My Recent Failed Spicer U-joint (pics)

[88gmctruck]

So, last Friday after classes my truck started making a very weird clicking/metallic sound that I have never heard before. It was very prominent and changed with speed and also load. It also developed a noticeable vibration. So after a quick parking lot drive-by diagnosis, it was determined that it was coming from the rear of the truck. My first thought was the G80 was about to bite the dust (between the original truck it was in and mine it has over 300k). It was suggested by Devin to check the U-joints as well.

So, the next day up on jackstands it went. I had a friend "drive" the truck while I first listened to the rear diff.... no sounds inside there. So I moved forward and listened to the transfercase area. I could hear the sound towards the middle area, and saw the driveline moving out of round. So I checked the U-joints. The rear Precision 447 conversion U-joint was "loose", however the front spicer joint felt fine. After replacing the rear joint, i moved to the front one which seemingly felt good. I'm really glad I looked close, because it was far beyond good.

Only 1 of the 4 shaft/caps had failed. Something must have clogged the grease passage at some point in time, because it obviously had not gotten grease and was burning up. Notice the cracks in the cap, and ground up needle bearings. The only indication from the outward appearance that the joint was failing was the cracks in the caps itself.

Prior to diagnosing the sound, I was 99% sure the U-joints weren't bad, as they were barely over a year old and greased regularly. I literally had inspected and greased them during thanksgiving while the trans was out. I also think the conversion joint started to fail because this one was, as it was properly greased as well, and had VERY little play.

 

[ak diesel driver]

another way to check u joints is after a drive reach under and feel the caps. the bad ones will be hot sometimes really hot ask me how I know.

 

[88gmctruck]

Didn't think of that, but it would have lead me in the right direction as well....and possibly to an ice pack.

 

[trouttrooper]

Well that sucks.

I've found that the "grease" that U joints come with can very easily act like a plug. I've always taken the caps off (carefully of course) and shot grease into the core while still on the bench. Once I even had to use a toothpick to get one side to open up.

 

[88gmctruck]

I actually had that happen while installing the new u-joint, the passage was clogged and had to get the old stuff out with a screwdriver. I've always bench greased them with the caps off first, then put the caps on with a little grease in them so it oozed out.

At least it made itself known, instead of failing while on a trip or driving.

 

[3500GMC]

Yep, clogged up with JUNK grease. The non-geasable versions are a PITA to get lubed good but worth it in the durability department. The only deal breaker is, You gotta use a GOOD grease.

My fav is good old Mobil 1 synthetic.

Photo shows how I do the grease swap. :thumbsup:

 

[88gmctruck]

I'm actually wondering if something contaminated it because we use synthetic grease, it was some really good stuff that dad got from work.

Your greasing process looks simliar to what I did, except I didn't have a vice.

 

[dracor85]

Your lucky, I just had my Ujoint let go yesterday only problem was I was doing 65mph down the highway when mine totally failed. I dont know if its the new Ujoints that are coming out or what because I just put these ones in a year ago and did the same type of pregreasing like you guys did. Fortunatly for me I have a real good driveshaft shop here thats going to put a new tube and end on it and rebalance the whole thing. They laughed when I brought my driveshaft in because it was so small. Some of the stuff they had sitting on the counter was amazingly large, I didnt know that driveshafts were made with 8-10" tubes on them.

 

[Ed HD]

Our 05 has about a 6" diameter driveshaft. It's big.

Good to know guys, I always grease the grease-able joints till it oozes out all 4 caps.

 

[bison]

Pumping grease trought the seals is good way to F up the seals from the start.
I take the caps off and blow that hard grease out with compressed air,then fill the cups and put them on and let the excess depart trough the nipple hole.
But i too found that aftermarket joints don't last as long as the original ones.