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I’d just done all 3 of my u joints on my 2 piece drive shaft on my 1990 f-150 4.9l manual trans rwd
immediately noticed vibrations that got worse. Made it about two miles before my drive shaft fell out of the rear yoke.. photos attached.
my dummy self forgot to take photos of the removal but everything seemed correct. My question is did I just not torque down those loops that hold those caps in enough? You can see in the photo one is still there, but somewhere the other one popped out and let the ujoint slip out.
I’ve been having trouble finding a diagram for this exact driveshaft setup
Snugged down with a wrench should be tight enough to not come apart. Did you mark the alignment of the two driveshaft halves to make sure they stayed in phase for reassembly?
Snugged down with a wrench should be tight enough to not come apart. Did you mark the alignment of the two driveshaft halves to make sure they stayed in phase for reassembly?
I marked it but now second guessing myself on tightening it enough, it was a cold day so my dumb a** might’ve thought I tightened them up but didn’t. Is that how This setup works? You just tighten down those loops that hold the caps in place? There aren’t any clips or anything right?
As My4 just said, tightening equally is important. Just like when drawing down lug nuts. Simple but crucial. Those loops are a fairly close tolerance to where they go thru the holes in the yoke. If you draw down on one side of one of them, it can bind a bit so that when you tighten the other side of the loop you reach enough torque, but the loop is not tight on the cap. And if laying on your back using a flashlight, it may go unnoticed.
You may have used the wrong u joint with smaller caps like the other 3?
The rear u joint, if it has a U bolt style yoke, needs a U joint with 2 different sized caps
The 2 caps that are under the U bolt are slightly bigger diameter than the others
You may have used the wrong u joint with smaller caps like the other 3?
The rear u joint, if it has a U bolt style yoke, needs a U joint with 2 different sized caps
The 2 caps that are under the U bolt are slightly bigger diameter than the others
It does? That’s news to me. Mine uses u-joints with all the same size caps.
Looks like the orginal u bolt on there, but I’ll throw this out there for you just in case.
If using new u bolts, I ran into an issue a few yrs ago, the new u bolts had the wrong length shaft, the shoulder would contact the yoke before tightening on the caps. Part number matched correctly.
It is possible your originals were stretched as well, or simply loosened off. When you reassemble, use a little low/medium strength (usually blue) Locktite. Make sure your lock washers are still locking washer as well, not flattened out. I have found them loose / finger tight in the past. Recheck the rest, you don’t want the front dropping..
There should also be a tab on the yoke, strap, or ubolt on there to hold the cap in place from being thrown outward with centrifugal force.
Pics for reference of new ubolt shank too short. You can see the gap on the cap of the u joint.
It does? That’s news to me. Mine uses u-joints with all the same size caps.
when I swapped the rear end from a 1990 into my 95, it had the strap style not the flange style. And yes I had to get the smaller u-joint caps to make it work. I figured I could just pop the newish joint out of the companion flange and use it, but the caps were a fuzz too big. And come to find out, nothing about the joint itself is smaller. The cap walls are just thinner. I know that because instead of knocking the 1500 mile joint out of the driveshaft I just swapped caps.
