testing driveshaft

just a quick question, can i take the driveshaft off and put the truck in 4hi to see if my vibration is really coming from the driveshaft or not? i am at my wits end with this vibration problem, so i am thinking if i take off the driveshaft and drive the truck a short distance without it then i will know for sure if it is the rear end or not that is causing the vibration. just a quick yes or no would be great, cuz i would like to take care of this today. thanks!

How are you gonna keep the front yoke in?

im just going to remove the whole driveshaft with the yokes

And you're going to keep transmission fluid from coming out of where the front yoke was how?

im just asking, i dont really know a lot about rear driveshafts. i do know how to take out the driveshaft though, and i wasnt sure how it would work or if it would work if i took the driveshaft off to test it.

If you take it out, you'll drop most of your tranny fluid.... Your better bet is disconnect it and have it's balance checked, and check the u-joints.

yea, i figured it wouldnt be that easy as to just take out the shaft and test it, but yea i already had the shaft balanced and both u joints replaced. any other ideas then as to what it could be? because i took it to the local aamco and pep boys and they both said they have no idea whats wrong with it, the axles are not bent in the rear, the bearings are fine, the u joints were both replaced, and the driveshaft was balanced so they are stumped... :( i just want my truck to ride smooth, its been such a pain trying to figure out what this is and nobody has a clue, but i really dont think im the only one who has had this problem before so im sure one of you guys on here can help me, thanks!!

wait a minute though, how come when i take the driveshaft off the fluid doesnt come out when i do that? is it because the truck is just sitting still and not moving?

Pretty much.... The moment that the tranny is engaged, pressure will force fluid out of where the yoke was.. That said.... Check for seperation on your motor mounts, check your tranny mount. Also check to make sure none of your bell housing bolts are loose. Where exactly are you feeling the vibration, under your but or through the steering wheel?

definitely can feel it under me. i should note though, that when i had the driveshaft balanced the guy said there was definitely some runout on it, what is runout and could it be causing my problem? is there a way to fix runout if it really is the problem?

bump... :)

check your tranny and transfer case mounts.

Get your rear tires checked for shifted belts and have them balanced.

so does anyone know what runout is and is it bad for my driveshaft?

what runout?

when i had my driveshaft balanced the guy said it had some runout, thats all i know. i was thinking and from reading around the forums that runout may mean my driveshaft is bent?? if so thats definitely finally what my problem is...

Means you had some transmission fluid come out your tail shaft which is normal.

Check your transmission fluid level with the engine idling in hot park.

He was just informing you that you might have to top up the tranny fluid.

i dont think thats right... i just brought him the driveshaft separately, i didnt bring him the truck. i took the shaft off and brought it to him and when i went to pick it up i asked him if there were any problems with it and he said there was some runout, cant be anything to do with transmission fluid because i didnt even bring him the truck. anyone have any other ideas?

I would talk to him again and ask for clarification.

we can't tell you what he meant because it could have been his own wording.

run out=twist warpage... If he was able to spot that, the drive shaft should be replaced.

thank you!! :) would you recommend a junkyard driveshafr? because i really dont have the money to buy a new one... i plan on picking up the driveshaft from the j/y and taking it to get balanced and have the u joints greased before putting it on the truck.

Better to have the junk yard u-joints replaced especially the rear one.

If the front joint moves freely, don't worry about it, but the back one should be replaced no matter what.

definitely, thanks for all the help guys i hope thsi finally cures my vibration problem. i will update :)

well guess what... changed driveshaft to a brand new one and of course vibration is still there!! what now??? i cant believe this is so hard to find, i just want it to ride smooth :( anymore suggestions?

well guess what... changed driveshaft to a brand new one and of course vibration is still there!! what now??? i cant believe this is so hard to find, i just want it to ride smooth :( anymore suggestions?

I agree with LT, you may have a slipped belt or a missing wheel weight on one of your tires.

yea im honestly thinking thats all thats left... i cant think of anything else. if i do get new tires what all do you guys recommend that arent that expensive? i have heard to stay away from goodyear, and i have futuras on there now, so what else isnt bad for a good price? im thinking uniroyals or bridgestones or something along those lines, not too expensive but a good tire. any suggestions would be awesome. oh and another thing thats kinda puzzling, if its a driveline thing would it even be possible for the steering wheel to vibrate from it? cuz when i get up to like between 50-65 the wheel has a real fast vibration, that feels like the sound im hearing from the rear. so that makes me think that maybe its not from the rear at all?? could it really just be bad bearings in the front??? thanks guys!