5r55s Double engagement or harsh reverse

[Littleant]

Hi folks. Question on my 2010 mountaineer 4.0 with 65,600 miles AWD and the 5r55s trans. When cold trans is fine. When warm about 10% of the time when shifting into reverse there will be a lite engagement then a second engagement into reverse. sometimes the engagement is a little harsh. No lights no codes no issue in any forward gear with smooth engagement. No OD issues. Trans fluid changed every 20,000 miles with filter. I do all the service work. 90% of the time works great. Thank you.

 

[JK080]

Hard to say, it could be a number of things that could cause this.

In reverse the direct drum and the reverse band are applied, the double bump is usually one component coming on before the other most likely caused by a leak in one of the hydraulic circuits or a control issue like a valve or solenoid. Basic checks like the manual linkage adjustments and fluid level is where to start, also make sure MLPS switch and the MAF sensor are clean and functioning.

Before moving on to the valve body, solenoid block and possibly even a internal repair you may want to wait and see if it gets any worse before continuing.

 

[Littleant]

Thank you James. I will follow your instructions. I would also like to say I have been reading the transmission forum and the information you give is priceless. If someone with an issue with their trans and went to the dealer they would be paying for the info you give. ( I believe most on this forum know that). I opened my repair shop in the late sixty's (I am 64) when cars made sense and transmissions were pretty simple. Today with these complex horseless carriages they make it's mind numbing. Again thank you sir for responding.

 

[ahuggins6]

Thank you James. I will follow your instructions. I would also like to say I have been reading the transmission forum and the information you give is priceless. If someone with an issue with their trans and went to the dealer they would be paying for the info you give. ( I believe most on this forum know that). I opened my repair shop in the late sixty's (I am 64) when cars made sense and transmissions were pretty simple. Today with these complex horseless carriages they make it's mind numbing. Again thank you sir for responding.

Can you update us on what you found on this issue? I'm fighting a transmission with pretty much the same story you gave.

 

[Littleant]

Can you update us on what you found on this issue? I'm fighting a transmission with pretty much the same story you gave.

Still the same after the first post. Does not happen all the time. Have 77,000 now. All forward gears are silky smooth.

 

[Littleant]

Still the same after the first post. Does not happen all the time. Have 77,000 now. All forward gears are silky smooth. Has not gotten worse.

 

[ahuggins6]

OK. I feel like its something sticky in the valve body. I hate valve bodies but I guess they're a necessary evil.

 

[transman304]

If you drop the VB you may look at the areas of #12 and #13 closely for sticking or broken spring. Also check #15-A boost valve for smooth operation.
Brad

 

[Littleant]

If you drop the VB you may look at the areas of #12 and #13 closely for sticking or broken spring. Also check #15-A boost valve for smooth operation.
Brad

View attachment 329042

Thanks Brad. You transmission folks are a huge asset to the forum. Thanks for the image. Will check this summer. May also change the selinoid block (motorcraft) just in case. Funny thing is this trans is the smoothest transmission I have ever driven except for the occasional reverse harsh engagement.

 

[transman304]

You’re welcome, another thing that might be a factor is the MLPS (neural safety switch) you will need to have the proper scanner and software to be able to monitor its function.
Brad

 

[Littleant]

You’re welcome, another thing that might be a factor is the MLPS (neural safety switch) you will need to have the proper scanner and software to be able to monitor its function.
Brad

Brad can you recommend a reasonable price scanner. Thank you

 

[transman304]

Maybe someone here will chime in on what would do work as far as apps go for Bluetooth readers. I’m not up to date on these types of test equipment. I only use OEM scanners and software but hear that some phone applications have really stepped up to offering some very useful data. Look for something that will let you live stream data and monitor several sensors.
Brad

 

[Littleant]

Maybe someone here will chime in on what would do work as far as apps go for Bluetooth readers. I’m not up to date on these types of test equipment. I only use OEM scanners and software but hear that some phone applications have really stepped up to offering some very useful data. Look for something that will let you live stream data and monitor several sensors.
Brad

Thanks Brad

 

[ahuggins6]

I have the BlueDriver and it reads the Solenoid C Stuck closed code and is able to clear it. I assume if there was a MLPS issue, it would give a code for that also.