After draining and refilling with Mobil 1 Synthetic ATF, my 2K auto at 31k was rough under deceleration. as it jerks down****fing. But curiously it only happens downshifting from 3 to 2. I took it to the dealer today, after test driving and further investigation, they offer to change the valve body under warranty.

I was wondering why it happened right after I change the ATF? It was perfectly smooth before. Was it my fault?

I'm clueless but, what is a valve body?
Does is has to with solenoid, TCM, and the so much talked about transmission problem?
After this fix, should I be worried about future break down? Will it occur again after 30k more miles?

P.S. searching with "valve body" didn't help much.

 

check out my home page for some picture of the valvebody (vb and search "vavlebody" as one word)....to my understanding, the vb is not a wear/tear item and what it does, it acts like gate keeper to control the passages for ATF to flow thru. I think ur dealer wants to change to solenoid....but they might be lazy and change the entire thing since solenoid is attached to the vb. TCM is an electrical control to the tranny....located behind ur air conditioning.


after I change my ATF to redline synthetic....I noticed more sharp response on upshift AND down shift.....I think this is porb why u feel the deceleration since the downshifting is more responsive.

 

So, should I ask them to change the TCM? Is it a good thing that they are changing the valvebody? Should I be concerned with future problems?

As for the downshift from 3 to 2, it is a "hard" downshift. It feels like you dump the clutch abruptly in manual. But overall the auto feel much smoother.

I assume that all the new SyntheticATF I put in will be replaced by whatever they put in. Should I change back to Synthetic ATF immediately?

 

if ur TCM is not a current version...I would suggest u to change it....but u have to convince them to do it under warranty. and about the valve body....I wont touch it if there is no problem with it...ask them in detail why the valvebody needs to be replaced.

if they changed it.....just tell them u just replaced with mobil synthetic ATF and wants the same for ur repair....if not, they should at least take off the ATF charge so u can bring ur own ATF.

 

I took my Max in for the trans TCB and thought I would have them change me over to synthetic ATF (I provided the ATF). I was told that for a warranty fix they would have to use their own ATF. I will have to pay for a trans flush to get the ATF.