Thanks 02SPORT,

I still haven't figured this problem out. U joints are tight, and no matter how hard I push or pull on anything there is no play. There IS what seems to be excessive play if I grab the driveshaft and move it back and forth, the way it would move under power. I am going to drop the shaft and hand turn the rear differential, and see if it's the pinion bearing. I have spent hours researching this, and can't find any videos, or posts that describe what's going on. I sounds just like a bad wheel bearing. That's what is leading me to think its a bearing somewhere.

By the way, over 30 mph it roars on and off the throttle.

 

Carrier bearing

 

Isn't a carrier bearing only on 2 piece driveshafts? This is a solid, one piece shaft.

 

Yes, didn't realize yours was a one piece

 

Update

The roar/squeal is coming from from the transmission. Still sounds just like a bad or dry bearing. Seems to happen the worst when I hit overdrive. Turn O/D off, and sound is drastically reduced. Done some digging, can't really find any body else that has had this. Any ideas? Could it just be in need of a fluid change? To be honest, out of all the work I have done to this truck, I have never changed the tranny fluid on it. And, has never been changed (I know because it was grandfather's truck before I bought it from him). Has 105k miles on it. The truck is bone stock other than an intake, and has not been "hot rodded" or abused. Tows and hauls a little here and there, nothing super major.

 

Fluid change couldn't hurt. You indicated the fluid hasn't been changed in an unknown amount of time. When was the last time you checked the level? A half-full torque converter will make noises like a roar as the fluid and air cavitate inside it, especially when you let off the accelerator or lower the RPM's by turning on O/D. As the tranny pump slows, the converter empties. Hope you're not looking at a rebuild!

BTW, you and JBearSVT described some questionable diagnosis actions. Yours, jacking the rear end up and running the drivetrain to 40 MPH, was nowhere near as dangerous and his, "so I rolled across the parking lot hanging out of the truck looking underneath". WOW! Made me laugh and cringe at the same time! I can't believe you guys haven't visited your local ER's! Careful fella's!

 

I have had the truck for about 5 years. It is a 99. The fluid has never been changed. Fluid level is fine. It doesn't smell burnt, or or look discolored. I am taking it to the trusted tranny shop on Monday and see what they diagnose it as.

I had the truck on jack stands and the front wheels chocked when I ran it to 40....still got a little white knuckled doing it though!


Thanks for your reply!

 

I guess compared to hanging off my supersport down the highway in traffic at 75mph+, hanging out of my truck at 5mph in a wide open, private parking lot just doesn't seem all that dangerous.

 

UPDATE:

Had to get a full tranny rebuild. A c-clip in the O/D tail let loose and fed it's way through the rest of the transmission, destroying everything. At first it was just the overdrive acting up. I took it to the shop and test drove it with the owner of the shop, and we lost 3rd, then the tranny went into neutral. Had to shut off and re-start several times to get back to the shop! Got an upgraded torque converter and all new guts, runs like a champ now!