strange transmission problem and theory

Definitely worth a try. What have you to lose?? The theory sounds plausible.

That's how I was approaching the situation. I'll certainly open it up tomorrow after work and see what's going on in there. I just can't think of any other good reason why it would do what it's doing. There are a few weird things about the situation. It seems like when a transmission is failing, it will wait for a moment and then get itself together enough to start going down the road. This one will go at full power and then stop.

Other info please? Transmission rebuilt previously and when? Fluid and filter changes at what intervals? Which fluid was used? Any other symptoms or error/diagnostic codes? Did you check the fluid level? Was it possibly overfilled causing it to whip up the air bubble mixture? Was it low?

Bob

As it turned out, the reason why the transmission couldn't draw fluid was because of a clogged filter. I changed it and the fluid, just to see what would happen, and the van ran great again, for about 30 minutes and about 20 miles. Then it had another attack. This morning I decided to see what it would do, and now it won't do anything in reverse, but forward is normal except that it gets starved and quits, just like it did the other day.

Now I'm thinking that although it has lost its reverse gear, if I replace the filter again it would probably go forward, just like another van that I used to have. I used to drive that other van all over town and it worked normally, but I just couldn't back up.

I'll replace the filter again and see what happens. I'd much rather have a no-reverse van for the cost of a filter change or two than to replace the entire transmission, at least for now. After I get a spare vehicle I might go ahead and tear into this one and see about getting it to work normally.

Hi Robbie,

I think your just wasting fluid. I think what's happened is you have had a gear failure, such as the front sun gear that failed on my transmission, a pic of it is here:

If the trans was in limp mode then you would have reverse. No reverse means something is broken and you have metal fragments throughout your trans lube system.

At this point, if you keep pushing it your taking a risk that your going to bind up something hard at speed and the transmission is going to grenade itself, and be completely worthless as a rebuildable core, so if you ever do want to get the thing fixed your going to have to pay even more money. However there's a minor possibility that this has already happened, and there's also a small possibility you could nurse another year out of it - if your intending to just take it to a wrecker when the transmission finally dies, then you might not care.

If you feel up to it, a trans replacement is not that difficult espically on a FWD van, why don't you call around to wrecking yards and see if there's a good transmission out there?

Ted

You could be right, but I did put about 50,000 miles on the other no-reverse transmission before it died. I thought it was worth a try with this one. There's a junk yard nearby that sells transmissions for under $100. The only problem with that is that you don't ever know whether it's a good one or not.

I took the pan off again, and it is full of shredded metal, after I cleaned it out thoroughly Wednesday. I'm wondering now, if it has a bunch of chunks on the bottom but it still drives forward and shifts, is it likely to lose the forward gears as well, or could it work just like my other van?

The luck of the draw.

Te

Here's the end of this story. It went forward for about 50 feet and then quit, and now it's finished. I'll have to decide whether to put another transmission in it, or if I just want to sell it for cheap to somebody else who wants to put another transmission in it. It's a nice enough van, an 89 Grand model with all the accessories and they all work. Tough choice...

It depends. Does this have the 2.5 Turbo or the 3.0 Mitsubishi? If it's the 2.5 Turbo, then by all means, hang onto it. You have the non-electronic 3 speed transmission and that combo is desired by turbo minivan fans! You can rebuild that sucker, boost the boost and take it down to the local dragstrip and collect pink slips all night long if you have a mind to do so. ;-)

But if it's the 3.0 Mitsubishi, which if it hasn't had the heads rebuilt, it will need it soon. I'm gonna assume it's the 3.0L with the Ultradrive.

89 Ultradrives had a LOT of parts changed in them in later versions, here's a list of some of the majors:

early '89 had 3 sealing ring reaction shaft, was updated to 4 sealing rings in late 89

revised input clutch hub

parking sprag bracket changed from stamped steel to casting

cooler bypass valve added in late 89

O/D piston upgraded to 4 slot pistion in 1990

10" torque converter introduced for the 3.3/3.8 ion June 1990

1990 input clutch upgraded to more durable

thicker transfer shaft in 1991

input shaft spline changed from 24 tooth to 22 tooth in 1991

new transfer gear design in may 1991

new valve body in 1991

CCD bus system introduced in 1992 - the TCM for 92-95 is different than 89-91

1993 removed speedo pinion bore, went to electronic speedo

more durable bonded clutch disk in converter in 1993/1994

differential gearing changes in 1993

And a word also about the transmission computer. If yours has the original computer, that computer needs to be replaced with one that has newer firmware. For the 1989 year and 3.0, the number to use is 4796121. If your trans computer does not have this part # it is the original one, and that firmware has a bug that causes the transmission to prematurely wear.

the cheapest and probably best way to handle this one if your going to keep it, is to find a '91-92 transmission from a wrecker that has the connection for the mechanical speedo and is currently hooked to a blown 3.0L of which there should be a lot of in the wrecking yards. Keep your existing transmission under the bench in your garage, and put the wrecker one in and it will probably fail in 20-30K miles, right around when the engine is going to be done.

Then you will have a core that has at least some of the upgrades and you can take both blown transmissions to a rebuilder who can tear both of them down and probably find enough hard parts that are salvagable between both transmissions that they won't have to go out and buy gearing or some such, which will drive up the price of the rebuild. At the same time you can get the engine rebuilt. What you will end up with is a $5,000 bill that will buy you a warranteed powertrain that will probably last another 150K miles.

Whether such a thing is worth putting in your existing 89 body is an entirely different issue. First question is, do you need a minivan? They are handy things to be sure and I have found I like driving them, but if you don't have kids, or your kids are grown, that removes a lot of the incentive to have one. Second question is, just how good is the body? Is there peeling paint? Is the paint still glossy? Is there rust? Has it ever been in an accident?

Here in the Pacific NW it is quite possible to get a specimen that has always been garaged, and driven by the proverbial little old lady, which looks like it rolled off the assembly line

6 months ago. It's not common, though, but it's possible. It is, in my opinion, quite justifyable to do a complete powertrain rebuild on something like that, people do them all the time.

Ted

Wow, you've put a lot of thought into this. And wow, they sure did a lot of work on that transmission design in just a year or two. Thanks for the tip on getting the 91/92 transmission.

The particulars on my van are: 89 grand voyager, overdrive, loaded with power options, leather seats, etc. Everything works great except the transmission, which is in fact the overdrive model. I'd have to run outside and look to be certain, but I'm pretty sure it has around 150k miles on it. I bought it at the auction about 8 months ago for $450. (I saw a 1990 that looks like its twin go at auction last week for $450, so no shortage around here.) The body is impeccable, assuming that you like white with fake wood, which I don't particularly. The 3.0L engine runs beautifully with no smoke. The underside is so clean you could eat your lunch off it, if the van happened to roll over. I have replaced the shocks and struts, power steering pump, fuel filter, master cylinder and two rear brake cylinders, as well as the pads and shoes of course. My total investment is around $650, and I put around 20,000 miles on it already myself delivering X-rays before my wife started driving it. We have two kids, and we like throwing bikes in the back once in a while for a family outing. The Dodge minivan is the most practical vehicle in history, I think. Too bad the transmissions are problematic.

I drove a 1988 powertrain installed in a 1990 van to 275,000 miles a few years ago, and my instinct tells me that my current van would be good for a good long time to come if I were to fix it. Although there seems to be a limitless stream of these things coming through the auctions I hate to junk this one, because it's such a great specimen. It is Chrysler minivan #12 for me, and it's the cleanest one yet, with the most working equipment. Obviously it would be a good one to fix, rather than selling it off. The question is whether I want to get 150 bucks out of it and spend another $400 to $500 on a different van or bite the bullet and spend all day saturday crawling around on the driveway heaving a transmission around. For the past 5 years or so I've been able to just about break even on cars. The only thing that costs me money is minor maintenance and gas. I've already made $800 on one van and lost $100 on another this year. I'll just have to decide whether it's worth the effort to save a couple hundred and keep my average up.

Thats about how much longer it should have stayed in R&D instead of being rushed into production in '89 :-/

And people say the age of miracles has ended! :-p The 3.0 bottom-end is actually reasonably reliable though not in the same league as the Chrysler-built engines, and it will go a remarkably long time on a timing belt too. The top end was the problem area, and if this one isn't smoking then its almost certainly been through the mill of valve guide fixes.

The later ones aren't, nor are the Chrysler-built 3.3 and 3.8 engines.

Reparing (if done right with all the best combination of parts) is almost always more cost effective than selling a non-running vehicle and buying another used one with another set of unknown problems.

If I were you I'd fix it. The reason is that in my opinion, while there's tons of these vans on the used market in the under-$300 range, just about all of them have transmission trouble. They are vans that are either lightly driven with the factory transmission that has blown chunks, or they are more heavily driven with at least 1 rebuild already done on the transmission. Keep in mind that there's a lot of transmission rebuild places that don't know what they are doing with these, still.

The companies that sell "rebuild kits" these days, which many transmission shops use, include all the updated parts and instructions on how to retrofit them in. However, about 8-10 years ago, these companies simply didn't know enough about mods that this transmission needs to make it solid. For example, there are still places putting in the light-duty 9 inch converter into rebuilds - this is crap, the 10 inch converter is what you want. That is why there's so much stuff out there that is in great shape except for a blown tranny.

If you unload this one and buy another, you have a good chance of getting a transmission that lasts maybe 10K and blows up again. Also, another used one your going to have to probably replace all over again all the piddly stuff like the struts/brakes/etc. etc. Since you have already dumped in the money on that stuff if you fix this one you won't have to do it again.

If your thinking of doing the R&R yourself, you should take a look at the writeup I did on mine when I did it this summer, it's here:

You can R&R the transmission in a driveway if you have the right tools, I did.

Ted

Yeah, I did it before on a 93 van. It's not hard to do, just tedious. The great news is that my wife is encouraging me to fix it so we can work on it together. I know a lot of folks would say that's a bad thing, but not for us. It will be fun.

I'll be looking for the 91/92 transmission as you suggested. What code numbers am I looking for on the bottom of the case?

Most transmission rebuilders scratch out the codes so I am not sure how well this will help, but here's what is in my 41TE/AE book:

First, look at your existing one, there's 2 possibilities:

1989 4446 659 1989 1/2 4531 664 both are Overall Top Gear Ratio of 2.36:1

The better one to have is the 1989 1/2

The production numbers for the transmissions that should cross are:

1990: 4531 551 OTGR 2.36:1 1990 1/4 4531 681 OTGR 2.36:1

1991 4567 848 OTGR 2.52:1

1992 4659 360 OTGR 2.52:1

1991 was when they put the newer transfer gears with the different helix angle those are more durable. 1991 also got the new spline converter and the internal bypass valve and the new valve body. This is probably the best year to look for.

1992 and later used the CCD Bus trans computer, a 1992 trans computer from a wrecker will not work in yours although the 92 trans itself should.

Note on the computers: if your computer is not a 4796121, it is a factory original; REPLACE IT. Find a 4796121 in a yard. When you do this you have to cut wire "cavity 49" of the TCM harness, this is per TSB 18-24-95

Now, you may see Chrysler rebuilt/service replacements, those numbers are:

1989 4531 687 or R4713 052 Note on this is "used 89 TR (Transmission Range?) & PN (Park Neutral?) Switches", I suspect a different year will have these located in a different place or perhaps a different connector?

Take lots of digital pictures of your existing transmission before going out to the wreckers.

Most of these vans have been through at least 1 trans rebuild, and since the rebuilders modify internal parts, they will scratch out the original service numbers on the transmission.