cohocoal

I have a question regarding the carrier/support bearing on the drive line. I had a new one installed ( not a mopar) and it blew out after about 500-600 miles. I installed another one, same style but I'm concerned as the one that was replaced was original with 180,000 miles. There doesn't appear to be anything amiss. Is there a difference between the mopar and after market? Is there something I should look for that may be the cause. Do drive lines fail or become unbalanced?
We are towing and a long ways from home.... Any thoughts or suggestions would be appreciated.
Thanks

deere country

If they are installed with a preload applied to the front or back side meaning front or back side of the rubber they would certainly fail prematurely.

cohocoal

I can't say how the last one was installed, but this one was installed such that the tranny end was in, the bearing and mount were installed but only snugged, the differential end secured then the mount was tightened. The tranny end yoke is about 1 inch from the transfer case seal. When the previous one blew it shoved the yoke forward into the seal. That needs replacing now but will not happen for a few days. When driving it feels like there is a minor vibration. This is baffling but I will continue to use the truck but be a bit paranoid till it fails again or I find the source. Probably something simple.
Thanks

cohocoal

As a follow up, I did put some lubricant on the splines of the slip yoke as I can only think that some binding may have loaded the bearing and blew it forward. Time will tell and I will check it as we go.
Thanks

gorms

As for vibration, if you separated the 2 piece driveshaft, the splines are keyed but 180* apart. Meaning they can go back together 2 ways.....the way it was balanced at the factory and 180* apart.

cohocoal

That is most likely the problem. I may also have my rear suspension getting soft. We towed our trailer ( 2 horse with L Q ) down to Az from N W wa. After arriving Az we filled a 55 gallon drum with water. We think that's when the bearing issue arose. Soooooo I'm going to beef that up. We are heading back soon and will leave the drum empty. That may give us a firm conclusion on the rear springs.

KATOOM

The 180* issue is NOT a balancing problem but a "timing" problem. Balancing has nothing to do with the oscillating velocities of the joints.

You have to understand how u-joint drivelines work to best understand what can happen if you improperly install them "out of time". The joints have to be positioned exactly opposite of each other otherwise the opposing oscillation movement will cause conflicting harmonics which will destroy the driveline. Here's a very short video to best explain.

torquefan

Great video! The theory of u-joint phasing has always made sense to me, but the demonstration with the credit card against the wheel illustrates it pretty well.

cohocoal

Excellent video!!! I pulled the shaft and found mine can be assembled one way. One master spline so the assembly is correct. I'm not sure what the cause is but today the vibration was a bit different. I cleaned my the yoke and caps real well and assembled again. Above 60 mph the vibration was back. I drove at 55-57 mph and it was barely discernible. Thinking a u-joint is wearing. I'm pretty sure my suspension is soft and think that may contribute. I'll slide under and check for sloppy u-joints. The new bearing rubber is still firm. We're heading home but I'll keep looking for the cause before it fails.

NJTman

These issues are exact reason why I no longer install my own I joints anymore on my main two piece rear shaft. I went through a bunch of the offshore center bearings, and finally caved in and bought a mopar unit. Brought the shaft, the bearing to the local drive shaft shop where they installed the mopar center bearing unit, New Spicer non greasable joints, assembled and most importantly balanced the unit. Not one issue since.

The mopar units are made to spec, while the offshore units are not. I think I paid a little over 100 for the bearing. Couple hundred including new Spicer units for everything. Not a single peep since.

Don't forget that There is a tsb regarding the center bearings needing to be dropped down 1/2" on early 1st gen club cab models....

KATOOM

I've preached for years that even though changing u-joints "can" be simple if you've done them many times, it can also be a pain in the buns. If you're not careful you can easily do more damage by smashing needles, dropping/loosing needles, crushing caps, bending yoke ears, getting them too tight, etc...

Most driveline shops hardly charge anything over the cost of the joint to install and balance. Why go through the effort and time to fart around with them yourself??? I stopped messing with them forever ago too.

cohocoal

Over the last several days I've been rolling towards home. I've checked the u-joints then greased them. I'm fairly certain I have one that is failing. I greased them in mid January so figured that was not the issue. I'll change all 3 at home. Then see how that works. After greasing the vibration was noticeably better. Easy enough to slide under and shoot some grease into the joints. Keep it under 60 and it's running well.

cohocoal

We got back but experienced a gawdoffall shaking up front. Death Wobble, but that's on another thread. I did the test on the u joints again. They seem fine but I did see a piece missing (small) on the yoke of the tube at the rear. Looks like I'm going to a drive line shop. Not sure that's the issue but will have them repair it.