Hey Fellas, Im in need of some help here again.
Yesterday I had the u joint that connects the rear driveshaft to the diff break off while I was driving. I wasnt going very fast, maybe 30 or less.

The driveshaft front stayed in place but the rear came down on the road. It actually doesnt look very damaged, except for some grinding/scratching on the end where the u joint sits. However the pinion shaft yoke/flange where the u joint connects to the diff got beat up. One of the bolts was sheared off, both of the straps (for the u joint) are gone and the inside of the yolk, where the u joint actually sits has a couple of gouges in it.

I spent a bit of time researching on here, and it doesnt seem like to hard of a repair. I will obviously need to replace the u joint. I think attempting to repair the damaged yolk is a terrible idea, so I am lookiing into replacing that also. I havent taken a pic to post yet, but the yolk on my truck has a 'disc' like feature below it, kind of looks like a giant washer. Guy at the parts store (autozone) told me that means my rear diff is a '30'. In which case the replacement part is like $240 !! vs. $40 if I had the '44' axle.

That brings me to the only logical solution; go to the pull and pay. Unfortunately for me the closest one is a 2 hour drive each way ! Still better to pay $11 instead of 240.
I know someone will groan but I am not planning on replacing the pinion seal when I change the yolk. At this point I am hoping to just replace the yolk, straps and u joint.
While researching similar problems on here I noticed that several people (as well as the manual) recommend using a inch's per pound torque wrench during the process. Will I need to acquire one of those or will it not be necessary since Im not planning on messing with the seal ?

I am also wondering what other special tools I might need to get that yolk swapped out. Especially since the pull and pay doesnt rent or loan tools, they all must be brought. Will I need a gear puller to get that thing off ? What about a tool to hold the flange while I break the bolt free ? Would a pry bar work ?

I have done u joints before (on the front axles) its not fun, but I am familiar with the rental tool required to get it done, so Im not too worried about that.

Should I have any concerns with the driveshaft ? The pull n pay sells them for $20, but I d rather not replace it if it doesnt need to be.
Is there anything else I am forgetting or need to be considering ?

 

Additional backstory;
I had noticed a few months back, when I would first pull out of my parking spot in the morning that as I turned and accelerated I would notice it seemed like the front of the truck was sort of jolting or slipping around the turn, this was accompanied by a clunking/grinding sound. Even while accelerating in a straight line it would make a ruckus off the line.
I started researching it and wondered if the rear diff was going out. I jacked up each side of the rear of the truck separately and attempted to turn the rear wheels (with the opposite tire on the ground) I noticed that I could turn each tire and also could hear a horrible grinding sound. I crawled under and checked out a few things and everything else looked ok. I did not properly check that joint. I gave it a pull and it seemed ok, but I should have noticed that it was barely hanging together. I presumed that I would need a new rear diff and proceeded to research finding one or a donor truck. So when this happened I was actually sort of pleasantly surprised. I figured a u joint isnt as bad as swapping a entire rear end. But with the yolk replacement being added to the equation, Its gonna be a pretty big chore.

 

Without a picture of the yolk I can't help. Never heard of different rear ends in this trucks. A Chrysler 9.25 is just that. To get the yolk off you'll need a prybar, impact gun, and more then likely a hammer

 

Thank You. I will grab a quick pic of the yolk and also the driveshaft, just for assessment by the pros on here. I will post back later today.

 

How necessary is the impact gun ?

 

Just about absolutely. The pinion nut is on there pretty tight, and getting it to break loose is an exercise. You *might* be able to do it with a breaker bar, but, it won't be any fun.

The seal is only a few bucks. Replace it. Otherwise, you will likely get to do this job again.

The inch-pound torque wrench is for testing rotational torque required to turn the pinion. Test this BEFORE you take it apart. See how much torque it takes to turn the pinion. When you put it back together, set the torque to 1 or 2 pounds tighter.

Replace the driveshaft. It was flopping around under there at pretty high velocity, it's likely bent.

You have a corporate 9.25 rear diff. If you can find the correct yoke in the junkyard, go for it. All of them (new) I am finding are at least 160 bucks......

 

I never knew you were suppose to do that. I just tightened the not down as hard as I could

 

Thanks for the help everyone ! I knew Hey You would be in here. Helped me a couple of years back when I tore the gears out of the front diff ! So I got back under there and got a few pics for yall.

a longer shot of the entire section of drive shaft with the broken U joint in the foreground

The area of the drive shaft that received damage and the broken u joint.

The Yoke. The bolt at the top is the one hat got sheared off. I do have one strap still but its battered.

 

After Looking at these pics closer (inside where its warm !) I am considering not replacing the yoke. If I can find replacement straps (online presumably) I would only need to replace the u joint, those bolts and of course drill and tap or helicoil where the broken bolt is. I hate doing that. Its such a PIA drilling bolts out, extractors rarely work well since its tough to get them deep enough into hard bolts. Question is would I spend more time making the 2 hour drive each way to the pull and pay to get the yolk, not including the time it would take to find and remove the actual part, also not including the time it would take to remove the yoke from my current truck...or would it be faster to spend the time drilling out the bolt and tapping in a helicoil / new threads ? It seems even in best case scenario it would probably take me at least an hour to pull each yolk, and thats if things went smooth, and also considering I dont have an Impact wrench I would be using the handle from my floor jack slid over a breaker bar. Done this before on other bolts. Not fun but it does usually work. Adding that time to the driving time brings my time to at least 6 hours and thats not including the time to change the u joint yet either. I could probably drill that out faster than 6 hours, even though I dont think power cords could reach it. I would need to use a cordless. Its definitely something to consider. Not Ideal, but I could just drill out, tap threads, replace the straps, bolts and u joint, put it back together and be driving. If there is vibration I could always decide to replace the shaft at that point. The weather here is not very conducive to wrenching in the parking lot at the moment. Its freezing cold, single digits with wind and snow on and off. When things clear out a bit I will be giving it a try. I will post when I have tried drilling the bolt out. FML !

 

Replace the yoke. That was in blown out on the thrust side on that one end. That will put a lot of stress at an odd angle on that part of the u-joint, and you will likely experience premature failure.

That guy had to be bad for quite some time to tear out like that. I am surprised it didn't make any rude noises, or give you a nasty vibration.....

You could prolly try the original driveshaft, if you have a vibration that you just can't seem to find, then considering doing something with it.