suspension or driveshaft problem?

[Mark Kilroy]

i just bought a 93 rd dump and it feels like its bouncing alot (not from the road or the surface that im driving on),but it gets alot worse when its loanded. it feels like a driveshaft problem to me so i had it rebiult and nothing has changed, i tried alot of other possible causes like virgin tires, new drums and shoes, bushings, motor mounts but no luck...

does anyone have some other ideas?

Edited January 1, 2013 by mark93rd

[j hancock]

How about the rubber mounted center bearing on the driveshaft?

Jim

[Mark Kilroy]

thanks for the responce. i also changed the bearing when i put the driveshaft back in

[oilburner]

Could have a bent or worped wheel, if it is dayton style spoked wheels, check your spacers.

[theakerstwo]

When you have done all you can do to it pull the power divider nose of and check the peanuts and both cams for excess wear.

[oilburner]

When you have done all you can do to it pull the power divider nose of and check the peanuts and both cams for excess wear.

Not to change the subject, but we have a international eagle that does this between 50 and 54 mph, bad if it is empty, i check the u joints and found the yoke on the back rearend is very lose and sloppy, the nut is not lose it is like the splines are wore really bad it will flop around with your hand bad, Could this cause this Glenn?

[thomastractorsvc]

anything loose in the drive line can cause vibration and depending on how much movement can increase the vibration from mild to severe hop/bounce, from what I have learned, studied and come to understand, sometimes a drive line can balance itself out so that is why it is found at certain speeds or RPMs, like when you drive on concrete roads when you get a certain speed the truck will bounce on the suspension because of harmonic frequencies when you speed up it it stops or when you slow down because of the change. Loose or worn parts contribute to this and it also can cause fatigue and wear out other parts.

[oilburner]

anything loose in the drive line can cause vibration and depending on how much movement can increase the vibration from mild to severe hop/bounce, from what I have learned, studied and come to understand, sometimes a drive line can balance itself out so that is why it is found at certain speeds or RPMs, like when you drive on concrete roads when you get a certain speed the truck will bounce on the suspension because of harmonic frequencies when you speed up it it stops or when you slow down because of the change. Loose or worn parts contribute to this and it also can cause fatigue and wear out other parts.

Thanks, that is kinda what i figured, have seen u joints and things do this so that's why i was checking them, if a u joint can do it then i guess a yoke can to. but you know how it is, may put a new yoke on it tighting it up and it still do it. The only other thing i seen that was questionable were the touqe arm busings are shot also, maybe letting it walk around a little, it has the ones that go side to side, or maybe the yoke caused them to wear quicker.

[Mark Kilroy]

thanks guys, for all your ideas i will look at some of them in the a.m. at least i have a place to start

[rsb502]

I'm noticing the word bounce not vibration, I would check the wheels and axles first, if its spokes jack one wheel up at a time and spin it by hand with a hammer or block of wood or something up next to the tire when you start, watch the space between the your "alignment tool" and the tire to see if it varies as the tire spins if so the wheels are out of alignment/bent or the axle is bent and on a dump its worse loaded when there is weight on the tires.

[macattack]

thanks guys, for all your ideas i will look at some of them in the a.m. at least i have a place to start

i have been fighting a similar problem. replaced and retorqued a bunch of things. let us know what you find out. i think there are a few out there with similar problems.

good luck.

[theakerstwo]

Not to change the subject, but we have a international eagle that does this between 50 and 54 mph, bad if it is empty, i check the u joints and found the yoke on the back rearend is very lose and sloppy, the nut is not lose it is like the splines are wore really bad it will flop around with your hand bad, Could this cause this Glenn?

Yes this can cause a virbration but something is wronge with it to cause the yokes and nuts to loosen up. If a drive line is ok and the ride height is set to specs then there is no reason for a u/joint to loosen up. Some things need checked like u/joint angles and ride height as well as timing on the drive shaft plus the drive line needs to be straight and in balance.

[Mark Kilroy]

thank you all again i really appreciate all of your help. i checked a few things like the spacers and the wheels but they dont seem too bad. i tried to set the wheels true, they are not perfect tho... how could i tell if it was a bent axel? the bounce will start at or around 35mph and get less severe at 45, or sometimes at a different speed or rpm depending on who is driving.

[Mark Kilroy]

I was working on my RD today and i noticed that the crank pully was not running straight, the motor idles rough could this cause the problem? I didnt think to much of it cause my old R model ran rough and i didnt have any problems with it. IT WAS A DAMN GOOD TRUCK!!! and does anyone know the pinion angle between the transmission, front rear, and to the back rear

Edited January 8, 2013 by mark93rd

[rsb502]

was it just the pulley or the damper? if the damper is out get a new one it will save your bearings, I see you said you got the wheels close but not perfect well anything out of round or wobbling around and it will bounce, it takes time but spokes will run straight if you try.

[Mark Kilroy]

thank you again. I will try to straighten them, do i need to press for the pulley, or can i just use the bolt to put it in?

[Mark Kilroy]

Thank you all for your input. after reading thomastractorsvc's reply over and over and over i looked into it(the driveshaft). I did some research about driveshafts and found there are different types of setting. So after reading page after page of info i went back to look at the truck again and,THERE IT WAS! The front rear was set back about half to three quaters of an inch on the drivers side. off setting too imaginary parallel lines from the trans and the front rear and off setting the driveshaft. when i put the new pads in under and over the spring they sat in differently than any of the others they looked as if they didnt go all the way in but i still managed to get it back together easy but the upper looked as if it was going to squeez itself out and i didnt think anything of it. So after reading all about drivshafts and having had the problem in the past with another truck i had but a different situation it seemed familiar. so i measured from the spring at the tee to the spring seat WOOO WHOO! so we took it apart the torque arm, driveshaft, and the spring seat. With the puller we moved it foward using the lift axle as an anchor. so we put it back together and so far so good... Thank you guys for all your advice, especially Thomastractorsvc!

[oilburner]

Thank you all for your input. after reading thomastractorsvc's reply over and over and over i looked into it(the driveshaft). I did some research about driveshafts and found there are different types of setting. So after reading page after page of info i went back to look at the truck again and,THERE IT WAS! The front rear was set back about half to three quaters of an inch on the drivers side. off setting too imaginary parallel lines from the trans and the front rear and off setting the driveshaft. when i put the new pads in under and over the spring they sat in differently than any of the others they looked as if they didnt go all the way in but i still managed to get it back together easy but the upper looked as if it was going to squeez itself out and i didnt think anything of it. So after reading all about drivshafts and having had the problem in the past with another truck i had but a different situation it seemed familiar. so i measured from the spring at the tee to the spring seat WOOO WHOO! so we took it apart the torque arm, driveshaft, and the spring seat. With the puller we moved it foward using the lift axle as an anchor. so we put it back together and so far so good... Thank you guys for all your advice, especially Thomastractorsvc!

Don't you just love it when a plan comes together...Glad you got her fixed.

[macattack]

Thank you all for your input. after reading thomastractorsvc's reply over and over and over i looked into it(the driveshaft). I did some research about driveshafts and found there are different types of setting. So after reading page after page of info i went back to look at the truck again and,THERE IT WAS! The front rear was set back about half to three quaters of an inch on the drivers side. off setting too imaginary parallel lines from the trans and the front rear and off setting the driveshaft. when i put the new pads in under and over the spring they sat in differently than any of the others they looked as if they didnt go all the way in but i still managed to get it back together easy but the upper looked as if it was going to squeez itself out and i didnt think anything of it. So after reading all about drivshafts and having had the problem in the past with another truck i had but a different situation it seemed familiar. so i measured from the spring at the tee to the spring seat WOOO WHOO! so we took it apart the torque arm, driveshaft, and the spring seat. With the puller we moved it foward using the lift axle as an anchor. so we put it back together and so far so good... Thank you guys for all your advice, especially Thomastractorsvc!

so your saying it was your insulator pads in the front rear axle. did you replace all the rubber pads?

thanks

[Mark Kilroy]

Thank you again guys. Yes i did replace all the pads rubber upper and neaprene lower, the trunion bushings, the u bolts, and the torque arms, when i bruoght it home. The front rear must have walked back and when i replaced them i just put it together the same way i took it apart, but the rear was in the wrong position