Tranny "Noise" going from P to R/D

[plasma_nut]

Hi,
My Explorer has recently started to have a noise similar to "rocks flying around" inside the transmission when shifting from Park to either Reverse or Drive when holding the brake. Noise disappears when vehicle speeds up. Sometimes comes back when stopped. Shifts as smooth as ever. I did the valve body 2-3 flare fix 35K miles ago.

Read something about "Limp" mode might cause EPC solenoid to allow high pressures causing mechanical type noises similar to what I'm hearing. No OBDII codes.

Any ideas or thoughts on what to do next? I'm due for filter/fluid, would dropping the pan reveal anything?

Thanks


99' Explorer, 115K, SOHC 4.0, 5R55E tranny.

 

[PopRichie77]

I had a similar noise, it turned out to be the trans heat shield was vibrating and hitting the exhaust pipe. Also check the exhaust pipe heat shields for being loose on one end.

 

[drdoom]

I had a heck of a racket, when warmed up. It would sound fine when you start up, but for instance when you are at the drive up teller, what a racket, like catalytic converter coming apart, or the torque converter, or a symphony of heat shields rattling! It took me quite a while to find the source...I was under there tapping on this shield, that bracket, took temp measurements of the cats, you name it. Finally one day I was going to shell out for new cats, you know when you listen it sounded like that was right where it was coming from. But then I thought maybe I should be more diligent in my diagnosis. So I used a shade tree stethoscope, narrowed it down to the upper serpentine drive region, and it got the temperature up good too, and dam it was the idler pulley, ONLY squeaking when warmed up the thermal expansion would then open the tolerance and woohoo what a racket. Fixed it for 14 bucks in the lot of the auto parts store in about 5 minutes.

And as PopRichie said, the heat shield rattling is common, google that one, for instance you will find TSB for clamps or something that stop the shield from rattling.

Hey have you changed the fluid since your VB work? I mean it could be something serious, you could easily drop the transmission pan to have a peak, and pop a new filtro in there while you're at it.

Oh, I assume you know the codes for your transmission cannot be read by the run-of-the-mill scanners.

 

[plasma_nut]

Thanks for the suggestions to look for other sources. I looked hard for those other sources of sound as you guys suggest. Heat shield on tranny was solidly attached and the fact that I could make the noise appear when going from park to any gear and go away when back to park still is pointing me to the tranny. Here's what I did to get an initial read. Took to "reputable" auto repair shop in town. They're positive it's a mechanical failure in the transmission and want to replace it with a used transmission for $1200 P/L. Forgot to ask if they read the DTC codes, shoot. They also found I need new rear pinion bearings which I already knew were on their way out.

On the way home, the sound is pretty much gone. Can't figure out that one. Well, thought I'd drop the pan to see if the "mechanical failure" has left any debris in the pan. Nope, fine metal shavings on the magnet but otherwise same as other times I've dropped it. Put in new filter and flushed with 16 qts of Mercon V. Go for a test drive and all seems fine, no sound (outside of noise from the rear end that's been present for a while). Since their remedy is a transmission replacement anyway, I don't see a rush to replace my tranny with another used tranny until things get worse.

Out of curiosity, what is the cheapest code reader that can read these special transmission codes? I've googled posts and seen mention of something for about $3000 that can also actuate various components for diagnosis. Is something like that the only option? Thanks..

 

[PopRichie77]

You didn't say if the OD light was flashing? With a lot of noise coming from the trans, there should be a problem of not shifting correctly. If it shifts correctly and the OD light doesn't flash, it is very hard to believe that the noise is coming from the trans.
Trans problems don't just go away but vibrations problems do. The trans heat shield can be solid but make sure the back corner is not touching the pipe, I actually had to cut the corner off to get rid of the noise, which only happened when idling sometimes. Did you try to lift the pipe heat shields? One end still fastened will hold them down rather tight but engine vibration will cause the loose end to make a lot of noise.

You could have a cracked flex plate which can only be found by removing the trans,

 

[plasma_nut]

Yes, OD/off light does (sometimes) flash after about 10 minutes of driving. Thought it had went away after the flush, but came back after a drive today. On a positive note, still no noise after the filter change & flush though. Shifting as smooth as ever.

With my basic code scanner, I get "No DTC codes stored" when pulling codes with engine running and OD/off light is flashing. If I then choose to erase codes, the light stops flashing. Shouldn't there at least be a P07## code that my scanner could read?

 

[drdoom]

Most basic scanners will not read Ford transmission codes. I have an Actron, and it will not read airbag, ABS, or transmission codes.

But it will read Honda transmission codes...go figure.

 

[plasma_nut]

OK, an update on this. Been driving for a week after tranny fluid/filter change and the noise is still gone that I first reported above. However, the OD/off light blinks (sometimes) after ~ 10 minutes of driving. Borrowed a higher end scanner from a buddy and pulled code "P0741 - TCC System Performance. Torque converter slip is greater than expected"

Been reading like mad on this, and seems it could be a multitude of things, from as simple as speed sensor to major as torque converter. Based on the fact I put in a rebuilt VB ~35k ago with updated separator plate and solenoids to fix 2-3 flare, I don't feel I should start there. What do you guys think I should tackle first to try and track this down?

Thanks.

 

[drdoom]

I would have a look at the torque converter.