Can I trust the dealer?

I have an '06 with 95k miles and the tranny is starting to up-shift and down-shift a few times, sorta bumping, during normal acceleration at about 30-40mph. The little jolt happens when it is in Drive. It doesn't seem to happen when it is set in 4th. From reading this site, I suspect the problem is an intermitent solenoid fail. It does not do the bumping when it is cold within a mile or two after starting, but it gets worse as the car warms up.

The "Check engine light" does not light (except at the systems check at startup). The ATF is the original stuff.

I'm prepared to change the fluid myself and save an even 100 bucks (over the dealer's price) in the possibility that the problem is only worn-out fluid. But still, I have 132 bucks tied up in the fluid that may be dumped if other work proves to be necessary.

So, I'm wondering about three different possibilities:
1. Can the computer provide a code even if the CEL is/has not been illuminated to indicate a saved code?
2. What's the odds that a fluid change will resolve the problem?
3. What's the odds that I will be told I need a rebuilt A470E when the problem may be far simplier and easier to fix by a good mechanic?

A final point: About a month ago I installed a new battery. The computer was not flashed as i understand that can/must be done at such times. Could that be the problem?

 

If your Fluid looks good, is topped off and smells OK I'd bring it to a place you trust for a check/estimate. Nothing wrong with changing the fluid at this point, but as you said, you'd hate to throw money away with the oil. Perhaps others here have better insight than I .

 

change your fluid..... if its got 95k on it.... its about 35K past recommended use. 90% of the auto trans problems people report are due to fluid.

do the fluid change yourself, it will take a couple of batches as you are only able to get ~ 3 quarts out per pan drain.

 

I thought the service period for tranny fluid was 100k.

 

Change the fluid yourself. Here's the how to.

http://www.tacomaworld.com/forum/2nd-gen-tacomas/68462-diy-full-flush-automatic-transmission.html

I'm not sure how the dealer would do it, but other transmission shops I have dealt with don't throw out the fluid. If the fluid is in good condition, they drain it, store it, and put it back in when completed.

 

I hate automatic transmissions with a passion. So much to screw up. I've never heard of having to reflash the computer after a battery swap, only that the computer has to relearn things for a bit afterward.

Good luck with your problem.

From what I've read here, Toyota dropped the change interval down to 60k. Probably had something to do with people's tranny's taking a shit before their time.

 

I think trusting the dealer is like trusting any other shop. What's your past experience with them? What do people you know and trust say about them? And so on. If the vehicle is out of warranty, there is no particular reason to use the dealer's shop over any other.

If any shop, dealer or not, told me I needed a new/rebuilt transmission, I'd get a second opinion. For a high-ticket deal like that, I'd be more likely to use a well-recommended local mechanic than the dealer.

 

I went to the local dealer and discussed the problem with a service rep. I was told that if the CEL never has come on, then no data has been stored for the apparent problem. They seemed to think it was the fluid and no actual malfunctioning of the system as the reason for no code. I'll be changing the fluid in a day or two thanks to a great thread I've found here at TW. Dealer wanted $235 for the job. Thanks, guys,

I'll let you know if the fluid change saved me a quoted price of $4200 for a factor rebuilt tranny.

 

I don't believe this is totally correct. You can have "pending" codes that get set, but have not made it to an actual CEL as yet. Some codes have to be present for some period of time before they set a light.