04 Ranger 5R55 problems after rebuild

[-reverb-]

Hi,

I recently purchased a 04 Ranger with the 3.0 with 180K miles. The trans is a 5R55 - not sure of the suffix. After driving a week or so, I started to feel the trans jump out of OD to lower gears under very light pedal. This usually happened at around town at ~40 mph or so. The tach would jump from 1500 to around 2300 and then quickly would settle back down and shift back into OD. It doesn't do this all the time, in fact most times it is fine. As far as the shifts themselves, they are smooth and consistent. In other words, when it is not showing it's butt, the trans is silky smooth. I figured a sensor or something was acting up.

I took it to a very reputable local trans shop for diagnosis. The told me there were brass shavings in the pan and it needed a rebuild. Upon return I was told the OD planetary had problems and they changed that and did a full rebuild - all wear parts replaced.

Took it home and a day or two later, it started doing the same thing - jumping out of OD then settling back in.

Took it back to the trans shop and they said "must be a pressure drop in the valve body". Worked the VB for a couple of days only to find there was not problem in there. Next idea was that the Power Control Module needed replacing. They changed the PCM and I picked-up the truck. All this work was done as warranty repair - didn't cost me any extra.

Now after a few days back with the truck, it's doing the same thing still - jumping our of OD and the quickly settling back in to OD.

To me, it's like the trans getting a bad signal from a faulty sensor, loose connection, broke wire or something. Given that it acts normal most of the time and the shifts are so smooth, I have a hard time believing there is a problem with the mechanical aspect of the trans.

I know this is a lengthy first post and I appreciate anyone's wisdom and advice on this matter. Quite frankly I am tired of dealing with this guy at the trans shop. His work is top-notch according to reviews but I just don't like his attitude towards me as a customer. He gives me the impression that he is "doing me a favor" by fixing a transmission that I paid him to fix!

Anything I can test/look at/swap-out that may solve this issue?

Thanks!

 

[Kevery]

Maybe the abs/speed sensor in the rear diff. They are cheap and easy to replace.

 

[JK080]

The good way to catch this kind of issue is to have a scanner that is capable of showing and recording the data stream, so when it acts up you can go back to that moment and check all the inputs and outputs of the computer to see if anything is out of line.

That shop should have this capability, but it seems like things might be getting touchy with them. They should fix this problem without any fuss, you are the customer and you paid them to fix it, bottom line, it's now their problem. Its best to try to keep this civil because nothing goes right when everybody is all upset, but do what you have to do.

I am not familiar with that problem with that transmission, and didn't find anything in my database with a similar complaint so I don't have anything else to check at this point.

Good Luck.

 

[-reverb-]

Thanks for the reply JK080 and Kevery.

Kevery:
I haven't noticed the speed-o getting funky when the trans goes into it's gyrations. After reading about bad Vehicle Speed Sensors, I would maybe expect that to happen too. I'll keep an eye out. Your point is well taken however, it's about a$12 part so why not change it out and see? May get lucky!

JK080:
I am not sure the shop has the capability to record data. Seems like this would be the way to go instead of throwing parts at the problem in hopes of fixing it like was done the second trip in the shop. They did tell me when I took it back that they needed to see if the trans was switching on it's own or was it being commanded to switch. That would indicate the have SOME type of visibility into the electronic aspect of things.

As for being civil, I agree and that's the way my parents raised me. I have tried my best to be respectful and courteous to the owner. I am losing patience however given the way he treats me and my wife when we have to deal with him. He has never called (as he promises he will) to give status - I have always been forced to call him. Also, the first time it was in for repair, they had it 20 days. The second time, it was there for 11 more days. I have made 2 payments on the vehicle while it has sat in his shop. Just poor, poor customer relation skills. I would more willing to overlook all that if the work was performed correctly.

Again, thanks for your inputs!

 

[FR-425]

Just a thought.

The light acceleration is the clue I'm grabbed by.

I think you do not have a transmission related issue causing this but rather a dead spot in the Throttle Position Sensor. (TPS)

I think what you are experiencing is not Overdrive but TCC (Torque converter clutch) unlocking under light acceleration.

When you move the throttle suddenly either way the TCC is supposed to unlock.

If you have a "noisy" spot in the TPS, the PCM gets a sudden voltage change which ques it to unlock the TCC.

Happened to me and a $50 TPS fix it up.

Note: this will not produce a CEL

 

[PopRichie77]

A bad output shaft speed sensor would cause other problems also so I wouldn't think that was the problem, I would also lean towards a bad TPS sensor, if it were mine that's what I would check, but could be something else.

 

[-reverb-]

Well, it's going back to the shop for the third time. Will let you know what, if anything, I find out once it is returned to me.

Actually, the shop owner was sort-of nice to me this time when I talked to him. That was a nice surprise.

 

[-reverb-]

I think we finally have a resolution. I got the truck back about a week ago and everything seems to work as it should. I haven't experienced any issue with the trans jumping out of OD.

I don't know exactly what was done but the shop owner told that they called Ford and asked their opinion - they were somewhat stumped. Ford recommended that a ground strap be installed somewhere on the transmission - I assume supplying a ground for the transmission that it would normally receive through the wiring harness. In essence provided the trans with an alternate grounding path. Ford speculated that for some reason, the trans was sporadically losing the ground signal and that was what caused it to gyrate in and out of OD. I'm not sure where the new ground was added but somethihng about the the torque converter was mentioned when it was being explained to me.

I am not sure if this makes sense or not. I still don't understand why it only exhibited problems under light acceleration. I am not complaining however. I have the truck back and it seems to shift correctly!

Thanks for all you comments and suggestions.