'90 Caravan 4-speed auto problem

[Anonymous_User]

Now that I have a lot of time on my hands, I'm trying to catch up on some projects that have been sitting.

One problem is my 1990 caravan. It has a 4-speed automatic tranny. When I start it up in the morning (cold) and I shift into drive, it is just like neutral. If I rev the engine, it will eventually drop hard into drive. After this, it is usually good to go for the day. If not, it might stick in first gear going down the road in the morning. Shift to neutral, turn key off, re-start van, shift to drive and it is good to go.

OK, this is an electrically shifted tranny, right? I've never had one of them apart. This sounds to me like a stuck valve in the v/b or a faulty solenoid. I plan on dropping the valve body out to see if there is anything that I can service in there. Clean it up real good and what not.

Does it sound like I'm on the right track here? If I can't fix it myself, I'll give the van away for scrap, so I'm not real concerned about messing something up.

[turbovanman²]

Have it checked for codes, you'll need it scanned. Sounds like the typical seals gong hard routine hence it takes awhile for them to seal when cold. A can of luber fixer upper works wonders.

[Anonymous_User]

A can of luber fixer upper works wonders

???

Where does one get this super luber builder upper?

Are you saying a tranny fluid additive may help solve this problem? What seal is usually the culprit in such a situation? Is it a valve body seal or deeper in the tranny?

[shadow88]

1st things 1st. check fluid level when warm. Add if required. It sounds like it has a fault in it and that fault needs to be read with a scan tool and properly diagnosed.

Is there a whine that sounds like a low power steering system when cold?

[Anonymous_User]

No noises whatsoever.

I will not spend $$ taking it to a shop to have it scanned. The van isn't worth that much to me. It is very, very solid underneath, has a very good running 3.3, but that is about it.

[shadow88]

It sounds like your mind is already made up. It looks like it's going to be sold or scrapped. So why not try some additive "snake oils" to see if that helps you.
I'm pretty sure the old-timer at work told me to add a cup of varsol to swell up the rubber seals:confused: I've never tryed it, but it seems like you have nothing to lose.

[Anonymous_User]

Yeah, probably what I will do. Plan on dropping the pan, new fluid, filter, some type of additive. This van has been a storage shed for a year or more. I've only moved it from one spot in the yard to another. It is very solid underneath. I sure wish it was worth doing a turbo/5-speed swap, but there are too many other things. The manual windows don't go up and down anymore. The quarters are starting to rot. Headliner sagging. Etc.

Snake oil and a for sale sign. Might drop in some spare G-body struts and drop the rear to match. Might be able to get some $$$ for it that way from some kid.

[Vigo]

I work at a transmission shop and scan for free.. surely someone local to you does too.

As said, it seems your mind is already made up, but if you ever actually want to diagnose/fix a 604, pm me and i will try to help.

[turbovanman²]

???

Where does one get this super luber builder upper?

Are you saying a tranny fluid additive may help solve this problem? What seal is usually the culprit in such a situation? Is it a valve body seal or deeper in the tranny?

Its the additive cans, that claim they help which in some cases, they do. Usually the clutch pack piston seals get hard and brittle so when cold, they don't seal until the fluid rushes by and warms them a bit, then they finally seal and you get to move forward or backward.

[speedyshelby]

Not high jack the thread but in our shop at work we got a 94 grand caravan with the 4 speed and 3.3. The trans won't shift out of first. The scanner says that it has a fault in first gear. Also the speedo don't work any ideas?

[MopàrBCN]

Hi, send me an PM with your email. I have the Diagnostic Manual of the A604 scanned as PDF and MDI. What I do not have scanned is the Rebuild section. But at least you should get it diagnosed with it.

PS: Late engagement into first and up from then working fine in my judgement is a strong case for at least checking fluids. Also, it being a 4-speed dont mess about the oil you are putting. It must be ATF+3. And don't put anything else!!! No additives, nothing... This tranny is very prone to failure and very fussy about its oil! If you don't have an extra oil cooler, it is a must as well, if you want to get more then 60k miles out of it.