I've done a little research and saw some pretty disturbing pictures where the spider gear pin worked its way out of the differential housing and ate through the transmission case. The good news (at least to me) is that its something you can check without pulling that damn transmission. It kind of makes sense to me because the leak from the bellhousing it's had since I owned it wasn't fixed with a new front seal, and it seems like now the pin could have come further out and started chewing up the case around the differential.

Seems like that was pretty common on this and other similar mopar high-mileage FWD auto trannys. And mine is definitely high mileage, around 237k, but it works great with the exception of the tranny.

 

Just a quick update, I got under it yesterday and took the bottom bolts out of the differential cover, which was all I could reach without taking the engine off its mounts or removing the subframe cradle. I let all the fluid drain (only a quart or so came out of the differential area) out into a pan, and closed it back up, and wiped everything off. There were some steel and aluminum filings in the oil, and here's the kicker, I left it sitting for a few hours while I did some other things (with no oil in the diff housing), came back and there wasn't a drop of fluid on the floor, where normally there would be a 2-3" diameter puddle after that amount of time.

So I am assuming that whatever is going on, it's got to be something with the differential or at least that part of the housing. Would anyone disagree?

I'm going to open it up all the way next weekend, and will take pics. Be great to finally solve this mystery .

 

I think you hit the nail on the head on this one as my sister had the same thing happen to her, pin came out and put a hole in the case.

 

didn't you notice any cracks in the bellhousing area when you put in the new pump seal?

 

I didn't notice a crack, but I was running so behind schedule that I was pretty focused on getting the seal replaced and getting the van back on the road. And at that point it was probably very slight anyway.

Question about accessing the differential cover without removing the transmission, is it easier to remove the big suspension cradle? Or I think I saw a post somewhere saying to just remove the front engine mount and lift the front of the engine to roll it away from the subframe, which sounds easier.

Also, I talked to the local chrysler dealer, and they do sell the pinion shaft and the case savers, do I need to get new spider gears too? Since this is cause by the spider gear seizing to the pinion shaft, I was thinking at least one would be too damaged to reuse. I only ask because all this stuff takes a week to come in, and I would prefer to pull it apart once.

 

I don't have an opinion on how to 'fix' your problem without removing the trans from the vehicle.

I have removed diff covers just as it sits in the vehicle. a couple bolts are hard to get at but with quality intelligent problem solving skills, there's always a viable solution.

a 10mm gear wrench is a must for this project. however if you find the pin has been compromised, you'll need to remove the transmission anyway to address the cracks in the case.

And you MUST replace the spider gears, you'll find they are badly galled as will be the pin.

just wondering if you live in a snowy/winter climate?

 

No, I live in middle TN, but the car was originally titled in Wisconsin so it's seen a little snow I'm sure. So the differential has most likely been abused.

I will go ahead and get the spider gears along with the other parts. I saw that you could reasonably expect to get the diff cover bolts out without removing anything else (and you're right, the ratchet wrench will pay for itself), but as far as getting into the diff something is definitely gonna need to move. I'll see what I can get with the motor mount and maybe the cradle too. If I have to drop the tranny I will, but I will moan loudly!

It will be weekend after next before I have access to the garage, I'll update on what it winds up taking. And I'll have the greasy camera handy as well.

 

how do you expect to fix any cracks without removing the transmission?

 

The holes were cut from the inside of the differential housing, I figure that's the logical place to patch them. Most likely fast steel

 

how do you plan on cleaning the metal sufficiently enough for that stuff to adhere? and you need to remove the diff to get in there which is NOT possible with the trans in the van unless you pull the k-member. and if you think you can pull the 3 trans mounts and drop the the trans at an angle, you'll break the power steering pump off on the frame rail.

also if you try this putty patch on the inside, there's about 1/8" clearance between the diff and the bellhousing near the pump, you'd have to make sure your build up isn't to high,

basically, I see more problems trying to get around dropping the trans than it's worth.

Once you verify that indeed the diff pin is the problem, do the smart thing and drop the trans, then you can fix it right. for me it it only takes 40 min for me to drop these trannies and and hour and a half to put them in. with no hoist.