1996 Plymouth Voyager 140000

Did you replace the half shafts or was it done at a shop? Normally the person doing the work warranties their own labor. Parts prices are marked up to help cover the cost if the parts have to be replaced again.

What kind of half shafts were installed? Remanufactured units are best because all worn parts are replaced. Used ones could have a broken spring inside the inner joint. That would allow the housing to slide out of the transmission. For it to get that bad, you'd be sitting on the side of the road before much damage could occur to the transmission.

Did they find metal shavings by the axle seals or in the transmission pan? If by the seals, I'd wipe them clean and put new half shafts in. If in the pan, why would they be looking in there? That's a lot of work and mess to take the pan off just to look around.

You are going to have to admit, if they did something wrong during the installation, why did the shafts last two and six months? They would have caused problems right away. You didn't bother to list the mileage, but if you needed half shafts, I'm guessing the mileage is well over 150,000 miles. It's WAY more likely you should have needed a new transmission before half shafts. My mother's 1995 Grand Caravan only has 130,000 miles and is on its third transmission. This is common with the computer-controlled four speed that you have. In comparison, my old 1988 has the three speed hydraulically-controlled transmission. I pull an enclosed trailer that's bigger than the van, and have only changed the filter once in its 210,000 miles.

What I'm trying to say is it's more likely metal filings in your transmission are not from the half shafts. Have them put remanufactured shafts in, and drive it. If the transmission gives you trouble later, blame it on the mileage. All manufacturers have cheap designs that do not last the life of the vehicle like they did a couple of decades ago.

You might politely ask for a break on the labor charge, and many shops will try to do something for you to keep you as a customer. On the other hand, I can tell you from my previous career as a tv repairman, some people will complain and be angry at the repairman because their tv broke down. It wasn't our fault, but if we knew someone was going to be crabby no matter what we did, we charged them plenty to get them to call someone else next time. No sense trying to help someone who's going to cause you ulcers.

It can be hard to predict the future too. If they had known something would happen on the way home, they wouldn't have let you leave the shop. After rereading your post, I see the shaft perhaps did not pop out of the transmission. As I read it, you just parked it because it made a noise, not because it wouldn't move. If that's right, you might have nothing more than a defective outer joint. It's extremely rare for an outer joint to break completely to where the vehicle couldn't be driven. I really doubt they did anything wrong when they installed the shafts. They just aren't that complicated or hard to put in. I'd look closer at the source and quality of the shafts

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