P0745

[My gfs explorer]

So my girlfriend called me while she was in her way to work. Said he car was shifting really funny and overdrive light was flashing.

Once we both got home, I drove it just down the street to AutoZone and checked codes. Only code was 00745. Did a little research and I think I found three potential causes, low/dirty old fluid, bad shift solenoid, or possibly bad servo.

I don't think it's a servo since those seem to come with more codes. I really think it's the solenoid, but I don't know the last time the transmission has been serviced and that's the far cheaper option, so that's where I started.

Bought filter and 5 quarts of trans fluid, as per what I've seen on a few YouTube videos, the little nipple for the drain plug, and went to service the trans.

However, after pumping in the five quarts and pulling the tube off the nipple, I got no drainage/overflow like the YouTube videos said I would. Thinking it might be low on fluid, I went back to AutoZone and purchased two more quarts, came back and pumped them in. Still no real drain. Again, thinking it may have just been REALLY low, I went back and bought two more and pumped them in, now totaling 9 quarts, and still no significant drain.

Have I messed something up or am I on the correct path and need to keep going?

 

[TechGuru]

Not sure. It does hold 12.7qts. But if it was that low I don't think it would have moved at all.

 

[My gfs explorer]

Is there any reason why it might not drain if it is filled correctly/over filled? Like being too hot or cold?

I did pull the tube to check for draining immediately after starting, and when I didn't see a steady drain after a few minutes, stopped and went and got more fluid. Then did the same thing. But I know the engine eventually got warm, so I'd think the trans would have to. But never got the real steady stream I saw in the YouTube video

 

[My gfs explorer]

Not sure if I should have just made a new thread, but I figured some of this information might still be important.

Since last post, the explorer has largely sat in my driveway and I haven't messed with it much. However my main car just broke down and may be down for a while, giving me new motivation to revisit this.

To my surprise and luck, with a jump, she started right up and ran fine. Went for a very short and low speed test drive because the brakes are a little iffy. Transmission obviously still slips, and I got new codes. P0731, P0733, and P0734.

Can somebody help me begin to diagnose this further? And if possible and needed, guide me in the removal and repair of the transmission?

 

[My gfs explorer]

Fixed the brakes and did another test drive. Seemed to shift normal at first, then o/d started flashing again and the shift issues. Will really wind out the gears and then a hard shift.

Something I noticed though, because the issue wasn't there right away, but then once it started it seemed to be constant,I thought they meant it only happened once everything warmed up. However, the car died at one point during the test drive, and the battery is completely dead so it erased all codes. When I got the car started back up and on my way back to my house, it seemed to be shifting normally again. I can try and verify this theory tomorrow if necessary.

Any help is greatly appreciated.

 

[My gfs explorer]

There were some other codes like low or high voltage that i thought was unrelated, but just in case, here are the screen shots.

 

[Argentimage]

Fix your battery First
All those codes are noise

Then Assuming you filled the trans correctly get the codes

The point is how did you change the solenoid?

Drop the pan?

How much fluid did you throw away?

 

[TechGuru]

Fix your battery First

I think you mean replace the alternator.

 

[My gfs explorer]

Fix your battery First
All those codes are noise

Thank you for the reply! That's kinda what it figured about a lot of the codes. However, unless absolutely necessary, it want to make sure I can fix the transmission issue first, before throwing money on all the little things I know it needs. I'm at the point I'm unsure if it is worth it to fix it, or sell/scrap it, and I think that largely depends on what comes of the transmission.

Then Assuming you filled the trans correctly get the codes

The point is how did you change the solenoid?

Drop the pan?

How much fluid did you throw away?

It's been so long, I can't be sure of the exact details any more sadly. I don't believe I changed the solenoid. I think i just worded it oddly in the first post. I believe all I did was a fluid drain and refill. As to how much I threw away, I sadly do not remember. So would first step be to reattempt that process? What is the correct process to verify correct level? From what I remember from a video when I did it last time, you are supposed to kinda overfill it and then with the engine running, let it drain and it will drain to the correct level. That sound right?

 

[Argentimage]

Yes

 

[My gfs explorer]

Yes

No reason to try to drain what is in there though right? Just add more fluid and check to see if it drains or the same amount or less than what I put in?

I went ahead and replaced the alternator. I'm trying to charge the battery to see if it's salvageable but I doubt it.

 

[My gfs explorer]

After replacing the battery as well and taking a test drive, these are the codes I'm left with.

 

[Argentimage]

How many key cycles
And how many miles did you drive?

What are the symptoms?

 

[My gfs explorer]

How many key cycles
And how many miles did you drive?

What are the symptoms?

Just one after code reset

Let the engine get to temp, then probably drove 10 miles. Maybe less.

Same as before. Seems mostly fine in the beginning, then starts revving higher and higher not wanting to shift, and hard shifting if it does shift. O/D light flashes.

 

[My gfs explorer]

Just got done filling and test driving. Only took a little over a quart to get a steady drain. Waited until it slowed to a steady drip like I've seen in a couple videos and plugged it back up. All this was done after letting it idle for ten minutes or more. So I think I can finally confidently say it has the right fluid level.

Took a test drive and everything was fine at first, for a bit I started to think it fixed it. I started to eventually notice it seemed to hold first out a little, a little under 3k rpm or about 22 mph, but still shifted very smoothly. Continued to just get worse until it holds first out until about 4k and has a really hard, jerky shift. Erased codes and it came back with the same 5 from before.

Where is my next step in diagnosis?

 

[My gfs explorer]

It seems to me like a rebuild in necessary. I've never done anything like that, but I'd like to attempt it. I should have everything needed as far as tools and jacks and that. But I'm not positive I'd be able to tell what is good vs what needs replaced. I also notice the full rebuild kit i see doesn't seem to come with absolutely everything. What I notice missing are solenoids and bands. Both of which, from my research, could cause my issue.

So I guess my questions are first, is there any more diagnosis I can do before removing the transmission and digging into it? Then if not, should I just go ahead and buy the rebuild kit and then buy anything else i notice that needs replacing that wasn't included? And I guess lastly, how likely is it I'll be able to do this, never having opened up an automatic transmission before?

 

[Argentimage]

hard to say on ones skill set & changing servo is easier iirc that a full rebuild


how good is the body?

 

[My gfs explorer]

I'm confident in my skills in general and have taken on advanced tasks before and am usually successful. This is just a all new realm for me, but I don't mind the challenge.

You don't see the rust until you look underneath. It's extremely high miles though. I think 315. However mostly everything else with the car seems to be great. No dash lights other than a brake light because the parking brake cable broke. Which i plan to fix if I can get the transmission working right. Just a couple other small minor things like front passenger window lift and driver front turn signal housing needs replaced. Battery gauge and coolant temp gauge are wonky, which I thought I fixed but I guess not. That's pretty much it though. That what you were asking?

 

[My gfs explorer]

Is there any way to test servos or solenoids with the transmission still attached? Or is it time to pull it and go from there?

 

[My gfs explorer]

Also, is the fact that it shifts perfectly fine in the beginning weird? Or does it possibly tell me anything?