Well, today i had my first bout with tranny issues of any kind either before or after my BTS installation. After sitting all day at work, heading home, the shift i guess from 2-3 at about 40-50 mph shifted really hard, BANG. Heard a whirring/whining sound, lots of slipping with the TC. After a lil ways it was like it was in neutral.

Coasted to stop. Went thru the gears from park, rev, and drive about 3 times, got movement each time. Got out, looked for obvious, no fluids or linkages apparent. Drove thru town about 25-30 mph. Felt like it was "hunting" and shifted like a manual grinding gears. Got on highway and no overdrive and im thinking no high gear either.

Push button on shifter light changes, but no change in operation. Running 60 and rpms are turning 2700ish. Still "hunting". But while hunting it isnt wide rpm swings, just a small amount, not wide enough for a gear shift. Im thinking that its torque converter constantly engaging and disengaging.

While letting out of gas it coasts down with TC still locked up all the way down to about 1100 rpm before unlocking. Then i start seeing the OD light flashing. Ok, classic wire chafe in steering column. But it doesnt always flash, only sometimes. And fuses are good. Temps never got above 150 during this 50 mile drive.

So i get home (and its friggin dark already, i hate that this time of year) and i log on and start reading up on this again to refresh my memory. I had called Brian over at BTS when it happened as i was going down the road, he was busy at time. He called me after i got home and i explained and he talked me thru some things. Wanted me to pull the codes and get back with him tomorrow. I did that and the screen shot is below. I will talk more with Brian tomorrow.

But during some of my reading i think i came across some others that had similar trans codes and the issue ended up being the alternator. Alternator ? For trans issues? Is that right? I guess stranger things have happened. I have a high output alt waiting to be installed but havent yet. I guess we shall see. Brian thinks it something telling the TC and trans to act that way. Doesnt think anything mechanical, yet, leaning towards electical. Would love to hear others input.

 

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I can guarantee you that bad alternators, or rather, alternators that leak excessive AC voltage that manifests itself as electro magnetic interference... can do just that... interfere with Hall Effect sensors, of which the transmission's Output Speed Shaft sensor and the Turbine Speed Shaft sensor (ie, your codes) are among. This errant AC voltage EMI from the alternator can cause these magnetic sensors to lose their way. Without the proper data from the sensors, the transmission doesn't know how to behave, which can in turn can cause more transmission troubles... leading to hard part failures.

I have experienced the relationship between failing alternators and transmission trouble twice now. This doesn't necessarily mean that your case is the same, or even similar, to my experience, and therefore these comments should not be interpreted as any type of remote diagnosis of the trouble codes you presented. It is just to say that it is not outside the realm of possibllity at all for leaky alternators to cause problems with a magnetic Hall Effect sensor.

I happen to think that a some of the CPS issues that people have may very well also be due to failing alternators. The CPS is a hall effect sensor, just like the transmission's OSS and TSS. And we all know that the OEM 110amp alternators are underbuilt for the demands they are tasked with, and fail fairly frequently. There are six to eight diodes in an OEM design alternator, depending on the specific model. If just one diode goes bad, then that diodes ability to rectify AC into DC is compromised, leading to some AC leakage beyond a tenth of a volt.

 

Anyone know how easy or difficult it is to change these turbine speed sensors? Diagrams that ive found show them to be towards the top side of the trans. Does the trans have to be dropped to change?

 

What makes you think that changing the sensor will fix the problem? If the root cause of the problem is EMI, a new sensor won't fix that, but might be able to mask the symptoms longer. The TSS is on top of the transmission case, in the forward half. The OSS is on top of the transmission too, but at the rear half.

 

JUst thinking out loud and trying to gather information. I likely wont get a chance to do anything until either the weekend if im lucky, or next weekend if im unlucky. Just trying to get lil knowledge before hand just in case. I fully understand that sometimes causes are masked by other symptoms, but the code indicates sensor or circuit issues? No? Was just thinking where/what/when i could tackle the job of either changing sensor, checking connections, look for wire chafe, or something else. I had read something that it may be on top of the trans and was wanting to confirm with someone who had actually done it. If that is it, will trans need to be dropped or is accessible as is? The more info the better.

 

Understood. Connectors to the sensors on top are reachable (with long skinny arms) without dropping the trans. but I have not actually replaced my sensors, because in my case, I was able to diagnose the cause as being the alternator. Once I removed the offending alternator from the equation, the transmission operation returned to normal, the flashing TCIL stopped, and the codes went away. This might be a potential diagnostic option for you, if you can borrow the alternator out of your dad's similar truck.

 

I have another alternator that i keep for a spare on hand, and i have a brand new Nations Starter Ford 6G 160amp that i have yet to install. I guess that would be about the easiest thing to try first.

 

I just checked the Factory service manual, and for that TSS on top at the front of the transmission, you might have to loosen the two nuts to the transmission mounting pad at the rear of the transmission, that sits on top of the crossmember that supports the transmission tail housing.

You don't have to remove the crossmember, but you might have to carefully raise the transmission up just enough to wrestle the mounting pad off of the crossmember, so that you can then lower the transmission tail housing down to the crossmember, such that it occupies the same space that the mount vacated. That lowering will afford enough space to withdraw the body of the TSS out of the top of the transmission.

In otherwords, while the TSS connector can be reached and unplugged with skinny and long enough arms/fingers... the actual withdrawal of the magnetic sensor, which extends down into the trans, may require a bit more headroom between the trans tunnel and the top of the trans. Ford's service solution is the removal of the rear mount, combined with a small amplitude of raising and then lowering the transmission enough to pull the sensor out.

Ford cautions against raising the transmission too high and crushing the OSS sensor connector against the floorpan. Before I did any of this, I would follow the diagnostic tree sequence for the codes discovered. And before that, I'd probably try the alternator.

 

In regards to "leaky alternators" was it leaking AC ripple down the DC line. did it affect just the transmission? In my RV work, I pick that up in multiple systems with module boards. Just curious. I would have anticipated problems with other systems.

Steve

Steve

 

Call me old school, but anytime something goes Bang, Clank or crunch, It's screaming somethings broke in the box...... I would be sweating over the TC, or the Trans internals......just sayin,....

 

Well, when im able to start working on it tomorrow morning I think im going to have the following plan of attack given suggestions made here and what ive read elsewhere. Start with an alternator swap, thats easy enough of a starting point. Then if that doesnt work going to check the chasis grounds. Had my mech that did injector work earlier this year mention he thought they looked in poor condition. Then if that doesnt work then im going to tear into steering column and inspect for wire chafing there to rule that out. Then next if unsuccessful will get under the truck and inspect wiring, connections, sensor and see what results that can be found there. If not that ill have to go back to the drawing board. But i must say that im a bit disappointed in BTS at the moment. When it happened and i made my first call he called me back within two hours and asked for the codes. I emailed the codes and called daily to talk to him but have as yet to get a call back and apparently doesnt work on fridays. So i guess ill have to go it alone this weekend without input from the trans guru....

 

If the you have fully charged batteries and the problem is constant, you really don't have to pull the alternator. Simply disconnect it and run your truck on the batteries. There is not way they can produce an AC ripple to disrupt your modules, so if all it well running with no alternator swap it out. Obviously you can't do this for long, but if it happens all the time, you should know immediately.

Steve

 

And therein lies the trouble with an otherwise good idea. When I experienced transmission faults that were eventually traced to EMI, the symptoms DIDN'T happen all the time, and it wasn't possible to tell immediately if the transmission was behaving. I could start it up, and it would act just fine for two miles down the road, and then feel a hiccup.

I've driven the truck on batteries alone, with no serpentine belt connected, so I know that it is possible, even though in my case it was involuntary. With no power brakes and no power steering, you know you've driven something when you get it safely back home. It just isn't safe to drive around a community on batteries alone, hoping that the fault will show up, and then suddenly a neighborhood kid darts into the street out of no where chasing his soccer ball.

On a farm, private property, ok. And like you say, if the fault happens all the time, ok. But the trouble is, some faults don't happen all the time, even though the evidence of their happening sets codes in memory.

 

Well, i will try that in the morning as well. I live in a rural area with lots of open pasture and farm land so i would feel comfortable doing that. Batteries are only 3 mth old and have no reason to suspect not fully charged, but when ive had a bad alternator in the past ive learned that you can drive quite a ways on just the batteries in these trucks. And yes, so far it happens all the time. Ive driven about 150ish miles or so since it happened and it has behaved this way consistently for this time. I need to fix it, motorcycle rides in the morning to work are getting kind of chilly nowadays.