Transmission Issue 2017 MKZ 3.0 AWD

[FLA3705]

All, I am having issue with my MKZ. I had the trans, PTU and rear differntial fluid changed out at 72,000 miles (AAMCO).
I noticed drivetrain vibration at the end of 1st gear, into 2nd and 3rd until the car warms up (I live in south Florida). I took it back AAMCO to have it evaluated, and they said they could not find anything wrong.
I took it to my local mechanic who verified exaclty what I described above, and also pulled a sample of the trans fluid (I have only put 3,000 miles on the car since the fluid change), which they described as dark and has a burnt smell. They also observed some small metallic fragments in the fluid. I plan on taking it back to AAMCO to
address the fluid issue.
Has anyone experienced this transmission issue previously, and if so, is there a remedy?

 

[bbf2530]

All, I am having issue with my MKZ. I had the trans, PTU and rear differntial fluid changed out at 72,000 miles (AAMCO).
I noticed drivetrain vibration at the end of 1st gear, into 2nd and 3rd until the car warms up (I live in south Florida). I took it back AAMCO to have it evaluated, and they said they could not find anything wrong.
I took it to my local mechanic who verified exaclty what I described above, and also pulled a sample of the trans fluid (I have only put 3,000 miles on the car since the fluid change), which they described as dark and has a burnt smell. They also observed some small metallic fragments in the fluid. I plan on taking it back to AAMCO to
address the fluid issue.
Has anyone experienced this transmission issue previously, and if so, is there a remedy?

Hi FLA3705. My blind internet diagnosis: Aamco messed something up.

My rationale? According to the information provided, it seems your 2017 MKZ had no transmission issues until you had Aamco perform normal preventative maintenance and change the transmission/PTU/RDU fluids at 72,000 miles. Now, 3,000 miles later, your MKZ was experiencing “drivetrain vibration”. And you subsequently discovered the new transmission fluid is already dark, smells burnt and has small metallic fragments in it (more on that below).

So you took your vehicle back to Aamco, and they said “…they could not find anything wrong”. So you took it to your local mechanic, who takes a fluid sample and says the fluid is dark, burnt, and contains “small metallic fragments“ (something it would seem Aamco didn’t even bother to check when you brought it back).

Circumstantial evidence points to a mistake on the part of Aamco. Hopefully they will address this issue when you go back.

I’m sure others will also jump in with more advice, so keep us updated and good luck.

 

[Action]

The fluid change in that 6F (35/50/55) transaxle can not get a complete fluid change because of the design.
There is still fluid in the torque converter that does not have a drain. Plus the filter is internal to the transmission. It can not be removed unless the transmission is removed and the case is split open.

Not to say there isn't an issue that you should pursue. Just that a service (drain and refill fluids) does not remove all of the fluid.
Taking the car back and taking a test drive to demonstrate the concern would be prudent. This kind of thing would be better received during hours that the shop is less busy if possible. (Late morning. afternoon before 4pm)

As a suggestion, I would drain and refill fluids every 30,000 miles on that transmission.

Action

 

[batchman]

I had my Transmission drain & fill done at Ford a few weeks ago, at 55k miles. I wanted to be sure of the correct fluid. They reported (I think) 8 of nine quarts but the Owners manual reports (more sensible) 11qt capacity. Anyway, 8 of 11 quarts sounded OK to me.

If your fluid is seeming burnt already, I would suspect the wrong fluid was used.

Just a datapoint, take for what it's worth,
- Jeff

______________________________

 

[FLA3705]

Hi FLA3705. My blind internet diagnosis: Aamco messed something up.

My rationale? According to the information provided, it seems your 2017 MKZ had no transmission issues until you had Aamco perform normal preventative maintenance and change the transmission/PTU/RDU fluids at 72,000 miles. Now, 3,000 miles later, your MKZ was experiencing “drivetrain vibration”. And you subsequently discovered the new transmission fluid is already dark, smells burnt and has small metallic fragments in it (more on that below).

So you took your vehicle back to Aamco, and they said “…they could not find anything wrong”. So you took it to your local mechanic, who takes a fluid sample and says the fluid is dark, burnt, and contains “small metallic fragments“ (something it would seem Aamco didn’t even bother to check when you brought it back).

Circumstantial evidence points to a mistake on the part of Aamco. Hopefully they will address this issue when you go back.

I’m sure others will also jump in with more advice, so keep us updated and good luck.

Hello bbf2530,​

Thank you for your response and analysis!​

 

[FLA3705]

The fluid change in that 6F (35/50/55) transaxle can not get a complete fluid change because of the design.
There is still fluid in the torque converter that does not have a drain. Plus the filter is internal to the transmission. It can not be removed unless the transmission is removed and the case is split open.

Not to say there isn't an issue that you should pursue. Just that a service (drain and refill fluids) does not remove all of the fluid.
Taking the car back and taking a test drive to demonstrate the concern would be prudent. This kind of thing would be better received during hours that the shop is less busy if possible. (Late morning. afternoon before 4pm)

As a suggestion, I would drain and refill fluids every 30,000 miles on that transmission.

Action

Hello Action, thank you for the advise. This is a specialty transmission shop, wouldn't they use a fluid exchange machine to perform this service to complete flush the convertor also? What is your take on the metal fragments in the fluid (small amount)?

 

[FLA3705]

I had my Transmission drain & fill done at Ford a few weeks ago, at 55k miles. I wanted to be sure of the correct fluid. They reported (I think) 8 of nine quarts but the Owners manual reports (more sensible) 11qt capacity. Anyway, 8 of 11 quarts sounded OK to me.

If your fluid is seeming burnt already, I would suspect the wrong fluid was used.

Just a datapoint, take for what it's worth,
- Jeff

Jeff, thanks for that info. We discussed what fluid they will be using, and they confirmed they would be using Mercon LV. I'm heading back there in the next 2 days to address the issue with them.

 

[Action]

Hello Action, thank you for the advise. This is a specialty transmission shop, wouldn't they use a fluid exchange machine to perform this service to complete flush the convertor also? What is your take on the metal fragments in the fluid (small amount)?

My poor opinion of AAMCO does color my replies. This is based on an experience in Michigan in the 1980's. That was a long time ago in a place that is likely far from you.

Does the repair receipt state the transmission was flushed? You stated in post 1 the fluid was changed.
Does AAMCO always flush? Or do they have separate prices for flush versus drain and refill? If the latter, which did you get based on price?

Metal in the fluid .... If this was the first service and it was found in the pan, I am not that concerned. Especially if it is alloy only. This may continue in far reduced amounts after the first change. That with the dark fluid, tells me you likely did not get a flush.
Metal on a dip stick, I am concerned. Very concerned.
How did the other guy pull a sample?

Action

______________________________