You guys might have been following my build. Ive now put on new belts, new alternator, new brakes, new gas tank and fuel lines, new carb, about 3 tires. Well finally I figured she was safe enough to drive out in traffic so on her maiden voyage I took her to dump some old drywall and junk at the dump. Well she did great! Until I tried to backup and realized I was stuck in the mud at the landfill. Well then the guy on the giant earthmover came and hooked up a chain and drug me back about 60 feet to get me out of the mud. Once I was pulled out, i started her up and she cranks and revs fine but the transmission wont engage. When i shift into reverse my back lights come on. But no gears engage, wheels wont spin! I had to get the tow truck to come take her home so sad! Where do I evem start? I dont want to send her to the junk yard!


Here is my wife sitting broke down in the landfill with my baby

Let me try a new image host. Photobucket has stopped working

(1) check your transmission fluid level.
(2) check your driveshaft. Will the van still roll if you put it in park without the parking brake? If so, you have a damaged driveshaft or u-joint.
(3) If you have fluid and the driveshaft is still present and in one piece then you need to look deeper. Start by adjusting the bands. If a band adjustment doesn't solve the problem, then it is time to pull the transmission and tear it down.

Now this is the crazy part. After towing it home I tried to get it to engage again. It seemed to want to go in reverse but just barely rolled a few feet . Well i just went back outside and decided to try her again after letting her sit. Cranked right up and went right into gear like nothing was wrong. What the hell! I havent xhecked the fluid . Ill have to look up how to do that. Thats crazy right. I guess letting it sit awhile fixed it. But i dont want it to happen again when Im out on a trip

I asked someone why it would not go into hear when it was hot and then it would after it was sitting a awhile. They said it could be the filter became completely clogged so it was getting no pump pressure. Then all the crud settled out and it could pump again. Any thoughts?

Uhhhh, maybe, but not likely. To check the trans fluid level you pop the hood and pull the trans dipstick with the engine idling hot in neutral or park (I can't remember which, it will say on the dipstick).

If the trans performance is related to temperature, you might have a fluid level issue, a fluid type issue, or something more serious. I strongly recommend you check your fluid level. If the level is good, I then recommend you either drain and refill the transmission with Dexron VI fluid and replace the filter and adjust the bands, or have a shop do it for you. I know the original owner's manual calls for Dexron III, but Dexron VI is superior in every important way and will work just fine in your trans.

If your van is old enough, you may have to pull the doghouse to get at the trans dipstick.

I just checked the fluid. It appears that it is low by a quart maybe more. The fluid was dark and I tried smelling it but wasnt sure what it was suppossed to smell like but it didnt really smell burnt. It was a dark red brown not a nice pink. Im assuming a flush and filter change is in order. I would need a shop to do a band adjustment for me.

Also the dipstick was under the doghouse. Went into gear fine and drove forwards and reverse. Weird

Good transmission fluid should be a bright pinkish red color. If it looks dark it definitely needs changing. If you hvae a shop change the fluid and filter and adjust the bands, make sure they use the right trans fluid. Many shops have 55 gallon rums of a mix of transmission fluids and they just put that in every transmission without caring about what the transmisison actually calls for. If you have a set of basic tools you can definitely change the transmission fluid and filter at home. You can also adjust the bands, but I understand how intimidating that can be. Automatic transmissions seem like black magic because there aren't any moving parts you can see and understand how they work. It took me years before I got up the balls to actually start working on automatic transmissions.

In any event, yes, get the fluid and filter changed and havbe them adjust the bands and kickdown lnkage.

What does adjusting bands actually do?

The bands in the transmission act like a brake shoe on rotating assemblies in the transmission. The bands have a friction lining on one side that is clamped tight against the rotating gear assemblies or drum in the transmission. The bands are applied at different times to make the transmission shift into different gears. There is a front band and a rear band.

I have found this diagram extremely useful in diagnosing what part of a 904 transmission has failed. It tells you what internal transmission parts are being used in each gear:



As you can see, the front band is applied when the trnasmission is in manual second gear or normal second gear. The rear band is applied in reverse and manual first gear.

Like any mechanical part, over time as the bands are used, the lining on the band wears away. Think of it like a brake shoe or brake pad. As the band lining wears, the clearance between the band lining and the part it clamps on increases and the force the band applies decreases. If the clearance gets large enough the band no longer clamps with sufficient force to hold the part it clamps onto stationary. When that happens the trnasmission ceases to go into gear or shift properly.

Adjusting the bands puts the bands back into the correct distance from what they clamp on and makes the trnasmision work properly again. So if your transmission has high miles (and your burnt fluid suggests the trans needs some attention) then adjusting the bands is a good thing to do if the trans isn't working right.