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View Full Version : weird vibration



catmandoo
11-06-2003, 18:54
well clutch took a crap on me on tuesday so took day off wed to fix,lost a spring off the disc and got wedged between it and pressure plate,anyway now the truck has a weird vibration. it happens at say 60 on flat road if you just have a little throttle to it to maintain speed it actually feels like a hop in the rear about 3 times a second or so if you give it (gas) it goes away or let off and it goes away.i'm at a loss thought maybe the rubber in the hanger bearing but its pretty tight and the u-joints are ok with 1 new one and i didn't separate the shafts so thats aligned. any ideas?

catmandoo
11-06-2003, 18:56
duh its a 92 c1500 ext cab 2wd hd 5spd

Kidd
11-06-2003, 19:28
Is it possible the clutch is out of balance?
Did you install a new one, or..?
:confused:
K.D.

tom.mcinerney
11-06-2003, 19:41
Cat-just a guess to throw out. Maybe the prop shaft u-joint went back 180 degrees opposite it came apart? Shouldn't matter, might. Maybe dirt under u-joint bearing cup threw out alignment? Otherwise as above comment suggests, may have to check clutch assy balance. I DO know that drive train vibes are bad news, can trash crank. These cranks are externally balanced, must have proper flywheel assy and HB, like old '400' small block.

catmandoo
11-06-2003, 19:48
ya new delco clutch and its not engine speed or at least it doesn't fell that fast and it's not as fast as wheel speed .now that i really think about it it did do this before the clutch but only once in a great while and not as bad.the one thought i have had is pilot bushing or should i say bearing it didn't fit shall i say tight on the shaft like i'm used to it did have a little slop but not much, rap a piece of paper around it and that would probably cure most of the slop. and the clutch kit did come with both a bearing and bushing. i might have to pull it apart again and see how the bushing fits.i also have this rattle in neutral push in clutch or speed up engine and it goes away and once moving it goes away, i would think front bearing but it actually has somewhat of a tinny sound like a shield or something in the trans ,the trans is the 4500 hd 5spd by the way.

catmandoo
11-07-2003, 17:34
well 250 miles today and my observations. if say i'm cruisin down the road at 60 or so it comes on kinda slow and gradually gets worse and then slowly goes away and then maybe mile or so down the road it does it again. if i feel it coming on i can back off the pedal or just push down a little harder and goes away,and if i just play with the throttle up and down but not losing or gaining speed it doesn't do it.and i also noticed it surging in second just before shift it actually feels like a gasser with bad plugwire like it's dropping a cyl,could it possibly be a weak injector.also since the addition of the turbo it seems to be surging more than before.it used to only surge after i coasted for 1/2 mile or so and then not all the time then it seemed to do it only after coasting then taking left turn,right turn wouldn't bother. now seems like about every 3rd time i take off from a stop it tends to surge somewhat .this surging feels like when it's in cold advance mode it seems to have more power, then when it pops off cold advance it just falls on it's face.thats what it acts like,could it be something sticking in the pump,or pump itself?