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1772 vibration

Posted: Sat Apr 02, 2016 8:48 pm
by JoeK
Ok guys i got to ask the all important question to you diesel owners out there, how much shake is too much and do i have other problems!

To start off with i have rebuilt my driveline with new rubber and a new shaft, new coupling for the pump. When i had everything off i started the engine and i still got some good vibration there, now i do have some bolts that are wrong on my driveline the ones that bolt to the rear of the engine that holds the end of the shaft and one that hold the rubber on hit. I'm sure there is a small head bolt in this location or possibly this piece may be welded wrong ether way there forcing the rubber to not be straight, i think this is where my fine vibration is coming from, the kind that makes your legs numb would be the only way to put it. so... do i try get new motor mounts to try get rid of engine vibration is there a vibration dampener for this engine D640? could i have a bad injector?? seems to run just fine for a IDI , is it possible that there is an alignment issue?? where do i start to look next??
Now i work with diesel grasshoppers and those things run so smooth its not even funny how much mine shakes compared to them even the ones with 2000= hours are so smooth . Any thoughts i spent a lot of time working and worrying about my baby i don't want take it out and wreck something i cant replace. Could all this be in my head I'm not sure, but when the top of my exhaust stack is a blur through most of the rpm range with the hood rattling around kinda has me on edge thinking i missed something. And with that, let the comments begin :beer:


unrelated: these glow plugs are supposed to get 12 volts correct? I'm getting around 9 when turned on. normal??

Re: 1772 vibration

Posted: Sat Apr 02, 2016 9:44 pm
by dag1450
Joey...u know more than most of us about how a diesel should feel....and it sounds to me u have answered your own question. U seem to have a problem. Start stripping it back of all extras so u just have the engine. Mine has not run in a few years....but from what I remember it was not rough. I could not find the u tube vid I wanted.....but if u search cub cadet diesel or cc turbo diesel ...there r a few vids of engines running and u might be able to get a feel of there shake. The couple I watched looked darn smooth. Is this vibration new or ever since u owned it. New motor mounts? Fan off balance? Do u still have the driveshaft clutch? I heard guys don't like them. Mine was fine but there r weights in there. Good luck

Re: 1772 vibration

Posted: Sun Apr 03, 2016 9:20 am
by JoeK
Its always shook since i had it, its better since i rebuilt the drive line with the exception of the sharp vibration. As far as you-tube goes i have looked at all the diesel cub vids and mine is nothing like them, I cant even see those shake. the more i think about it i think i must have something missing for a vibration dampener or a weighted fly wheel or something. idk ill have to ask around i guess. a coworker thinks it is fine , says his 2072 shakes worse. but im not sure. there is an engine shop across the road from where i work and i hear they have one of these engines sitting there with a turbo, i may just go over and take a look at it and compare parts and talk with the owner once.

Re: 1772 vibration

Posted: Sat Apr 09, 2016 7:59 am
by drcjv
Do you have a clutch in the drive shaft? Secondly if the drive shaft is not lined up properly I think that needs to be corrected first. My 1572 started to vibrate badly. My problem was the clutch and a worn charge pump shaft. I replaced drive shaft with a newer style u joint shaft and replaced charge pump shaft. Now very smooth.

Re: 1772 vibration

Posted: Sat Apr 09, 2016 10:24 am
by Tom Scott
JoeK wrote:...now i do have some bolts that are wrong on my driveline the ones that bolt to the rear of the engine that holds the end of the shaft and one that hold the rubber on hit.
Go after the obvious stuff first. You can't have anything "hitting" as it operates. If you can't find a standard hex head bolt that clears, perhaps a socket head (allen head) might correct that issue. Just be certain any new bolts are Grade 5 or better. Yes, everything should clear with all factory parts, but one of mine (can't remember which tractor now :oops: ) had issues with the bolt heads being too large and were rubbing. Both of my 2182''s needed the engine mounts retorqued as well.

The spherical balls in the couplers can wear and even the driveshaft could be worn or bent. I find good troubleshooting can be thought of as methodically proving each item conclusively "ok" before moving on to the next. Only make one change at a time to be sure of the result.

Re: 1772 vibration

Posted: Sun Apr 10, 2016 9:02 am
by Farmallgray
I know on mine it vibrates more at certain RPMs. It vibrates pretty good at idle but at about 1/4 throttle it smooths right out. As mentioned, the spherical bushing at each end get worn and can allow the shaft to whip rather than spin. Does the shaft appear to spin true when running?

Re: 1772 vibration

Posted: Sun Apr 10, 2016 6:30 pm
by JoeK
everything from the engine back is new but not saying anything could be out of whack, those rubber disks is there a proper way to center those? other then tighten one side then the other?. ill try get a picture of the bolt and how it this this week sometime. i have had this engine running with out the shaft months before rebuilding and still shook so i am going to start with motor mounts i think.

Re: 1772 vibration

Posted: Sun Apr 17, 2016 10:59 am
by JoeK
Picture of where my vibration was coming from, some how managed to get a die-grinder in there and made some space between the heads and now runs a lot smoother. I did order some new motor mounts as well to try get whats left of the vibration. hope it works those motor mounts were not cheap. :cry:

Re: 1772 vibration

Posted: Sun Apr 17, 2016 8:08 pm
by dag1450
That's great Joey! Could u elaborate a little more on what was causing the problem. I really can't make out what your picture is of? :shock:

Re: 1772 vibration

Posted: Sun Apr 17, 2016 8:27 pm
by JoeK
Why yes, yes i can. What your looking at in the picture is the coupling between the engine and the drive line, the bolt heads that you see touching are what hold the bushing for the end of the driveshaft and the rubber flex disk, somehow they line up just right making me wonder if there is special bolts for that. In addition to cutting the bolt heads down i trimmed the bolts down to length as it seems once i took the flex out of the coupling they hit the steering hand pump some how at high revs just every so slightly.

Re: 1772 vibration

Posted: Mon Apr 18, 2016 11:36 am
by dag1450
Not sure on the diesel.....but on most if not all cubs, those bolts would b like 90° different. So one set would b at like 12 & 6.... the others would b like 3 & 9. Idk but something don't sound right in there.

Re: 1772 vibration

Posted: Mon Apr 18, 2016 7:42 pm
by JoeK
The round plate that holds the end of the shaft has 3 bolt's that bolt to the crankshaft there is only one that lines up like this, the other one i replaced was also like this, I will try get a picture of the one i removed and post it on here.