Uni joint let go. Badly.

[doc]

Well, it's one you dont experience very often, but I had the rearmost uni joint fail on me the other week. Pulled the tailshaft out, slipped her into 4wd and drove home on front wheel drive.

Weird situation...

I changed the uni's a while ago - probably 2 years or thereabouts??? I haven't done a heap of miles since then, but certainly enough to show up an endemic problem I would have thought.

What seems to have happened is that one of the retaining clips has worked its way out of its groove and gone walkabout. Very quickly afterwards, the now free cap worked its way out and ran away, with the tailshaft now able to work it's way free. Thankfully it was retained by the cross member behind the TFR case, long enough for me to idle off the side of the road to work out what all the racket was about...

So. Next time you're under your ute doing something, might be worth checking the uni retainer clips are properly seated. Just in case...

 

[Old.Tony]

Aren't those clips only removable with those circlip pliers, and they're in a recess so they can't snag on things?

Glad the cross-member's there. Have heard some horror stories about drive shafts digging into pavement!

 

[Tappet]

Thanks for the tip.

Interestingly had a friend of mine with a Spanish 09 D40 replace the replace his recently.

 

[nathand22]

When you changed uni joints were you 100% certain ALL of the little pins inside the cap were still there when you pressed them back together? I know if even 1 of those fall out it can cause them to fail so badly the entire thing disintegrates.
the other reason they may fail is if they were binding up at all, when you finished the install were the uni moving freely?
sometimes when you are pressing out the old ones you can squash the actual "saddle" or "cup" slightly causing the joint to bind slightly which allows them to heat up and then fail.

 

[Navmania]

Yeah, the diff end is bad but if the gearbox end hits the ground it can poll vault you on your lid real quick. That's with a one piece shaft anyway. The center bearing in the Nav may help stop that from happening but still wouldn't want it to happen.

 

[doc]

Hey Nathan, thanks for the concern mate. A detailed knowledge of a subject is always welcome so cheers for that. Yep, all the needle rollers were there - I check and double check when installing the new caps. Am a mechanic by trade and have been stung before. *insert embarrassed look here*

Tony - the clips on most replacement unis are just a simple flat clip - needle nose pliers being the best tool. That's the majority now anyway. Reason being, they are easier to seat properly than a large circlip.

All I can think is that I stuffed up - that I didn't locate one of the clips properly (all other 3 were perfect when I checked the failed joint in the diff-end yoke), and it's just worked its way out over time.

As it was the rear joint, the shaft dropped and hung up on the cross member (single piece tailshaft in the D40's). Thankfully (!!!!!!) the shaft didn't drop out of the gearbox and deposit itself on the road. Yuk. Also thankfully, it was the rear joint, not the front one. As soon as I heard that noise, I knocked the box into neutral and clutch in. That stopped the tailshaft rotating. If the front join was the one that failed, it would have kept being dragged by the diff, and would have flogged itself to death on the underbody of the car. And damaged who knows what....

Tony - these are the clips I'm talking about (pic stolen from someone else):

 

[nathand22]

Maybe there was a tiny little peice of crap in the groove which stopped it from seating correctly