When I take off in second gear there is a shutter in my truck. It feels like it is in the drive train. It also makes like a noise almost like a pieogeon cooing. I have no idea mabey rear u joint? My truck was doing this before I put the DD in and now with the extra torque transfer it seems to be getting worse.

 

Mine is going to. I can feel it when I tow. I searched on here. It seems to be pretty common

 

get under truck and see if you can wiggle drive shaft... it could be the u joint or the carrier bearing...

 

^ That trick never worked for me. When we've changed out u-joints we usually just have to take the old one out and check all the pins. Some of them (bad enough) will freeze up and stay tight til you get it loose. That whining though seems a little more oriented to the carrier. If you're looking at pretty decent mileage, I'd go ahead and change them anyways.

 

Sorry I haven't replied sooner. I crawled under neeth the truck the drive shaft feels fine ,but I can wiggle the whole trans and t-case around. I can get about a whole inch of movement out of the trans mount. How much is normal? and I don't have a carrier bearing.

 

I agree with rip here, unless the joint has ground the needles you might not find any slack.

My Son is a Parts Manager and other Son is a mechanic. When I bought my truck they both said I should stock an extra rear driveshaft U-joint because these trucks eat them. I'm not sure why. I bought my truck with 62K miles on it and the pinion U-joint was out.

An indicator for my mechanic Son is a customer complaint of vibration. He's a driveline/alignment guy and sometimes spots a bad joint before the customer even complains about it. When they choose to ignore him he then gets to do a replacement later when they are back with the vibration complaint. Sometimes that results in driveshaft or yoke replacement when it explodes.

His visual is to look for a slight rusty dust around the cap seals. When the joint gets dry and starts grinding the needles it will spit out this dust. Even the slightest amount of dust is your warning for pending doom.

Edit: Oh wanted to add a comment to Beaver's remarks about a shudder on takeoff. That's common for a failing driveline. The most torque is applied on takeoff, especially for a modified truck and throttle happy driver. I'll quote the old TV show "Lost in Space", "DANGER WILL ROBINSON"!!!! Your driveline is giving you ample warning that it's going to fail shortly.

 

Tanks OVRSZD that helped me allot and makes sense what you said. When I take off in second it almost feels like my rear end or trans is going to fall out. Like I said the tuck did this before the DD now I think the DD has amplified the problem. Time to swap out u-joints. Thanks again.

 

Ok where is the best place to buy a good quality u-joint. Any brand names to look for?

 

I have had to replace my rear ujoints twice. Neither time could I move the drive shaft. The clue for me was the grease line on the underside of the truck in line with the ujoint. The first replacement was under warranty and I had to take it in twice as they tried telling me it was due to the angle of the driveline while unloaded. Took it back and showed them the grease line and they replaced the drive shaft.

The second time I was towing at about 19,000 lbs gross and accelerated quickly. I thought the truck was going to come apart. I went to NAPA the next morning and got greasable ujoints and replaced two of the three. One of the joints was nothing but powdered metal in the cups yet I could not wiggle the driveshaft. I got about 32,000 miles out of the sealed ujoints for each set for a total of about 64,00 miles.

 

Had to have mine replaced under powertrain warranty (7/70K). Apparently it's a common occurrence.

 

I crawled under my truck yesterday and looked at my u-joints. It looks like they are covered with powdered graphite. And there is some on the driveshaft to. I guess its off to NAPA to get some parts.

Any tips on removal and installation. I have access to a press if need be.

 

I would get sealed non-geaseable. I have been told that they are stronger because they do not have the passage ways for the grease inside. They are solid thus being stronger... JMO