transmission fluid level on dipstick

[doitmyself]

I feel rather silly asking about this, but I have NEVER had to top off my transmission fluid between 30K fluid changes. I see no evidence of any leaks this time.

I'm looking for possible causes for a rough transmission (I think)shift at 47mph, sometimes a bump when sitting still at a light, and sometimes roughness above 60mph. 05 Caravan with 45K, 4cyl. eng.. Maybe its another problem, but the consistent roughness at 47 suggests transmission to me.

Simple things first - check fluid level. After one hour of driving in SUB FREEZING weather (20 -30F), should the dipstick level get up into the "hot" marks??? Mine only gets up to the top of the "cold" mark. There's a good 1 inch separation between the "cold" and "hot" marks.

I'm thinking it could take a good 1/2 to 1 quart to get it into the "hot" marks.

The manual says the fluid should be uncomfortabe to the touch when hot. Mine feels just warm when checking.

I don't want to overfill the transmission either.

Any opinions are welcome. Thank you.

 

[Kestas]

The transmission fluid temeperature is regulated by the coolant. This serves two purposes -- it cools the fluid when it's hot, and it warms the fluid when it's cold. After an hour of driving, I would expect the fluid to be at least warm in this weather, and between the cold and hot marks. Are you checking the level properly?... level ground, engine running, car in park or neutral?

You could probably add a half quart without worry and see if the problem goes away.

 

[PRND3L]

IIRC the 4 cyl. vans have band adjustment as routine maintenance. Have yours been adjusted? Funny you should bring this up; we've had cold snap (relative for here anyway) and I've really noticed how my van has been running much cooler. I topped off my transmission fluid today too, but I have a weeping gasket from the last pan drop.

If it were me I'd add some fluid.

Also search allpar forums if you haven't already for those with similar symptoms.

 

[doitmyself]

"Are you checking the level properly?..." are you trying to tell me just because I can design, engineer, and carry out a multi-level project that I can't check the transmission fluid??? Just foolin - but that's why I'm asking here....haven't we all over-looked the obvious on a trouble shooting mission!

Yes, the fluid was changed at 30K, parked on a level garage floor, and I did the whole "check level" procedure outlined in the owners manual.

I know I was anal about the correct level at the 30K change.

You read my mind about the fluid temp. regulation - I wondered if the transmission had it's own regulation system. So, if the engine oil and coolant are up to operating temps., the transmission should be also.

If it is low, where did it go?

I'm almost ready to add the 1/2 quart. I'm just trying to do better than "replace parts until you fix it" strategy.

Band adjustment??? The new 4 cyl. come only with the 4 speed electronic transmission. I think the band adjustment was limited to the very reliable 3 speed, no longer available.

Thanks guys. As we say at work, "you have a keen grasp of the obvious"!

 

[SHOZ]

Probably only a pint difference between the two. The radiator adds no appreciable heat to the transmission fluid. The radiator ATX heat exchanged is on the cool side of the radiator.

 

[boxcartommie22]

what is IIRC?

 

[PRND3L]

"If I recall correctly."

Sorry doit... didn't know the transmission had changed..

 

[alreadygone]

Add a pint, can't hurt. Also drink a pint (different fluid obviously) might help.

Bob

 

[doitmyself]

I added about 10 oz., which brought it into the "hot" zone on the dipstick.

No changes to shifting. During the test drive,I tried operating van out of overdrive (3 on gear selector). Rough shift occurred at a lower speed (35 - 40mph)and less noticeable.

Next step is "off to the dealer".

Thanks everyone.

 

[Ramblin Fever]

Before you go to the dealer, have you hit any hard pot-holes or anything lately?

Reason I ask, is my sister's caravan '97 was shifting funny too, come to find out, it wasn't the transmission but something to do with her suspension as she had gotten turned around in our last blizzard - Colorado, and ran over the corner of a median. Every time the transmission would shift, the van would jerk, causing us to think it was the transmission.

Just throwing ideas out - we all know how scary transmission issues can be.

 

[brianl703]

I wonder if disconnecting the car battery for 10 minutes make make a difference. Couldn't hurt. All the new automatic transmissions have adaptive shift strategies which rely upon data kept in battery-backed RAM inside the ECU. If this data was corrupt, it could cause problems.

 

[doitmyself]

Thanks for the ideas. I have thought about disconnecting the battery, but I need to study up a bit more to make sure I don't screw something up and end up having to take it in for reprogramming.

And, the plot thickens...symptoms have changed. On top of the still consistent rough "shifting" at 47mph, now it sometimes sputters when stopped at a light AND when trying to accelerate (gently) while cruising above 60mph.

These latest symptoms seem more like fuel or electronic ignition problems.

I'm stumped. Will OBDII find codes if no light shows up on the dashboard?

 

[brianl703]

If it's a pending code, yes.

 

[TallPaul]

Unless you are under warranty, I would take it to a good independent shop. In my experience, dealers charge $85 an hour, whereas independent shops charge $65. Also, at 47,000 miles I would get the transmission fluid and filter (internal filter/screen) changed. I would consider a very high quality ATF like Redline. But may as well have the problem diagnosed first.