No Overdrive....

[Aqua Roach]

Hey all! Long time no post!

Awhile ago I completed my own Gen 4 swap with a 3.2l , ATX. Before ditching the ATX for an MTX, which won't be for awhile, I just need to get this thing running up to par. Everything in the car works perfectly, motor runs strong and its thrown only a few codes to things that aren't plugged in at times.

But with all that said the car never shifts into overdrive. I've gotten even the button wired in as well with the original shifter, I've run wires back over and over so I know things should be in their stock form.

I don't have an O/D Off light wired in, but I did probe the circuit with a test light and it seems that the O/D light remains on at all times, right after start up.

I don't know if a broken c-clip on the servo is responsible for these symptoms, but I didn't want to take it apart if its some kind of sensor or wiring issue. Ive been looking for a step by step how to guide on the clip, but the good one I found has broken picture links.

Thanks for the help! Hope we can solve this!

 

[sperold]

Here is an old write-up from SHOtimes that will help:

A big thanks to Doug Lewis and Micheal Anderson! My 93 ATX had lost 4th. gear but otherwise worked OK. Micheal posted the same problem and Doug was able to figure it out. The C-clip on the O/D servo had broken, preventing the transmission from shifting into 4th. gear. The O/D servo cover is on the drivers side of the transmission on the firewall side, down low by the steering rack. Remove the drivers side front tire and you can get to the 3-8 mm bolts on the cover. I removed the cover and the servo, found the broken clip laying inside the transmission. Replaced it for less than $1 and now have 4th gear back!

 

[Aqua Roach]

Servo looks good! A little rust on the aide of the piston thing but nothing that big spring can't push through.


Hmm if that's not the problem, any clue what could be? I have a spare PCM I'll swap into it and see if anything changes, but somehow I doubt that's the problem....

 

[rubydist]

if the o/d off light is always illuminated, that suggests that there is a short somewhere that is tripping the o/d off circuit.

keep in mind that each time you start the car, it automatically assumes you want to have overdrive and you must manually select o/d off. so, if you never have o/d, that means that something is preventing o/d each time the car is started.

I would be looking in the circuit for the o/d off switch, to see if it is wired properly or if there is a short somewhere, etc.

 

[Aqua Roach]

Being just a momentary contact switch I've checked it for voltage at the PCM and it seemed to work correctly, but I'll recheck it in case I over looked something.

 

[Aqua Roach]

I swapped in another PCM and still nothing. I had two questions though.

First, there's a hole going through that servo piston, is there something supposed to go there? I just stuck the thing back in not paying attention to any orientation, wondering if I screwd something up....


Also, I was reading somewhere about the AXOD-E that it had another clip in the valve body area....anyone have any experience with this? Thanks.

 

[rubydist]

yes, there are numerous clips in the valve body, some of which were issues in the 96-99 era tranny but I have not heard of that being an issue in the 94-95 tranny.

 

[Aqua Roach]

Okay so I found out with the OD it was a wiring problem. There was very little stray voltage on the line causing it to always be off. Fixed it with a direct wire from the button to the PCM.

But, now I have OD, the car doesn't like it. With OD on, it sometimes slips out of gear, and sometimes doesn't want to downshift when WOT. Shifts are nasty and harsh too.

If I turn OD back off, she runs fine and smooth. Shifts great and downshifts.

Its a relatively new torque converter, but the only thing I can think of that I've changed is the overdrive solenoid. I had removed it and reinserted it awhile back, and I'm hoping I put it in right. Was there some sort of alignment for it? I know there's a small pinhole on the piston arm, was that supposed to go a certain way?

Thanks!