Overdrive or No overdrive? That is the question..

[Brett F.]

Ok so my '96 XLT is giving me a headache. I searched but didn't see anything really related so...

When I put the auto tranny in drive and count up the gear changes I go to 4.
When I put it in Drive with the O/D button depressed and the O/D off light on I count up to 4.

So do O/D off still go to 4 with different speed shifts for pulling or is something wrong?

Any idea on what to check?

Thanks.

 

[jlsparky7]

I dont have details about overdrive but heres the idea of it.

Overdrive is kind of like a 5th gear but the shift to overdrive is extremely smooth. the vehicle is only going to use o/d above something like 55 or 60mph (maybe someone knows the answer). If you have stock gearing and tires when your going 70mph your rpms should be at 2,500. If your up at 3,000 or higher your o/d isnt working.

 

[Brett F.]

If that is correct, and someone please chime in that knows, that would explain the almost 3000 RPM's at 70.

I do count rpm drop and feel to count up gear changes so I know 4 is all it's getting.

Hmmm

Every time I turn around I feel taken on this explorer.

 

[Earl43P]

Get up to a steady hiway speed, note tach reading.

Press the OD switch, light comes on saying "OD OFF", note rise in rpms on tach.

If that isn't happening, you aren't getting a shift into OD.

Maybe do a bit of searching over here: http://www.explorerforum.com/forums/forumdisplay.php?f=109

 

[Brett F.]

Ok so even after searching on 96 xlt no OD, 4r55e no overdrive, and just no overdrive i'm still in square one.

Let me rephrase the issue.

I put into D no o/d off light and from a standstill i go through 4 gears.
I press the o/d switch and light goes on and from a standstill I go through 4 gears.

On hwy in o/d if i turn it off the light comes on and no difference in rpm rev.

with light coming on i know the o/d switch is working on shifter. (found that in searching) And with the selector being in the dead middle of the letter on the dash and working as it should i expect that the selector cable isn't stretched.

thanks for a little more help please.

 

[budwich]

if you are at highway speed and you depress your O/D button, you WILL notice a "large difference" in the RPM. Having said that, its only true if you actually made it into O/D in the first place. Of course, the rpms are "relative"... tire size, rear end, tranny slip.... but 3000k is on the high side for 70.... probably closer to 2500-2700.

On the 4R55 (from reference), the O/D OFF light indicates that 4th gear has been disengaged... hence the "large difference" in rpms. I suspect that in your case, your "detection of shifting" is gears plus torque lockup.... BUT you are not getting 4th gear.

Ultimately, your statement "Every time I turn around I feel taken on this explorer"... doesn't give me a good feeling. My first question thus is... how long have you owned this vehicle??? next, has it always shifted like this???? and lastly, how do you know that your tranny is a 4r55e????

I assume from the statement, that you aren't the original owner... :-( You are probably not going to be very happy as we continue down this trail.

 

[Brett F.]

You are right Bud I am not original owner.

I bought if from a guy i knew at church who "just wanted to get rid of it".

Supposedly has a new motor and trans. when the trans went out 2 years ago. Motor had a oil pan leak and he found a newer engine and trans together in an Ex that the rear end was totaled. Also had to replace transfer case the month before I bought if from him for $2000. I have put close to $1000 in it since I bought it.

Where can i look on the trans. its self and see the model number?

It has lots of pep for it to have 31" tires on it so gearing I don't even think is stock. Engine runs perfectly and it shifts smoothly.

It just worries me that with o/d off I still have 4 gears. Is something bad about to happen? I dunno.

 

[budwich]

While that explains "the rest of the story"..... actually not that big a deal....maybe.

Anyways, there is usually a tag on the tranny... at the back end somewhere... you probably have to crawl under and "poke"... I can't remember where I saw mine (during a fluid change) but it was there bolted on.

Anyways, back to your problem... I guess then it has always shifted like that since you got. First question, does your check engine light come on during the "crank / start" process. It should UNLESS BULB IS BURNT OUT... which may mean that it is "hiding" some faults... some could be tranny related.... although not all tranny faults show up at the CEL (actually on a few)... but could be useful.

However, that's probably not your problem.... your problem is more likely the "I got a newer engine and tranny on my OLD truck" problem.... nice problem maybe depending on WHO did the work. Long story short... I suspect the "worker" didn't do "some of the things" necessary to make the "new units understand" that you got an "old truck". I would look at the PCM as it controls the shift thru the pressure solenoid. IF no codes or flashing O/D's occur, then it is likely that the PCM "thinks" its doing its thing correctly for the "old engine / tranny" and its happy.... and maybe... just maybe that's why you don't get 4th gear which if you got 31's, you would be at a lot lower RPM. The other option is that the "worker" might have "reprogrammed" the PCM with some "performance shift pattern" (don't know if it possible, but I think it is) and wanted more pull and less gas mileage.

Anyways... that my guess and I am sticking to it. Of course, the other way is to take it to a tranny shop and they will tell if there are any actual codes in the tranny and probably quickly tell you that you have no 4th and "here's why".

 

[Brett F.]

going out to crawl under thanks bud for all your suggestions.

 

[Brett F.]

ok I got up under it and it looks like the gasket for the tranny pan is leaking. So i know I'll have to change it. I looked all over and I can't see a tag or a model number on it anywhere.

Where can i find this on the tranny it's self?

 

[budwich]

frommy truck cd .... tag is located "Located Under Extension Housing Bolt" not sure where that is and of course, they don't show a picture. Look around near the shift linkage area also.

 

[Brett F.]

Will do thanks.

 

[budwich]

just kind of squeezed under mine. The tag was on the left side (driver's side) back corner. There is also a manufacturing stamp on the side but the numbers don't look "familar"... more probably with respect to plant, date, etc.

 

[brickwall]

Try taping the brake while around 50mph with your foot still on the gas, the rpm should increase by 200-300 rpm to check your torque converter, this could be the 4th shift your feeling. As bud originally stated, push the O/D button while driving and see if the rpm increases, should jump around 700-900 rpm

 

[Brett F.]

It's been raining here since Sunday afternoon. I haven't been able to check that location but will do.

Brickwall, will try the break thing today on the way home. Currently going down the highway at 70 if I press the o/d off button the rpm's raise slightly not near what you are saying and then drop back down. (maybe for a second) At 3000 it goes up to about 3200. Almost like it tries but then bumps back up into 4th.

 

[Brett F.]

wow it has been a while but I finally figured out some things.

It is the 4 speed. Some one mentioned the torque converter locking up (budwich) would feel like a gear shift. Well that's what it is. thanks bud

No overdrive.

I took it by Mr. Transmission last Friday and they will test drive for free and he confirmed it. So now i am driving without o/d on for fear of screwing something up.

Now I am searching on a fix for the o/d. I know I saw a thread on replacing a solenoid inside the pan so now I am searching for that thread and how I might fix it.

 

[Willard]

Since you confirmed it's no O/D most of the time that will be a solenoid. Not too bad to do, you can do it yourself without much trouble.

Also now would be a good time to adjust the bands. You can find a thread on that here too.

 

[budwich]

But I think there should be a tranny code if I am not mistaken if you don't get a proper shift. That code may result in flashing O/D and / or CEL depending on things. That's why I think that you have a PCM issue (controlling the pressure solenoid used for shifts) which may be the result of the "swap in" of your engine / tranny and not sure what the previous work did with the PCM to make it "compatible". Anyways, hopefully you will get further.

 

[Brett F.]

Ok so i figured out either the CEL light is either removed or blown so I went by autozone to pull any codes on it.

P0761 Mechanical condition-solenoid stuck.
P0153 O2 sensor

So, now that I know what it is I am trying to find the part and most autozone advance autos don't carry it.

Has anybody done this and if you have can you rate it on a scale of 1-10 with the 4WD shift motor fix being a 3?

 

[budwich]

Ahhhhhh..... I guess you missed my question / comment a few posts back about checking to make SURE that your check engine light works.... that would have been a good "clue".