjust the lateral movement...

Title: Re: HARD KNOCK SOUND Post by TheSneeze on 09/05/22 at 16:31:24 Best of luck with this one.  Keep us posted.  So many great guys on here, you won't be steered wrong.

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