I have had more Chrysler minivans that I care to admit over the last 30 or so years. Only one was a shorty - and '89 Dodge Caravan. The rest have been “Grand” - Caravan or Voyager or Town and Country Chryslers. I don’t remember the problem I’m going to attempt to explain on the '89 - but that is not to say it didn’t occur. The rear tires wear with a scalloped pattern around the edges. (I presume it is both edges - I haven’t crawled under the current vehicle - a 2013 Town and Country) A side view would be that the outer rib would show the leading edge of each segment of tread to be higher as is the outer edge. A tire shop that examined one of the vans concluded that because these vehicle are built with 6-7 passengers in mind and many of the miles we drive are with just 1 or 2 occupants, that the rear end is too light. I’ve changed shocks and the issue persists. It gets pronounced enough that a tire shop declined to do the regular rotation citing the condition of the rear tires. Suggestions to resolve this wear pattern will be appreciated.
You need to take it to a shop that specializes in alignment work. Something is wrong in the rear suspension. Do leave the tires where they are as just looking at them gives experienced people clues …
Rotate the tires more often and follow @cigroller’s suggestion.
I suspect the rear toe angle is out of spec
1st thing you need to have the alignment checked, they have shim kits for the rear…
Jack up the rear end and spin the rear wheels making sure the hub flange or wheel is not bent…
I think it calls for 36 psi in all the tires, with NO weight in the rear, you might try to lower the rear air pressure to 32psi and test drive it to make sure it doesn’t effect the driving and keep an eye on the wear pattern, tire may have to much air pressure causing it to bounce due to not enough weight over them… If it doesn’t change or gets worse, bump the pressure up to 40psi and test drive to feel how it is doing…
When rotating, I would either cross X rotate the tires, or cross the rears to the front and bring the fronts straight back…
EDIT: can you post some pictures of the tread wear??
Haha, Mustangman and Cig type faster than me…
This same phenomena has occurred on at least half a dozen of these minivans and they have had 4-wheel alignments.
Just because it had had a 4 wheel alignment doesn’t mean it is correct. Even if it is IN spec, doesn’t mean it is correct.
I’ve had three and never any problems like that. So one of two things - make sure that your alignment shop is a locally owned place with a good reputation, and not a national chain. When it gets aligned, they have a spec sheet that they can print. Ask them for a copy, and for someone to go over it all with you.
Second, do you keep an eye on your tire pressures and rotate and stuff like that? And if rotated, it’s a FWD so the pattern should always be a “forward cross” (though check what the owner’s manual says)
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I am on my 6th Chrysler minivan ( One Plymouth, 2 Chrysler, 3 Dodge), never had trouble with uneven tire wear. I run them with 2 passengers, 6 passengers, seats down loaded with bricks, mulch or building materials (I treat it as a 1/4+ ton covered pick up) and any other configuration you can think of. I did make several runs of less than 5 miles with 900 lbs of wood flooring. I keep an eye on the pressure and rotate the tires. I get my tires from Costco/Sams and they rotate and warrant the tires. So far have not had to cash in on the warranty.
Or throw some sand bags in the back. Tire quality issue?
Some years ago I got a scalloped tire in the rear of my Buick with less than 30k miles. The tire shop put a shim kit in that one wheel. Said often the parts got bent in transit with the placement of the straps. Don’t know but it worked and never had the problem again.
I’m afraid I pass the on all of those points. Locally owned shop that records and keeps spec sheets. I used to rotate tires as described but, as I’ve gotten older, I have it done at the place I buy tires. I watch the pressure and keep it at 36-37 lbs. square inch, as davesmopar suggested. I don’t intended to be argumentative. Glad many of you have not encountered this but I have - and on multiple vehicles, model years '88 - '13.
No worries. I don’t take it like that. You’re just explaining your issue, and people here would like to help you sort it out. Have you asked your alignment shop about it and have them inspect the tire wear? Or is that the tire shop you mentioned in your OP?
I have owned 3 of these minivans and my kids have earned many. This problem has persisted despite alignments. I have also had this problem on front drive cars. I believe the shop is correct that it comes from most of the miles is done lightly loaded and the only thing that minimizes it is frequent tire rotations. I did mine every 5000 miles and it helped.
I concur w/@Mustangman above, most likely the rear wheel toe-in is incorrect. It’s possible for a diyer to make an approximate measurement of the toe-in provided they have a level surface to work on. If OP is feeling inventive, that might provide a clue. One problem, the toe-in has to be measured statically, while in use it’s dynamic, changes as you go around corners, over bumps, etc. The suspension system design is supposed to correct for those effects. Abnormal play in control arm bushings, drop links, sway bars, bearings etc may prevent that from working of course.
Even I would look beyond just cold tire pressure settings! Make sure those are correct, for sure, but then go
deep:…
Cupped/scalloped shoulders is indicative of what I term CBB(cracked, bent or broken), as it might apply to suspension parts.
Has the van been on a lift and had each wheel grabbed by its tire and checked for play?
This test should be performed before even an alignment is done.
Tire wear patterns are a good tool to use for selling shock absorbers and wheel alignments, but those are usually not the remedy.
Some vehicles are more susceptible to wear patterns than others however what these customers usually have in common are failure to perform tire rotations and tire under inflation.
Six different Caravans with bent rear axles?
I had a 2014 Grand Caravan. The summer tires did not do that but the winter tires really did. I got those tires off and ran a different set of winter tires all year long. Those started to look funny after a couple years.
I have a 2019 Toyota Sienna handicap van with ramp and modified suspension and the three year old snow tires that I run all year are looking pretty bad and making noise. As soon as my new tires get made I’m changing them out.
My strategy is to get the benefit of free tire rotation without paying $130 a year for seasonal swapover. Three years and the $390 goes toward new tires. It’s not hot weather here. I store NO tires or wheels in the garage because I can’t do any work at all.
My 1999 Grand Caravan with 196,000 miles on it never wore tires, and it was used and abused, but I also rotated, balanced and aligned the vehicle every 3,000 miles as well as I always ran the best tires…
As I said in my 1st post, check the alignment, check for a bent wheel and or hub flange, if all good, make sure you are maintaining your tires, if still doing it, then start playing around with air pressures, and run good tires…
I’ve had three Caravans but never ever had four matching tires, so never really paid any attention to the condition you describe. I now have a Toyota Sienna with 330k…at least the fronts are matched, and the rears are matched, so I’m getting closer to doing it right! 
Given that you have noticed the issue on multiple vehicles, it seems to me that the problem is not with the vehicles, though the light rear weight of an empty minivan might, maybe, possibly, seem plausible. I’m dubious…
So I’m wondering if there is something about the roads you drive regularly, or the way you drive, which would have created the same issue in multiple cars.
For example, do you have an unusually rough gravel road, or a twisty / curvy road, or a steep hill, from home to relatively smooth roads? Do you live far from town and have several miles on challenging roads before you get to smoother road surfaces? Do you drive twisty roads with a heavy foot on the gas and the brake, causing your softly sprung minivan to lean hard in both directions on corners? Remember that leaning hard to one side in turns unloads the inside rear tire so maybe the rears are slipping sideways in turns.
I’m no expert, but I suspect that the explanation is rooted in something that remains the same when you change vehicles. I’m not saying you should change your driving style or move to an apartment in town, but maybe you just have to accept that your circumstances are going to wear down your rear tires more than normal. That’s not a crime.
The aforementioned tire shop was an occasion dating back 20 years or more. It was a Firestone store right off the freeway in downtown KCMO. I’d never been there before and have neve returned. That said, they were diligent and invested a fair amount of time looking for an answer. I don’t actually remember why I stopped there. It isn’t anywhere close to home. I haven’t ever visited that store again. The alignment shop is a body shop / mechanic’s shop / rebuilder whom I have found to be honest and reliable. If I can’t do it myself, that is where my vehicles go.
I have considered the reasons you note due to this being a problem on multiple vehicles. I’m going to start looking a Chrysler minivan rear tires in parking lots. Something has to be consistent. Through redesigns I’m not certain the minivan is the answer as the suspension is different. It isn’t tire brands. It isn’t roads because we drive the same ones, 90% paved in Kansas, so not a lot of hilly, curvy, winding stuff. I have been dragging a sick of water softener salt around but hate the the prospect of getting clonked with a flying 40 pound sack of salt pellets in the event of an accident. The last couple of these things have had stow and go seating so the weight of the seats is still present. Perhaps it is us, but we go pretty slow these days and don’t careen around the corners. Kansas roads aren’t great and the winters take a toll on the surface.
That sounds like a “jack-of-all-trades” shop. Nothing wrong with that 90% of the time if they’re reputable. But I’ve got several shops around me with “Alignment” literally in the name of their business. There are specialists who do more than just throw it on the rack. (One of these places - local and reputable, but not specialists in alignments - once told me that my rears couldn’t be adjusted, even while there were kits that could do it. I needed a specialty shop).
So, like 20 yrs ago you asked a Firestone place about your weird tire wear, and on a whole different van. You need to go to a specialist alignment shop with your current van and current tire wear, and have them look at it all and sort it out.
In the meantime, no harm in looking at other tires on similar vans. But it doesn’t matter one way or another. The “story” doesn’t change. If the tire wear is as you describe, then you have an alignment/suspension problem. And if it is a common issue on the “Town & CaraVoyagers” then the kits are out there, and they should know about them.