Trans "slip" in third and fourth

[MountaineerGreen]

Yes, I know there is a search! I tried but don't know the words to describe what is going on.

In third and fourth (OD) it seems almost like it slips out of lockup. Going down the road a highway speed (cruise control set), my RPM's always settle in about 1600 @ 60. Recently I have noticed that occasionally the engine RPM's flare up about 200 rpm over whatever it was running. This happens regardless of gear or speed. It goes up for a few seconds, then settles back in. All of this on flat ground. If someone can tell me if this is normal or not and what to do if it is not normal, I would appreciate it. Or you can tell me what key words to search and I will find it myself. Thanks.

EDIT: I almost forgot- I have been towing a relatively heavy camper lately, never ever in OD or more than about 60. My trans temps have maxed at about 180 on a long hill climb. My temp sender is before the inlet on my cooler.

 

[toy720]

Sounds as if your torque convertor is kicking in and out of lock up might be the Tcc solenoid.

 

[Glacier991]

I agree with Toy that the TC might be unlocking. That can also be related to other electrical concerns... speed sensors, ECT, BPP, TP, TSS and OSS and even the PCM.. and other things like pump damage, tcc solenoid (as toy mentioned) even the VB - damaged gasket, damaged sep plate... also the VB bores used in the fluid lfow to the TC can be sticky or damaged somehow (bores 200, 201, 216 - the last is the thermostat bypass valve). Fluid condition is also always a concern. lastly, your TC could be bad or headed south.

First idea... rule out ALL electrical concerns. This is a place where the trans tester is gold.

 

[MountaineerGreen]

Well, the trans fluid is less than a year old. Prior to me servicing the transmission, it had never been done. (112K) I drained the torque converter when I dropped the pan. I haven't had any issues up until this point, and this is mildly annoying. I am just concerned if this will lead to any damage.

I need my truck to pull my travel trailer. I never expected any transmission problems as I am not exceeding the max towing capacity, and the truck pulls the camper rather well. I guess I need to go to the trans shop??

 

[Glacier991]

When you said you drained the TC, I for the first time realized you had the 5.0 (in your avitar I know I was just lazy I guess). My previous advice was geared towards the 5R55E - you have the 4R70W.

Here's what the FORD book on this tranny says for TC clutch cycling - which is what I think you have...

PCM system: electrical inputs outputs. Wiring harneses, PCM module, TCC solenoid, OSS.

Hydraulic/Mechanical: Fluid condition, Main controls (Valve body) Solenoid pressure regulator valve, convertor limit pressure valve stuck, bolts out of torque specification. Solenoid screen in VB blocked or damaged, TCC solenoid damaged or not functioning properly. Gaskets damaged. Pump bolts out of speciification, gaskets damaged. Input shaft seals leaking/damaged. TC issues - excessive end clearance, nuts to flywheel loose.

That is the laundry list. I think you can fix this without a rebuild. The trans tester can tell you in a heartbeat if it is electrical or something internal to the tranny. I can set you up with a loan of one.

 

[MountaineerGreen]

What are the odds of a bad TC? Your laundry list scares me. I hope that I don't need a rebuild. Do you think you could narrow your list down to a few things that are more likely?

I may be able to get a hold of some Ford tools from my friend at the stealership. I assume a Ford dealer would have a trans tester. I can check on that tomorrow. If not, I guess we would have to ship it back and forth?

 

[Glacier991]

I'd have to say that before I would be comfortable venturing a guess I'd want to know how it operates when disconnected from the PCM and on the trans tester. A number of input issues come to my mind... like a shorting brake light switch (every time you step on the brake the TCC unlocks)... if those can be ruled out, I next would suspect a bad TCC solenoid.... but do not suggest you just throw parts at the problem.... the trans tester can also externally test the TCC for you.

Since you have a dealship connection you need the Rotunda Transmission tester with the extension cable,. and the AODE/4R70W cable (Cable C) and overlay for the ADOE/4R70W. If your friend can swing this buy him a case of beer. The tool lists for around $800 but is worth its weight in gold, like I said.

This tester plugs into the transmission in lieu of the vehicle harness and allows you to test the internal electrical components via the tester ports (a good phmeter voltmeter is needed) and also to run the transmission via controls on the tester - maunally shifting the transmission via manual inputs. You totally eliminate any computer/electrical input issues by using it. You can rule out internal problems or external input issues readily.

 

[MountaineerGreen]

If I am able to swing the tester, is the plug easily accessible or do I need to remove some parts first? I should be able to get the tester, but it may take a couple of days to access it after hours.

 

[Glacier991]

The plug is on the side of the case, easily accessible. If for any reason you cannot swing it, I have one to loan out. With appropriate refundable deposit. (Akin to Autozone's loan policy)

 

[MountaineerGreen]

Today I was driving locked out of OD, and the TC never locked in. I could actually feel it slipping. I put it in OD, it locked right up. ?????

 

[MountaineerGreen]

Ive pulled a 5000# camper a couple of hundred miles now in hilly terrain with oversized tires. Could that have caused the problem I am having? I wouldn't think that thak kind of load would be a problem for the motor trans combo. I want to fix this problem, but if it is goning to continue as long as I pull the travle trailer, I may need to find a different vehicle.

I have a 95 F150 2wd work truck with a 302 auto. I have pulled 8000 lbs plus for hundreds of miles and had no problems. It has to AOD as I understand, and it is basically the same trans as I have in my Mountaineer. Is that right?

Am I overloading my Mountaineer?

 

[Glacier991]

The 4R70W is an excellent and very strong transmission, and well suited to towing, so it isn't that the 4R70W is at fault or that there's something better out there.

 

[MountaineerGreen]

^^^ Thats what I thought when I bought my Travel Trailer, I wasn't worried a bit. Now I don't understand what is going on.

 

[toy720]

Kinda off point but the f150 has the 4r70w as well the aod went through 93

 

[toy720]

Could you not swap the solenoids from the f150 as a test That would save some money and rule some options out.

 

[toy720]

Actually if you have a 20 bolt pan on the f150 its a e40d just thought if that(sorry)

 

[MountaineerGreen]

I don't really know what pan the F150 has, but how expensive would a solenoid be? My friend dosen't even know if they have the tester, he is trying to talk me into buying an Expedition with 50k on it I dont have the cash for that kind of thing. I really hate to take it to a trans shop I don't know or trust.

Here is what I pull-

 

[MountaineerGreen]

 

[toy720]

Not sure on the cost of the solenoids but for a test you could check you f150 pan count the bolts that attach it to the tranny if it has 14 its an 4r70w if it has 20 than its an e4od as for the expedition its has the same tranny in it but your pulling a bigger vehicle in my opinion thats wont do nothing for you to get the expedition.(As far as the test take the solenoids off the f150 and put them on your explorer and see if the problem goes away.

 

[MountaineerGreen]

Thats kind of what I am thinking- the expedition had the same transmission.

Unfortunately, the work truck is at another location right now and not available for donor parts.