I wonder if low-quality bearings could be the culprit. As far as I know, just about every bearing manufacturer has closed up shop in the US and now imports from the far east. Japanese bearings used to be top-notch as well, but I think that they have even outsourced to cheap-labor countries.

One of my side hobbies is rebuilding vacuum cleaners, and I typically go directly to the bearing distributors to buy replacement bearings for motors and brush rollers. The quality of the bearings that I have purchased has gone down dramatically over the past 7-10 years, and this is confirmed by my conversations with a number of vacuum cleaner repair shops. Bearings now are lasting only 20-30% as long as the "good" ones used to. This isn't so much of a concern for consumer-duty use, but for commercial use, it's a big problem (with no solution in sight that I can see).

Towing will definitely put more stress on all of the driveline components, so it's possible that this additional stress is enough to cause failure of the bearing (due to insufficient or improper lubricant type, or improper metalurgy or hardening). Just one possibility.

 

redmondjp brings up a good point as to quality of the bearings !
also might be the quality of or lack of grease that the CHINESE put in them !

 

Had not thought of that. I will ask the driveline shop, I think I will be visiting them again. Another post yielded a suggestion to check th driveshaft. There mabe an issue with it that is exaggerated when towing, maybe a slight bow or something. Thanks for your thoughts guys.

 

I would:
1.- Buy Timken bearings.
2.- Pack them with synthetic grease before intallation.
3.- Have the balance of the driveshaft checked.

 

have replaced a few of those if when you seperrate the splined part of shaft to replace bearing or just came apart during trannie r&r the u joint have to be opositly oriented or can cause vibration and bearing failure

 

I just went through the same thing, on my 3rd torn up carrier bearing in less then 100 miles, I had les schwab do all the work, they finally found the issue, the cross member that mounts the bearing is bent about 3 inches, so, instead of dropping the gas tank and going through all that to replace the cross member, I am just going to find a solid 1 piece drive shaft to replace the 2 piece. Any one see any issues with this other then the shaft will sit a little low in the center of it?

 

just make sure there is a slip joint in there that has enough movement !

 

Index the drive shafts when you put them back on

 

So what prevents the piece of the shaft that slides into the tranny from sliding out if i get a 1 piece straight drive shaft? Was thinking about that yesterday.

 

you will need to figure out how much drop the rear axle is going to have before the shaft comes out , and then you might need to use some limiting straps !

now the other side to this what will keep the shaft from bottoming out in the tranny , over loaded , to much compression from say jumping , you will also need to figure that out and then put some bump stops on that will prevent the shaft from bottoming out in the tranny , if it does bottom out it will destroy the tranny !

 

I had to read that a couple times to understand lol. Yea I dont plan on jumping this rig.. at most I might go offroad to go camping, but I baby this thing.. But I will definately look into both mods for sure.
I cant remember off hand, and at work, do the drive shafts expand naturally or does it free play if its disconnected?

Oh and I jsut thought of this, You guys might be thinking I am trying to go to a solid shaft.. All I am doing is getting a normal straight drive shaft out of another rig to bypass the need for a carrier bearing. It will still technically be a 2 piece shaft that has the ability to compress and decompress. I am just getting rid of that stock shaft that has the carrier bearing and knuckle thing in the middle of it.

 

correct me if im wrong but to do a one piece drive shaft wouldnt you have to put a slip yoke in the transfer case......still sounds like your throwing the carrier bearings due to the fact your not indexing the drive shaft when you put it back on

 

I don't know, les schwab did it all, I might try to do it myself and see if it fixes it

 

Driveshaft carrier bearings are pushed out of the rubber in the "hanger" by one thing. The splines of the slip yoke in the middle of the driveshaft are binding. When the splines are bound up, the driveshaft is effectively turned into a one piece driveshaft. Then the suspension compresses pushing the driveshaft (as a whole) toward the transfer case or transmission. The "hanger" is bolted to the frame/cross member so it can't move, and the bearing is pressed onto the driveshaft which is now moving as one big piece, so the bearing pushes out of the rubber.

 

Ive eaten thru two carriers same way in two days. Do u think over tightening the "hanger" bolts would cause this?

QUOTE=Kevin Roth;12688032]Driveshaft carrier bearings are pushed out of the rubber in the "hanger" by one thing. The splines of the slip yoke in the middle of the driveshaft are binding. When the splines are bound up, the driveshaft is effectively turned into a one piece driveshaft. Then the suspension compresses pushing the driveshaft (as a whole) toward the transfer case or transmission. The "hanger" is bolted to the frame/cross member so it can't move, and the bearing is pressed onto the driveshaft which is now moving as one big piece, so the bearing pushes out of the rubber.[/QUOTE]