Tranny Woes Continue

[doitmyself]

Seems like the transmission forum is mostly for fluid discussions....mods move this if appropriate.

My '05 Caravan, 4 cyl., 4 speed transmission was rebuilt in September at around 103K miles. It had ATF+4 changed every 30K with filter changes every other time (much more than the manual's OCI).

About 4-5 weeks ago it was rebuilt AGAIN. The shop claimed the pump they put in was defective. The torque converter was replaced again also.

Yesterday, on a road trip, the transmission started to do the same thing again. At 70mph +/-, it drops into 3rd gear, then searches back and forth between 3 and 4 (it seems). There's a surge, with increased engine rpms.

I checked the fluid level and it was 1/2 inch ABOVE the full hot line. In my experience, that's about 40 ounces over filled. MY bad for assuming they had it correct.

Comments? Explain what over filling might cause. The shop owner said this transmission is vented and overfilling would not cause a mechanical problem.

This independent shop is very highly regarded locally and he said they rebuild tons of these particular transmissions. Returns hurt their bottom line also. They are taking care of me (18K, unlimited miles warranty), but I want education whether the over-filling is a concern.

Thanks.

 

[tig1]

You could always draw fluid out the dip stick hole. Also, how do you know your problem isn't electronic?

 

[doitmyself]

To maintain the warranty, I will let them take care of it. I can only hope it's a simple problem, but because it's acting exactly the same as the second rebuild, I am assuming the worst.

Sigh. First my wife has recurring breaks/"mechanics" visits, and now my van. Old age sucks for everything.

 

[bullwinkle]

Overfilling causes fluid foaming, bubbles, and eventual spewing out of the vent. I would pull enough out of it to get the level down to at least the full cold line (since MI shouldn't be very hot this time of year) & try again. Almost wonder if something else is at fault (speed sensor or other electronics)?

 

[demarpaint]

I agree with Tig1, it could be an electronic control or computer problem with the transmission. 40 ouces overfilled is a lot, but I don't think it is your problem. Have you pulled the dipstick after a drive and checked for bubbles in the fluid? You'll see them on the dipstick when you pull it. HTH

 

[doitmyself]

Haven't seen any air bubbles, a good sign, I guess. It only started to act up after about 40 minutes cruising on the highway. Nothing around town. It's cold here (upper 20F), so the transmission should be running on the cool side. And, the problem is intermittent and not dramatic. It will be parked mostly until they look at it Monday.

I will post a follow up.

I also inquired about a Magnefine after the second rebuild. They were "cool" to the idea. They said they install them on some transmission model rebuilds, but not on this particular one. I'm trying hard not to second guess the experts.

Thanks for the input.

 

[doitmyself]

THE SAGA CONTINUES. ADVICE SOUGHT AND APPRECIATED.

Two weeks ago they rebuilt "my" transmission for the THIRD time in 3 months. This time they said they put in a DIFFERENT rebuilt transmission with in line filter.

Yesterday, the SAME symptoms reappeared. It "searches" between third and fourth(overdrive)....this time at around 50mph vs. 70mph last time. There is also some "bump" in the 1st. to 2nd. gears on occasion that is new.

AGAIN, I checked the fluid level and it is higher than ever....a full 2 inches above the hot full mark (fluid is not too hot with cold outdoor temps. +/-20F.

Questions:

1. Whats up with the high fluid levels every time? Did they overfill or is this a condition of transmission failure.

2. Could ANY engine condition cause these symptoms? My plugs are due (not over) and when my mechanic did my timing belt last month (cause here?) he said my throttle body is "getting" dirty/near time to clean.

3. I really need advice how to handle this situation. My wife is ready to "get assertive" with them, but I need the problem fixed. What do I do???????? Money back, try another shop?

Thanks for any help!

This might be the straw that crumples my already stressed life.

 

[morris]

is that the one with a check valve in the coolant line? if so it might have trash cogging the coolant. the coolant lubes the bearings. after they fix it, they should use a heat gun to be sure the cool line is flowing. also have them remove the check valve

 

[dishdude]

Sounds like the radiator is leaking coolant into the transmission cooler.

 

[MrCritical]

I think you have an electronic problem, not a hard part problem. Either that, or they have a supplier parts problem.

 

[Donald]

Originally Posted By: dishdude
Sounds like the radiator is leaking coolant into the transmission cooler.


You can get a used oil analysis on the transmission fluid. A $20 used oil analysis will rule out a leak in the trans cooler. Might tell you other interesting things also.

 

[Donald]

Send a PM to Quest and ask his opinion. He is the expert on transmissions.

 

[doitmyself]

I always follow up, with the idea that it might help someone in the future, even if no one really cares

I spent the afternoon at/with the transmission shop owner. In a test drive I got the transmission to show its symptoms. His transmission code reader showed nothing. He then hooked up his engine code reader and discovered a bad throttle position sensor (no codes, but fluctuating voltage). He changed that and we will see.

More frightening (to me)....I opened the hood to show him the fluid level and it was WAY up above the high level, this time with bubbles. He gasped. They removed some fluid and he assured me that overfilling will not damage this vented transmission.

My Chrysler mechanic friend said that overfilling can "fry" the transmission. Who do I believe?

Its still under repair warranty. We will wait and see. The transmission shop owner didn't exactly instill confidence that the problem is solved.

 

[Challenger71]

If there is enough of an overfill situation to cause air bubbles in the fluid then it will cause problems you're experiencing. Speaking of fluid, how sure are you that it is even the correct spec?

 

[doitmyself]

If they don't know about ATF+4 then I am doomed!

This local, independent transmission (only) shop has been in business for almost 50 years and has a stellar reputation. They have the best warranty. Believe me, I checked all 4 local shops (no chain types) before choosing. But, if the tech. had a hangover that day......?????

I just can't "read" them well. They are reluctant to admit any errors on their part.

I have dealt with these "coincidental" symptoms before. A transmission repair, followed up with a bad TPS causing transmission symptoms?....a mechanics nightmare. I hope it's fixed and the high fluid did no damage.

FYI, the original transmission symptoms were not TPS related (I think). That time the transmission whined loudly and was not going into gear sometimes, huge "slipping" etc., codes were thrown.

 

[Ross]

Have they replaced the solenoid on top of the trans?

I had a 2000 caravan with the 4speed. Around 110,000 miles mine was doing the same thing as yours. I had it at couple of different shops. Everyone had a hard time figuring out what the problem was. This went on for several months. We did notice that when the fluid was cold, it would never do it. We tried everything from fluid exchange to auto-rx. NO luck. To make a long story short we replaced the trans with a mopar rebuilt. The shop looked at the old one and said the pump and something else was out of spec. Whe cold, there would be enough pressure but once warmed the pressure would drop, thus the downshifting and hunting to bring the pressure back up.

 

[CBR.worm]

Mine did that, but it was not a transmission problem. In my case the TPS was replaced first, it turned out later to be a bad head gasket that was causing me to loose power when hot under load. Didn't figure it out until it started overheating due to low coolant. It was diagnosed by two shops as a transmission problem initially, but I knew that it wasn't.

That was the end of that particular van. It was an older 3.0 v6. It served me well though, I think it was almost 300k at that point.