np203 vibrating after 55mph!

[Kapdin]

So I know the 203 is chain driven and I've heard that that chain can stretch. I don't know when ill get a chance to swap in a 205 so would like to see if I can get my 203 under control. But any ways would that chain cause my vibration? i can feel it in the floor but really feel in when i grab the shifter. Both drive shafts have new u-joints and greased so im pretty sure its not thos. Its also full of oil. Is there a tensioner in there or.... am i just screwed?

 

[bucket]

When did the vibration start? You said recent u-joints, probably should check them and make sure all the clips and caps are still in place. Also check for excessive slop in the slip portion of the shafts.

 

[Kapdin]

it has always vibrated but it got way worse when i went from 3.08s to the 4.10's cus im sure that drive train is turning much faster. i just pulled the rear drive shaft off the other night and inspected it and made sure the clips were right and greased up good. I had also had it backwards (long story but had a write up as to why in a diff forum) but now have it turned right. and i don't feel much movement at all in the yolk. And the front drive shaft is solid as a rock, I also have gm original u-bolts and straps for the joints.

 

[bucket]

Oh, a stretched chain shouldn't cause a vibration. Every one I've dealt with caused a bad popping sound while accelerating.

 

[Kapdin]

the vibrating noies goes in pulses too if u get wat im saying..

 

[bucket]

it has always vibrated but it got way worse when i went from 3.08s to the 4.10's cus im sure that drive train is turning much faster. i just pulled the rear drive shaft off the other night and inspected it and made sure the clips were right and greased up good. I had also had it backwards (long story but had a write up as to why in a diff forum) but now have it turned right. and i don't feel much movement at all in the yolk. And the front drive shaft is solid as a rock, I also have gm original u-bolts and straps for the joints.

It could just be a shaft that needs balanced.

 

[Kapdin]

hum... fugg, and i have no issues at all (hard acceleration, cruisin under 60, pullin) 4hi, 4low all the same.

 

[bucket]

the vibrating noies goes in pulses too if u get wat im saying..

Yeah, like the vibration slowly but repeatedly fades in and then fades away, over and over.

Have any driveline shops nearby? There's a couple places around here that will balance a shaft for around 35 bucks.

 

[HotRodPC]

Yep, sounds more like driveshaft issues. And you're sure you're wheels are not the cause from maybe bad leaf spring bushings or out of balance, or even U joints at the hubs?

 

[Kapdin]

HR, u bring up a few things i guess i never checked, the rear leaves are like new if u remember me scoring thos but the fronts yea the bushings are a bit rough but all there and very tight when i put them in, ive had the truck aligned but tires never balanced but they were balanced when they were on the 02 i stole them off of. The u-joints at the hub's ive looked at but never really messed with. I'm going to ask around to find a shop that will balance my drive shaft and start there.

 

[Kapdin]

Yeah, like the vibration slowly but repeatedly fades in and then fades away, over and over.

lol yes exactaly.

 

[crazy4offroad]

If you ever had the slip joint apart on either of the driveshafts they could be out of phase if you didn't put them back exactly like they came apart. The yokes should be aligned, if you did take one or both apart make sure they're in phase. If they are aligned make sure you didn't put them back together 180 degrees out. Also you may try taking the driveshaft loose from the axle pinion, rotate it 180 degrees and bolt it back up and see if it helps.

 

[Kapdin]

If you ever had the slip joint apart on either of the driveshafts they could be out of phase if you didn't put them back exactly like they came apart. The yokes should be aligned, if you did take one or both apart make sure they're in phase. If they are aligned make sure you didn't put them back together 180 degrees out. Also you may try taking the driveshaft loose from the axle pinion, rotate it 180 degrees and bolt it back up and see if it helps.

huh, did not realize they needed to be aligned... so no im sure they are out of alignment. I also have that combo joint at the rear. So how should it be? just matching perpendicular?

 

[crazy4offroad]

Doesnt matter the position of the combo joint as long as the sizes are right, a 1310 and a 3R are very similar IIRC but one is a little shorter which would allow maybe 1/8" of slop. And yes looking down the driveshaft both yokes on the driveshaft need to be in alignment.

 

[Kapdin]

I'll start there, thanks. Did find a shop that would balance also but hope i won't have too.