I have a vibration dampener that I just installed on my D333 engine. (it's on a 120, 14K Grader) I removed the old one due to what I believed to be a "wobbling" of it. I believed the the old dampeners rubber mounting looked shot so I purchased a new one and installed it. The wobbling was far reduced but still there. I former Cat. mechanic with over forty years experience said not to be too concerned. Well...I am.

Has anyone out there run into this problem? the engine runs fine and there is no unusual noices at all. I never noticed the problem before because I didn't pay any attention to that area prior to this. Let me point out one other thing. I did install a "Speedy Sleeve" on the end of the crank shaft because the old seal was leaking. When I went to replace the seal I noticed a groove in the shaft. I was wonder if the pulley which the dampener bolts to, might have road up on the sleeve a bit causing the pulley not to seat on the shaft exactly squarely. But again...the sleeve is so thin to begin with and the chance of offset is seems to be very small, if at all?

While the pulley was off I did check to see if ther was any bearing problems on that end of the shaft and it seemed tight, including horizontal movement. (engine has very few hours on it since rebuild, but it did sit for many years) I also haven't mic'sd the pully but I did look at it close and used a pointing device to see if it was running true and it seemed perfect. Well...any ideas? Should I be concerned?

Is it the outer section wobbling on the inner or is the whole thing wobbling? I have installed a lot of those speedy sleeves and never had one try to ride up as you suggested. The damper hub should have pushed the sleevein furthur. I also think if it would rode up on the sleeve the hub would have broke when torqueing the bolt in the end. If the outer section is wobbling a little on the inside don't be alarmed. I've seen a lot of new ones do that on the older rubber style damper.

Hi Mark,
That is a torsional vibration dampener used to help cancel out torsional movement (twisting) of the crankshaft and if it is doing its job there should be some movement. You were right in replacing the old one as the rubber ring deteriorates over time losing some of its elastic function. In extreme cases they have been know to separate and allow the flywheel ring portion to come off. As it is not a precise item you can also expect some run out.

Not very likely you would have any influence with the speedy sleeve as the pulley is on a tapered shaft with a hefty torque (210-250 ft-lb) retaining bolt.

I would keep an eye on it for awhile just in case there could be a manufacturing problem but otherwise I wouldn't worry about it.

Mark
I had a concern about the damper on the 3406B in my truck, so I talked to the service dept at Milton Cat. Both the service manager and one of the truck engine mechanics said that as long as the two marks on the damper, one on the inner hub and one on the outer ring, stay lined up, the damper is OK. Cat allows for 80 thousands runout on the outer ring before recommending replacement. they told me even if it wobbles, it is OK, but to "keep an eye on it" Made me feel real comfortable. That was 4 or 5 years ago, and it is still OK. I don't know if the same is true for your D333, but it probably is. The new style for mine is one piece, without the rubber ring inbetween. If you have an engine service manual it should be listed in the specification section.

George

Thanks for the answers. The "wobbling" is certainly visible and I do not have a manual on this engine, yet. Is the runout 80 thousandths? Not sure yet. Need to dial indicate it first. But that is a lot. For some reason the 14K 120 grader service manual is not available? So I'll have to get one just for the engine. But it's ONLY the outer ring that seems to be moving (of course). I checked the inner ring for movement and it is running true. As a licensed Marine Engineer I know fully what the purpose of the dampener is. It's just that in the course of my work and training I've never run into a rubber mounted dampener for this purpose. (worked on mostly 398/399 Cat's for generators prime movers and 5 cylinder Sultzer engines for propulsion) Live and learn I guess. If anyone has a manual for the D333 engine on my 1969, 120, 14K1608 grader I would very much appreciate any tolerance info. you can provide, concerning this dampener. My 12E has a solid dampener and so does my 70D. So those manuals are no use here. I'm thinking, now after "talking" with you guys, that it may well be just fine.

So..thanks again everyone, for all the info. and help! It's much appreciated.

Hi Mark,
I looked up the dampener info in the 76A1 D6 tractor service manual. This model uses the D333T engine up to 1968. I don't have later model manual to 1969 (96A) but anyway although there is brief mention of the dampener I could find no specifications as to allowable run out.

Usually they never give you a problem unless they come apart the they need replacing. The old D386-D397 V-12 engines & the V-8 versions (D375-364) they had a fluid filled damper on them but you had to be careful not to distort or dent the surface in on them & they lasted forever it seemed.

The rubber vibration dampeners often get a wobble to them, but I've never seen any specs on runout for them.
The problem is, they are a 'cheapie' dampener, with the two sections just pressed together, with the rubber section compressed between them.
They can come loose, and fall off .. and oil dripping on them, is their worst enemy.The oil softens and lubricates the rubber, and heat adds to the problems.
If the wobble worries you greatly, you could always remove it, place it in a shop press, and apply pressure in the right area, to re-align the outer section with the inner section. Its likely that the two sections have not been properly pressed together from the factory, but if its new, you should not have any problems.

I'm just not use to seeing precision rotatings parts "wobble" while in use. Seemed to me to indicate a problem. But from what I've learned about these rubber mounted dampeners, it's somewhat normal. I'll just "keep an eye on it" and see what happens. I want to thank all of you who've replied. Thanks!