Van is 93 with the 3.0 or similar, lots o' miles, no maintenance in forever, driven 60 miles or so a week, usually at lower speeds. I've experienced a problem randomly for the past month or so. I'll be driving over 45, usually just at 55, and it feels as if the tranny is dropping into a lower gear. The first time it happened I was 30 minutes into a higher speed drive with a few hills and I thought it was heat related. It happened a few days ago at the start of a 30 minute drive. What should I be looking for?

It may not be related, but when it happened the other day, I had just set the cruise. It cruised for about 1 minute when all this started and my cruise wouldn't start back.

 

Being low on fluid or fluid that is starting to smell burned because it is old or suffering internal failure.

 

Definitely check the ATF for level and color. But assuming that and the transmission itself are OK, there is something else that can cause what you experience.

I think that speed range you stated is right at the threshold of the torque converter clutch locking up. If you happened to be going around 45 mph with very little load, the clutch can lock up, but will unlock if you start to encounter load, such as an uphill, and the engine will speed up, but could still be in OD. Similarly, if you have heavier loads, you could force the clutch to stay unlocked up into the 50's. Does this happen at higher speeds?

 

I've noticed up until about 60ish. I haven't really driven it faster than that. Well, on second thought, the first time I noticed it I had been driving 30+/- miles between 55-70. I slowed down for a few miles whiles passing through a small town and it happened right after I topped the incline out of town and was back up to speed.

Does this clutch unlock and make you feel like the transmission dropped out?

 

When the torque converter clutch disengages, it depends completely on its fluid coupling, which I'm told has a pretty high stall speed. So you will see the engine suddenly speed up, but you should still get drive power. Did you notice the condition getting worse? Like, the engine spins much faster, but you're not going anywhere?

Also, if you suddenly let off on the gas pedal, it could take a moment for the clutch to disengage, and you can feel a short jerk, just like with a manual transmission.

 

Regardless, you should also get the fluid changed out.

 

I guess it is time for a fluid change. I just hate to take away from the originality of the van.

 

Tough choice, non original fluids will probably costs you 20% in value in the collector market.

 

Do you still have the original gasoline that was loaded from the factory?

 

Good point. You have me on that one. However, I think that I could scrounge up some NOS gasoline from 93 out of my other vehicles if I decide to hit the concours circuit!

On another note, I do have a 2000 model battery in there and I have a Sept 1995 battery on charge right now. Still looking for a late 92/early 93 battery.

 

Just a quick update...Trans has been shifting fine with no problems...Then it started again, didn't seem as bad though, and check engine light came on. I didn't really notice before, mostly because of the electrical tape over the light! I might just need a good overall tuneup. I haven't pulled the codes, but I assume that there may be some stored.

 

Hiding from the idiot lights........AWSOME!

 

I hate to bring this up again, especially since I haven't changed the fluid....I started getting that slipping feeling again. The fluid is brown now, but it is also overfilled. I've had it loaned out to family, so I must assume that it "slipped" with them and it was easier to pour in a quart of ATF than to check the level.

Will an overfill cause a feeling of dropping OD?

 

When was the last time you changed out the fuel filter, or is it OEM also. My 90 did something like this and after changing out the touque converter, it turned out to be that I forgot to change to fuel filter and it was pluged.

 

Fuel filter? I guess it would be worth a try. The fuel pump seems to make a lot of noise.