I have the shakes and need some help

[bumpsburb]

Well, I don’t but my 87 burb does. In the last 6 months the carrier bearing has gone bad three times. When I get up to highway speeds the vibration is loud and comes from behind the front seat. I can place my hand on the rear floor and feel the vibrations. Not to mention the loud noise coming from the back of the burb. Any ideas as to what is wrong? It has been in the shop for a week and at first they said the rear end was bad but when I asked why the carrier bearing is going bad they couldn't answer that. Tomorrow they are going to place some sort of indicator on it to see what is out of round. Any ideas or suggestions are appreciated.

Thanks in advance.

[MylilBowTie]

Are you talking about the carrier bearing for the two piece driveshaft or the differential (rear end)? I assume you mean the driveshaft. Has the driveshaft half's been balanced? Has the shop looked at the transmission at all?

[87 STEPPER]

If i were you id'e get your truck out of that shop and take it to a driveline shop look in your yellow pages for one in your area.

They will take it for a test drive and go from there some of the good shops have a dyno type roller drum that they run on for this.

What ever you do get your truck away from that other idiot

[DBLSPRT68]

I was going to say has it been balanced also? I had my carrier bearing replaced, and they said the part that slides(in the middle of the two driveshafts) was rusted solid. I had all that replaced with the u-joints, put them on my truck and had a vibration at about 45 mph. The only problem is that I was just about to go on a 1000 mile round trip. I had to make that trip with it vibrating at 45 mph every time. You don't relize how much your at 45mph till this happens. I took it back when I got back in town, dude says he forgot to tell me it needed to be balanced when replacing a part. Once all that was done, it drives real nice now. You could put the rear end on jack stands and run it in drive with the tires on. I've done that before too. David

[bumpsburb]

I bought the truck in December and had the transmission rebuilt in January. When I purchased the truck it had a howel and after looking it over I noticed the carrier bearing was wobbily. When the transmission was out tehy replaced the bearing and abuot 3 months later ot was making the same noise and the bearing was loose as a goose.

What causes a driveshaft to need to be balanced? I know that it means that it is out of balance, but what causes that to happen?

Thanks again

[87 STEPPER]

A drive shaft has small square's of metal spot welded to it and some times they will rot or be knocked off thus throwing it out of balance.

Also when ever a drive shaft is removed for maintenance it should be clocked or index or phased what ever you want to call it!

So when it's reinstalled it's put back in it's correct position.

[66+81]

U-joint maybe?