1996 Legacy LSi EJ18 FWD automatic

nothing in the car is original, i swapped out the engine, trans, ECU, and TCU.

 

car runs and drives fine (it's REALLY fast!).

 

when i climb a really steep mountain, say in 2nd gear, like the really steep roads with switchbacks and all. when i floor it, it won't downshift, it just lugs in 2nd.

 

Any ideas on why it won't downshift?

Will it manually downshift? I think if your going faster than say 30 mph in 2nd it wouldn't downshift. That would put a lot of extra strain on the diffs. possibly causing damage.

Edited September 29, 200817 yr by screwbaru2

You're gonna have to get into the valve body for this one. (I've seen that job and I don't want it.) All the actual shifting is controlled by the multiple springs, plungers, check balls and how the fluid flows through the channels.

You could just swap in a valve body out of a matching transmission that you know shifts well and see if that will cure it. Very likely it will. But if there's any contamination in the ATF, it will get into that valve body as well and cause problems again.

 

Emily

http://www.ccrengines.com

ah the valve body. on subarus, they are really not for anybody but the specialist in this area, with a service manual.

I tore into a valve body on a bad tranny once, and the valve body is something I will never touch again on a subie. not a simple fix for sure. ..

shifts fine manually and i doubt it's the valve body.

 

what "tells" the car to downshift when going up a mountain? how does the computer "decide" to downshift? i'm thinking maybe i just need to swap the TCU to a different model.

 

or - is there a way to determine which transmission i have and match the TCU to it?

 

the car shifts perfectly manually and it's definitely not because of speed. it'll go straight into any gear i want too manually. it's not speed related, because it's obvious it should shift...barely lugging along up the grade when it should down shift.

sually there is a part number on the bell housing at the starter. a TZ102.... number? a dealer, if no one else, can tell you what it came out of.

1996 Legacy LSi EJ18 FWD automatic

nothing in the car is original, i swapped out the engine, trans, ECU, and TCU.

 

 

Just noticed this^. You put an EJ18 in a Legacy?

car downshifts fine normally, but not when going up a very steep grade.

and it downshifts fine manually. fluid is good.

 

the AT light does blink because it still thinks it's an AWD.

 

another thought - i don't have an EGR valve on this thing and i recall my OBS doing nearly the exact same thing when the EGR/that filter, were having issues a year or so ago. it would delay shifting...on the same hills.

 

wondering if the lack of EGR is affecting the shifting?

i'm getting somewhere by a strange stroke of luck.

 

a guy from the XT6 board that i haven't talked to in like a year emailed me with some questions. says his friend has a non-EGR EJ22 swapped Legacy (originally EJ25). here's the fun thing - he's emailing because it won't downshift when it's supposed to.

 

so - looks like this is a non-EGR into an EGR engine issue for the automatics. time for a new thread....

would be interesting to throw a vac gauge on the car and see what it is doing.

 

nipper

DANG IT!!!! it always comes down to a device i don't have or know how to use! are you suggesting it's an engine running issue or something else? i wouldn't think it would be engine related based on someone else having the same issue with the same swap and different issue?

hmm. yeah i guess i'm stuck on how well the engine runs every but those steep hills. daily driven, thousands of miles, highway trips, runs fine...just the hills. (same description from the other guy with a non-EGR swapped engine too).

 

i think you said before the MAP sensor may affect shifting and would be affected by vaccuum right?