Overdrive(?) slipping when accelerating

[The_Epsicle]

I drive a 1994 4.0 Extended Cab Ranger, auto 4x4, auto tranny, Dana 35 front Ranger 8.8 rear, 3.73 gears, about 220,000 miles on the vehicle. The transmission was "professionally rebuilt" 200 miles before I bought it (there was a rebuild tag, not sure why it was rebuilt or how much of it was rebuilt) and now I've put about 15,000 miles on the truck.

My problem first appeared a few weeks ago as I was driving my girlfriend home. I felt a surge every now and then, the next time it happened I glanced at my tach to see my RPM jump up to almost 3K (originally somewhere in the realm of 2.2K) at 70mph, bear in mind the needle on my tack may be slightly off. There wasn't much I could do so I just drove her home. The next time I drove, which was a few days later, it did it again but more violently. I noticed that when I was off the accelerator (and therefore decelerating) my transmission seem to stay steady in 4th gear, but as soon as I touched my accelerator it shifted to 3rd. I moved the shifter into 3rd gear and just drove the rest of the way home like that with no problems (well, besides a leaky heater core...). When I got home I checked my fluid level and it hadn't changed since I left (EDIT: The fluid level has never changed, the transmission is sealed up pretty tight as far as I can tell.) , the truck has been sitting ever since.

I haven't had much time to think about this, and transmissions are not my area of expertise (My only experience is helping my brother replace seals on his Pontiac) After doing some research (a few google searches and a look at my chilton manual) I have a few ideas, in no particular order:

1. It could be my torque converter not locking up properly. Maybe something to do with my speed sensor?

2. It could be my kickdown cable is out of adjustment. (I don't know what this cable is.)

3. Something is wrong with 4th gear, either broken or becoming broken (please excuse my specificity)

4. Rear speedometer sensor is bad, or some other electrical issue.



I believe the problem may be related to some previous issues with the truck, both of which are still issues.

1. Cruise control failure (It seemed to only work when the tranny was cold before it died completely). (CLICK HERE)

2. Fluctuating speedo (replacing the instrument panel improved things, but the fluctuation has steadily gotten worse.) (CLICK HERE)

3. Right when I bought the truck the Accelerator cable was stretched so the throttle only open 1/8 of the way with the pedal to the floor, I put some zip ties on the cable as spacers in order to get the throttle to open all the way. Seemed to fix the problem and I've had no issues since then, but I'll leave it here anyway.


Let me know what you think. I'm about to start an engine rebuild over the summer since she's leaking oil like a sieve (a quart every 200 miles or 1 month), so anything's on the table.

EDIT: The overdrive band was out of adjustment. I bought two new band adjustment nuts and adjusted the overdrive and intermediate bands at the adjustment screws on the driver's side of the transmission. I tightened the nut to 120 in lbs and backed of two turns.

 

[The_Epsicle]

I've been doing some research and all I've figured out is that this transmission sucks. I am strongly considering swapping in a stock manual transmission from another Ranger/Explorer as a solution to this problem. I know there are a lot of things to consider with an auto to manual conversion but I've got the cash (maybe) and nearly three months to do this so I think I'll try and get started on it. Does anybody know anything I should know about doing this? For instance, is this a stupid idea?

 

[The_Epsicle]

In case anyone cares, I'm pretty sure it's the 3-4 solenoid but I won't have time to check for awhile.

 

[The_Epsicle]

 

[Tedybear]

Sorry you're having a hard time getting attention. Sometimes even I'll post a question under the 'need help now' (sorry moderators) due to some areas not being looked at very often.

Always start with the basics.

How does the fluid look and smell. I know you mentioned it's at the correct level and no leaks.

Do you have any local GOOD transmission shops that advertise a free check? We have a local company that has been around sense Moses was in diapers and has a great reputation. (big box store types usually are a "Gee it broke, swap it" variety and really are not my cup of tea)

The mention of the speedo issue rings a bell with ours. While I have a 95 explorer with a 5 speed standard. The speedometer gear itself was bad (in the transfer case) While it was acting up, the poor engine didn't quite know what to do? I sometimes downshift or engine brake.... Talk about shake, rattle and roll!! It didn't know the correct speed I was going...so it attempted to dial EVERYTHING back like it was sitting still. Now it's running decent.

Just wondering if the speedo sensor is feeding your power train computer bad info, it might be having problems with overdrive and/or torque converter lockup.

Just some ideas.....

S-

 

[The_Epsicle]

Sorry you're having a hard time getting attention.

Thanks for the reply and sorry I haven't responded yet, I've been working on a contract in Colorado and have been away from my computer.

Sometimes even I'll post a question under the 'need help now' (sorry moderators) due to some areas not being looked at very often.

When I first bought my truck in 2014 I almost always posted there, these days I'm trying to cut back. Everything I asked was common sense to experienced shade tree mechanics but I had only done basic maintenance before buying my truck. Now I'm looking at taking some ASE certification tests, funny how things change.

Always start with the basics.

How does the fluid look and smell. I know you mentioned it's at the correct level and no leaks.

Ah, I forgot to mention that the fluid is the purest color of cherry red you have ever seen and smells like... well, transmission fluid.

Do you have any local GOOD transmission shops that advertise a free check? We have a local company that has been around sense Moses was in diapers and has a great reputation. (big box store types usually are a "Gee it broke, swap it" variety and really are not my cup of tea)

I didn't even think of going to a shop, I'll look into it. I'm good friends with the couple that owns the transmission shop up the road. If they offer a free check I would probably pay them to do it because we both know I would fix it myself and I don't want them to waste their time.

The mention of the speedo issue rings a bell with ours. While I have a 95 explorer with a 5 speed standard. The speedometer gear itself was bad (in the transfer case) While it was acting up, the poor engine didn't quite know what to do? I sometimes downshift or engine brake.... Talk about shake, rattle and roll!! It didn't know the correct speed I was going...so it attempted to dial EVERYTHING back like it was sitting still. Now it's running decent.

Interesting. I think 95 is when they got a few more electrical bells and whistles to worry about, that doesn't sound too much like what I've got going on.

Just wondering if the speedo sensor is feeding your power train computer bad info, it might be having problems with overdrive and/or torque converter lockup.

While I do think my speedo gear might be shot for other reasons, I'm not sure that is causing my problem. The issue is exclusive to 4th gear and my tachometer jumps too much for me to think it's a torque converter issue.

I've been in Colorado for a few weeks (my employer drove me so my truck has been sitting) so I haven't even dropped the pan yet, but I found a notecard in my glovebox with some codes from a KOER test I ran in March when my transmission first started acting up. I would've posted these earlier but I never even looked them up in my chilton's because the problem went away and didn't appear again until May. It took me awhile to even remember taking the codes. Here they are in order of appearance with the Chilton's definition:

(Engine running)
75: Brake on/off switch failure (I assure you, my brake lights work)
18: SPOUT circuit open
618: 2-3 shift error
91: No heated oxygen sensor switching indicated, left side
75*: Brake on/off circuit failure
74*: Brake on/off switch failure

* There was only one code for the "*". It was late at night when I wrote these down. I wrote down 75, but it may have been 74. I'm not sure why it would repeat here or why the code is there because my brakes work fine as do my lights.

(Continuous memory)
176: Heated oxygen oxygen sensor indicates lean condition, left side
188: Adaptive fuel lean limit reached, left side

(My thoughts)
176, 188, and 91: These have been on here forever. I am pretty sure (as I'm sure you are as well) that I have a bad 02 sensor but I've been a little lazy replacing it as my MPG was pretty good. I'll replace it soon because it's starting to affect my MPG.

75/74: Not sure why it would repeat if it was two 75s, I'm also not sure why this one is there because my brakes and my lights work fine. Although, my cruise control does not work as previously stated.

18: This is a surprise. The engine runs fine and gets good spark, not sure why this one appeared.

618: Also a surprise since my issue seems to be in 4th gear. I'm really not sure what to think of this, but Ockham's razor would suggest that this is actually 619 for a 3-4 shift error and I missed a flash on my CEL.

I would take the codes again to double check my work, but I was stupid and cleared the computer in March. I'm not sure if half of them will even be there anymore because the CEL hasn't turned on since then.

 

[Tedybear]

Thanks for the reply and sorry I haven't responded yet, I've been working on a contract in Colorado and have been away from my computer.



When I first bought my truck in 2014 I almost always posted there, these days I'm trying to cut back. Everything I asked was common sense to experienced shade tree mechanics but I had only done basic maintenance before buying my truck. Now I'm looking at taking some ASE certification tests, funny how things change.



Ah, I forgot to mention that the fluid is the purest color of cherry red you have ever seen and smells like... well, transmission fluid.



I didn't even think of going to a shop, I'll look into it. I'm good friends with the couple that owns the transmission shop up the road. If they offer a free check I would probably pay them to do it because we both know I would fix it myself and I don't want them to waste their time.



Interesting. I think 95 is when they got a few more electrical bells and whistles to worry about, that doesn't sound too much like what I've got going on.



While I do think my speedo gear might be shot for other reasons, I'm not sure that is causing my problem. The issue is exclusive to 4th gear and my tachometer jumps too much for me to think it's a torque converter issue.

I've been in Colorado for a few weeks (my employer drove me so my truck has been sitting) so I haven't even dropped the pan yet, but I found a notecard in my glovebox with some codes from a KOER test I ran in March when my transmission first started acting up. I would've posted these earlier but I never even looked them up in my chilton's because the problem went away and didn't appear again until May. It took me awhile to even remember taking the codes. Here they are in order of appearance with the Chilton's definition:

(Engine running)
75: Brake on/off switch failure (I assure you, my brake lights work)
18: SPOUT circuit open
618: 2-3 shift error
91: No heated oxygen sensor switching indicated, left side
75*: Brake on/off circuit failure
74*: Brake on/off switch failure

* There was only one code for the "*". It was late at night when I wrote these down. I wrote down 75, but it may have been 74. I'm not sure why it would repeat here or why the code is there because my brakes work fine as do my lights.

(Continuous memory)
176: Heated oxygen oxygen sensor indicates lean condition, left side
188: Adaptive fuel lean limit reached, left side

(My thoughts)
176, 188, and 91: These have been on here forever. I am pretty sure (as I'm sure you are as well) that I have a bad 02 sensor but I've been a little lazy replacing it as my MPG was pretty good. I'll replace it soon because it's starting to affect my MPG.

75/74: Not sure why it would repeat if it was two 75s, I'm also not sure why this one is there because my brakes and my lights work fine. Although, my cruise control does not work as previously stated.

18: This is a surprise. The engine runs fine and gets good spark, not sure why this one appeared.

618: Also a surprise since my issue seems to be in 4th gear. I'm really not sure what to think of this, but Ockham's razor would suggest that this is actually 619 for a 3-4 shift error and I missed a flash on my CEL.

I would take the codes again to double check my work, but I was stupid and cleared the computer in March. I'm not sure if half of them will even be there anymore because the CEL hasn't turned on since then.

The "BOO" (Brake on/off) is triggered a lot. At some point during the testing one must press on the brake pedal to tell the computer the switch works. I forget to do that myself a lot and trip the same code. Provided your cruse turns 'off' when you tap the brake pedal and the lights function, you should be okay. (At times 2 different switches, one for lights and one for cruse)

Code 18 is interesting. One removes the SPOUT to set base timing. Might be worth locating the connector and cleaning it up with some contact spray and making sure it's a good connection.

If you have high miles (sorry, getting ready for work in the background and not reading back...) It might be worth while to change out the O2 sensor. Others will say it might be an engine problem, and it could very well be! But a decent O2 sensor can be purchased from Rock Auto pretty cheap, and they really should be changed out every 80-100k miles. That's a lot of switching for such an important little sniffer! (Be ready for a fight, O2's rarely come out of the 'bung' without a huge fight)

Others I'm sure should have ideas. Or at the very least say "Interesting..." to at least show people are reading here.

I'll be keeping an eye on this as well. Later today if I'm not burnt out from work I'll review it again. (working a full shift with a heavy head cold...not going to be a fun day)

S-

 

[adsm08]

I've been doing some research and all I've figured out is that this transmission sucks.

If the A4LD only sucked it would be worlds ahead of what it actually is.

 

[The_Epsicle]

If the A4LD only sucked it would be worlds ahead of what it actually is.

I am rapidly discovering the truth of that statement.

Code 18 is interesting. One removes the SPOUT to set base timing. Might be worth locating the connector and cleaning it up with some contact spray and making sure it's a good connection.

I'll do that once I figure out the transmission.

If you have high miles (sorry, getting ready for work in the background and not reading back...) It might be worth while to change out the O2 sensor. Others will say it might be an engine problem, and it could very well be! But a decent O2 sensor can be purchased from Rock Auto pretty cheap, and they really should be changed out every 80-100k miles. That's a lot of switching for such an important little sniffer! (Be ready for a fight, O2's rarely come out of the 'bung' without a huge fight)

I'm at about 220,000 miles. I took a look at pulling mine out and it is going to be a battle, which is why I've been procrastinating on buying a new sensor.


I've discovered that while I was in Colorado my family has been using my truck as a glorified garbage bin so I have to clean it out before I can work on it. Hopefuly this weekend I can actually start working on fixing the problem. In the meantime I have two questions:

Is there any way I can test the circuitry for the 2-3, 3-4, and TC lockup solenoids before I drop the pan? I want to test all of them just in case that 618 code wasn't a goof on my part.

Also, I've heard the solenoids are easy to access after dropping the pan but I don't know what to look for after I drop the pan. Will it be obvious where they are, or can someone describe their location for me?

 

[The_Epsicle]

I adjusted the OD band today. I went to go road test it and now I don't have reverse.... crap.

 

[The_Epsicle]

I just checked it again and I have NO GEARS. I shift it into reverse and it jerks backwards and then stops moving like I shifted it into park and it won't move. If I shift it into a forward gear it jerks forward and then acts like I shifted it into park again. My parking brake is is off and not sticking. The engine acts like its under load only when the car jerks, after that it idles normally.

EDIT: Neutral and Park still work if that's relevant.

EDIT 2: I screwed something up, I know I did. I'm operating under the assumption that I misadjusted the bands. I'm also going to drop the pan tomorrow.

 

[The_Epsicle]

I readjusted the overdrive band to 120 in lbs and backed off two turns. My torque wrench wasn't reading right so yesterday I accidentally tightened the band to something like 30 ft lbs and then backed off, new torque wrench today and no problem. I have all of my gears again and it shifts into OD without making a fuss

I'm calling the issue resolved, I have a pan gasket still so I'll drop the pan just to check up on everything. I'm also going to replace the speedometer gear and readjust the intermediate band while I'm under there. Thanks for the help, Teddybear!

 

[Tedybear]

I readjusted the overdrive band to 120 in lbs and backed off two turns. My torque wrench wasn't reading right so yesterday I accidentally tightened the band to something like 30 ft lbs and then backed off, new torque wrench today and no problem. I have all of my gears again and it shifts into OD without making a fuss

I'm calling the issue resolved, I have a pan gasket still so I'll drop the pan just to check up on everything. I'm also going to replace the speedometer gear and readjust the intermediate band while I'm under there. Thanks for the help, Teddybear!

No worries. Anytime you can avoid doing an R&R is a good day! And yeah, I've been bitten by the "crap torque" wrench several times. I recycle them into breaker bars when they roach themselves.

Have a great day!

S-