Vibration-Then Roaring Vibration

[Rob]

ok, after i took the rear shaft out, i cleaned it up real good. greased my slip spline, got that all together. started feeling the Ujoints. they all feel real good. i have no play, and everything seems to rotate or move with out any real force. should i go ahead and change them anyway? or should i look into messing with my pinion angles? i still have to do the front half of the rear shaft, maybe tomorrow. it looks as if i have to remove the carrier bearing along with the front half??? never done that either. anyway. thanks for the help. ill let you know what happens.

[ssquire37]

"should i go ahead and change them anyway"

I can not say to R&R but I will tell you to look real close between the cap that is pressed in and the actual steel "T" body of the ujoint. There is a little rubber bushing that holds all the needle bearings in and in place, if those are bad I would change the ujoints. 2 of my caps rubbers were completely ripped apart and those were the 2 with no needle bearings. This was my first time doing ujoints hence probably why I trashed one of the ujoints by droping all the needle bearings on the ground.

Shane

[Rob]

hmmmm, i did look at the rubber seals, or caps, or whatever they are called. there was no cracks or splits. there was one side that was a little harder to turn than the others, but i dont really think it would matter with all the torque on the shaft while driving. maybe ill try replacing the rear ujoint, since that was the one with the stiff bearing.

[ssquire37]

Rwalker I just noticed in your sig you have a lift. Mine is not lifted (stock). There is another thread in this forum started within the last week talking about spacers on the carrier bearing you might want to check that thread. I read all the replys on that thread and they complain about roaring vibration also. So what the drive line shop told you might be correct for your situation.

Shane

[Rob]

ok, i just dont want to have to pay someone over 300 bucks to fix something i can do myself. thanks for the help, even though your issue mimics mine to the "T" . ill post again when i figure this out.

[bill chasser]

Okay I been reading all your threads and there has been a couple day lapse but I'll chime in here. If you have the shaft out change all the joints whether you think they need it or not. you Don't seem to know one way or the other. There should never be any binding when you swivel a u joint in its trunion so you have at leat one thats bad. Second unless you are stuck deep inthe woods with no tools never use a hammer on a u joint especially new ones. Not having a vise available invest in a good steel C-clamp with preferably a flat shaped top on the scew that you can put a large crescent wrench on for leverage, you will need it if the old joints are rusted into the trunions. Open the C-clamp up to acommodate and socket slightly smaller than the cups to press the nearside in while using a deepwall large enough to accomodate the cup on the farside pushing out. But first remove any zirks. I say never use a hammer for several reasons. Safety first as you would be attepting to strike to harden surfaces together and could cause chips to explode from either tools striking you in the eyes, you only have one pair! Wear glasses and gloves if you insist on being stupid. You also face deflecting a blow causing damage to the trunion itself causing a bigger headache in time and labor dressing up your mess to reinstall any new parts. And thirdly you risk damaging your new joints should you misinstall and your bearings in the cup layover or you manage to misalign everything causing again a need to dress your mees and needing to hitch a ride to the parts store for another ujoint. Before you think about it never put old bearings into a new cap to fix your boo boos as you can expect another premature failure. I personally prefer spending good money on better parts even if it costs more money. I recommend using Spicer, Dana or Eaton parts. Also if you are one to go blazing around that little hole for the zirk is a source for weakness no matter how subtle it may seem. Its not just less expensive (read labor intensive) for the oems to use these zirkless joints. With the better greases and seals used today verses even 20 years ago it isnt necessary to be under the truck every oil change chasing down zirks to pee in. Have you noticed how few zirks are on moving steering and suspension parts nowadays?

Unfortunately lifting causes all sorts of havoc with drivetrain that the original engrs didn't design for, ie the need for modified pinion angles. After you finish playing with your driveline and before you put it in, check to see if your pinion seal is leaking. Grab the pinion yolk and see if you can move the pinion up and down, in and out of the differential carrier. Any motion that you can detect is too much and may be the beginnings of a pinion bearing or/and a R&P failure. Drain your diff oil and look for alot of metal particles, or worse,shavings broken pieces/parts. Shine a light into the oil (hopefully you have used a clean drain pan, coffee can etc). If the reflection from the specs is light and scattered then you shouldn't have any worries if there are alot of miles on the oil(ideally there should be none) but, if you see more sparkles than that a lowriders paintjob your looking at a teardown. When/if you decide to service the diff's (oilchange) and you hotrod, tow, do anything hard on a regular basis and don't have posi's, add a eighth to a quarter can of STP to them. This will help to prevent metal on metal contact on all moving parts helping them to run cooler and last longer by preventing the hardfacing from wearing off bearings and gears. Do not use this in posi's as it will prevent the clutches from grabbing within these units. Open diffs, lockers and spools only!!!

Hope this helps...Bill

[Rob]

Bill, thanks for the info bud. i will definately look into changing my u-joints. im gonna tear it apart again this weekend since i have plenty of time. ill look into getting some dnan or spicer ujoints. would you recommend the ones with zirks or without?? it doesnt matter to me if i have to grease them or if i have sealed joints, i like the maintenance i have to do so it isnt a bother.

[lonzo73]

Check your u joints. if you dont know how to do it, put your truck in drive while its off (not running) have somebody hold the brake and get under the truck and grab the drive shaft. Try twisting it and if it has play in it, then you u joints are bad. If you have a two piece drive shaft, your center carrier bearing is prob bad too. You can check that by just pushing on the drive shaft side to side and if it moves more than a quarter inch, then you need to get that replaced too. I just did all that on my truck. cost me about 400 bucks to have it done by a shop. You may also want to get the drive shaft balanced after you put on the new u joints

[Rob]

cant really move the carrier bearing that much. it feels good, but i am going to take it all back apart and check it off the truck. ill go ahead and do the U-Joints, they are relatively inexpensive and easy enough to do. so hopefully that is the issue.

[bill chasser]

Originally Posted by Rwalker

Bill, thanks for the info bud. i will definately look into changing my u-joints. im gonna tear it apart again this weekend since i have plenty of time. ill look into getting some dnan or spicer ujoints. would you recommend the ones with zirks or without?? it doesnt matter to me if i have to grease them or if i have sealed joints, i like the maintenance i have to do so it isnt a bother.

Buyers choice on the joints then.

CAUTION If when you had the driveline out the other day/week and you didn't separate the the slip yoke from the two shafts, be sure to scribe a mark on the slip yoke and the corresponding spline on the other shaft. The two shafts must be properly "timed" or you can/will have a bad vibration from an inbalance and inproper driveshaft phasing. This will destroy the u joints, carrier bearing, pinion bearings, transmission out put bearings etc if left uncorrected.. It will be a miserable thing to drive if way out of time. It is very important that a slot recieves its original spline so take the time to do this right the first time, before you separate the two. I dont remember if you mentioned the mileage or if you know when anything has been replaced but I would change the carrier hanger if you can move it up and down in the rubber bushing. I am of the mindset that if I have it apart now, I dont want to get back into it in the not to recent future when I dont have to. Also check the splines for wear. see if you can feel any appreciable wobble between the slip joint and splines. If you have doubts about what you feel then take it to a shop for confirmation. All of these are fairly easy projects with a few basic tools. And remember always safety first. set your brakes and choke the wheels, Safety glasses...yeah I know nag nag nag but I lost partial vision in one eye for ignoring the same warnings when I thought I knew it all. By the way, I still don't know it all and the minute I think I do and get complacent, that is when a trajedy will happen. So please....