driveshaft issues

[muleys67]

Hello, all. My 86 longbed has a vibration at hiway speeds so Im replacing ujoints and carrier bearing.Upon separating the 2 halves of the driveshaft I found a small plastic piece under the nut that separates them was broken into several pieces.This keeps the shafts together supposedly.Where in the world will I find this plastic ring? Its under the thin metal nut on the long shaft.I dont think I can run my truck without it.Suggestions? Thanks, guys I appreciate your help.

[pontgta]

Pics would probably help to out to help .

[Gmc.guy]

Do you mean the threaded sheet metal cap on the end ? I think you might mean the rubber gasket that goes under it? It's a grease seal you could get away with out it might just lose grease and messy, until you find one It doesn't actually hold shafts together you just have to screw it off to separate the shafts

[Gmc.guy]

It just slides with the shaft on the splines

[muleys67]

Thanks for the replies. Yeah this one is toast. Wondered why grease was all around the carrier and body.
So, is this seal available? Upgraded maybe? Now just gotta press the carrier on and Im set.Hope the vibes are gone.I appreciate the help. Muley

[Chevy3+3]

What year is your truck. What t-case are you running? What type of vibration is it? Is it speed related, constant at all speeds or a pulsating vibration that comes & goes?

[muleys67]

Hey, guys, thanks for the response.My truck is an 86 Scottsdale, 4.3 v6 with my6 4 speed trans, or 3speed w/overdrive.The vibration is all the time.Ive recently r&r the u joints, carrier bearing and this helped alot.There is more slack in the ring and pinion than I like so Im leaning to rearend replacement.Bought this truck used, just now beginning to work out the bugs.The po told me another family member used the truck after the original owner passed, so I think it was driven harder, (yeah 4 speed).All the ujoints and bearing helped some just not as much as I wanted.The driveshaft will turn almost a 1/4 turn before engaging the ring. Doesnt roar or grind yet but I feel that is on its way.Im thinking it has a 3:73 gear in it.2 wheel drive. I like this truck so I want to fix it. Oh, by the way I fixed the seal on the driveshaft with a
piece of O ring material.Dont know how long it will last but better than nothing. Thanks again
Muley

[Jaysonb]

My rear end had a bunch of play in it as well. The ring and pinion were fine, I just had to replace the spider gears. Pretty cheap, easy to install, and no more slop.

[Chevy3+3]

My rear end probably has that much play but I don't have any vibration. Have you checked to see if your transmission mount is still in one piece? It might be broke. Sometimes it's hard to tell with weight resting on them.

[barry1982]

I had a similar problem a few years ago, New u-joints/center bearing and had a bad vibration. Talked to an old GM mechanic and he said to check that the balancing weights tacked on the front/rear drive-shafts. He said it's important that both are on the same side. Sure enough, while installing the u joint, I must have rotated the shaft 180 degrees. One drive-shaft had weight toward drivers side, the other toward passenger side. I pressed out the joint, rotated 180 degrees and put back together. That was the ticket.... vibration disappeared.

[TrailerTrash]

Originally Posted by Chevy3+3

My rear end probably has that much play but I don't have any vibration. Have you checked to see if your transmission mount is still in one piece? It might be broke. Sometimes it's hard to tell with weight resting on them.

this is a good suggestion. my 79 K10 had this same issue. the transfer case mounts are different than a 2wd trans mount but they do the same thing. get old and dry rot/fall apart/get smashed flat.

i couldnt figure out what the vibration was and sure enough the rubber was toast.

[muleys67]

Well, I didnt pay attention to the weights on the shaft or the trans mount.Tomorrow is another day so Ill be under the truck again.As Ive said before, the po didnt abuse this truck, someone else in the family did after he passed on.I wanted to r&r the pinion seal while shaft was out but I didnt have the right socket.What size is the nut? So spider gears could be causing the vibes? Havent taken the cover off as the fill plug is seized.May have to heat it to remove. I would have pics but I dont know how to post them from my phone. Guys, yall have been a blessing to me for help.I thank everybody. Muley