A cheap trick to try is to get some bar or square tube stock cut to the length of you spring between the ubolts and the back shackle. Clamp them on to your springs and then drive it.If you are getting spring wrap this will tell you. If so, then you can figure out a remedy. ie: extra leafs, helpers, ladder bars, etc.

Thanks for the advice guys.

I have concluded I have 2 vibrations or 1 thats related with multiple things.

1. The vibration when you take off is deff wheel hop as I can feel the drivers side back wheel hopping alot as I give it gas and when I accelerate on and off. Once that hops, the vibration in the frontend seems to take over. If you gun it in R its felt even worse, I can physically see it hop too.

2. There is a vibration in the frontend I think, not to sure exactly but im thinking wheel bearings, the front shaft (I cant get off right now) or the CV's or soemthing. I lean more towards the front shaft and the wheel bearings-if they arent tight enough or worn there will be slop and stuff-anyone know the check for that?

Either way the reason this is so hard to diagnose is b/c a frontend vs rearend vibe and be either or, front can have the problem but the rear you feel it and vice versa.

For front wheel bearing, lift truck, try and move tire at top and bottom.

Okay, i did that before and I thought there was play. Ill check again.

Thank you..

I THINK I SOLVED IT!

I bought some antiwrap leafs and put them on, I would say its about 80% better. Almost gone is the wheel hop on the drive wheel on take off (its there but minimal), in both Fwd and Reverse.At speed its has lessened the vibration a good bit too.

Before I tried to burn out to induce wheel hop, the drive wheel (drivers side) would hop like mad in R or D, now it plants to the ground pretty much and hooks up.

I think having the leaf springs rebuilt would be best, cause they must be weak after 200k. Im also putting on my new tires and rims, so we shall see about them being an issue too.

Controlling axle wrap wouldn't solve whatever causes(ed) it to vibrate like crazy on the jack stands because there was no axle wrap when it was on jack stands...

Well your right Erik, I did control the wheel hop I had.

Put new tires and rims on, yea there was some issues with them but it isnt it.

I think the harmonic balancer is going or gone. I looked at it and see no real wobbling, but there is a definite vibration that begins around 2900rpm and higher. In park/neutral it can be felt but since I am not transferring power to the wheels its different. I googled it and this sounds exactly like my issue, its about a 93 5.0 stang but its eerily similar to my situation:

While running w/my hand on top of the head it just doesnt feel right, at an idle it just seems to vibrate enough to be felt. Could be the motor mounts as well, or maybe even some kinda misfire-i dont know..

There is also some kinda whine, you can hear it when I rev the engine up. Now I didnt see to much wobble in the balancer or the other pulleys and belts but I could be wrong. Also, is it me of the fan pulley (or clutch idk which you call it) seem to wobble?

Video of the pulleys.. http://www.youtube.com/watch?v=2WedVQKw8Oc

Im just trying so hard to fix it, and so far its not the suspension or tires/rims. Which leaves what the harmonic balancer, engine itself (crankshaft bent??? how??) the flexplate (not likely due to no chatter from what I know) or motor mounts could be bad although the engine doesnt jump to much under load.

Honestly I am pretty close to finding some way to get rid of this thing for the best amount I can get and buy a tundra.

Still betting on the balancer. You will not be able to see it. They are either right or wrong. If you have rpm related vibes, go there.

Ok-

Does the truck make the vibration when in park or neutral, not going anywhere? If not, its not the harmonic balancer.

Only does it in gear, moving?

Next thing I'd try is put it back up on the jackstands, remove the rear shaft, run it in 2wd (front shaft shouldn't be spinning, or spinning very much- you should be able to keep it from spinning by tying a strap to it or something, or with your hand if you're careful. Or just remove both front and rear shafts.

If it doesn't vibrate in neutral then you eliminate the engine. Up on jackstands w/ no driveshafts spinning eliminates everthing after the transmission, so then its got to be something in the transmission/t-case. My guess would be the torque converter, simply because its probably the only thing big enough to make that much of a vibration.

OTOH-


This sounds an awful lot like an engine miss under load, maybe an ignition issue or maybe the timing is off. You would think the ECU would throw a code eventually though? Check the physical (belt) and ignition timing.

Well I tried to remove the front shaft to do exactly that Erik, sadly no wrench I have can get to the nuts that hold it on the engine side-diff side is no problem. I tried to remove the cross member and support the trans but couldnt get the bolts loose that hold the cross member to the frame.

I did remove the rear shaft, this produced vibrations still iirc (its been awhile). The harmonic balancer doesnt wobble either and the motor mounts seem fine to me.

I get no codes at all, period nothing. But the vibration only occurs under load while the drivetrain is spinning, HOWEVER in N or P it doesnt seem to happen as far as I can tell, no load is on the drivetrain at that time.It cannot be frontend as it wouldnt happen if the truck is 100% int he air and the front isnt moving tho-this I can tell you for sure.

As for trans, it shifts great, it has no hard shifts, it always goes into overdrive and always shifts good-worn trans components would cause issues I think-the t-case has a new stub shaft on the end that was replaced due to run out some time ago at the driveshaft shop when I had them check it. The t-case shifts well, no issues there either. Where the wheel hop is coming from baffles me as well..

Well ill try again tomorrow like I said. If I cant figure it out there is another shop I can try who are very good but costly..

Maybe I should tune it up, but a misfire should throw a code..