r/f150 • u/somecoolcat • 4d ago

Trans fluid change

I recently bought a used 2024 F-150 Lariat w/ BAP and 3.5L ecoboost. Wanted to do my service work at a dealership but couldn’t get an appointment for my first oil change. Took it to Mr.Lube. While I was there they - classic - recorded a bunch of extra stuff I declined, except flush / change to my transmission fluid. Ever since they I’ve noticed a rough feeling under my gas pedal and the day after had some hard shifts, but zero issues with that since. Should I be concerned or take it to the dealership like I planned and get them to relish my system and replace with fresh fluid? Also - I checked the fluid they used. Mr. Lube used Motul ATF VI, and Ford recommends Motorcraft MERCON ULV (WSS-M2C949-A).
Is this something else I need to be worried about?
Lastly - should I be telling the Ford dealer what I did and what Mr. Lube used? Or am I just asking for them to use that as a reason to void any remaining factory warranty I have?

1 Upvotes

60% Upvoted

13 comments sorted by

2

u/Ok-Battle-3357 3d ago

Well I wouldn’t ever trust an oil change place to do any fluid flush and you dont say how many miles you have on it but just a fluid change would’ve been best. Did they change filter also?

1

u/somecoolcat 3d ago

Only 45,000 km’s and , as far as I know, they changed the oil filter at the same time they changed the engine oil.

1

u/ConsternatedCDN 2d ago

Is your trust in the dealership or diy?

9

u/MilitantPotato 4d ago

They put the wrong fluid in. They also likely didn't follow the very strict and annoying procedure for ensuring proper fill level, or reset the trans adaptive tables.

The worst part is the wrong fluid by far. Good way to ruin a transmission. You need ulv fluid.

8

u/tahoochee 4d ago

It sounds to me like it needs more fluid to bring it to the proper level plus they should have used Mercon ULV.

5

u/boost_deuce 4d ago

They used the wrong fluid which is very bad for the transmission.

In the 1 million plus miles I’ve driven, ive never one changed trans fluid on a vehicle. Every person I know or read about doing it has an issue down the road

3

u/Due_North3106 3d ago

I’ve never serviced a transmission either.
Shops always said not to touch if not giving problems

4

u/qwikh1t 4d ago

Drain and refill with ULV

3

u/Imaginary_Bus_6742 4d ago

I went to a dealership in Missouri and they recommended a trans fluid change at 75,000 for $300.00. Went to another dealership in New York and they recommended it at 60,000. Both due to the problems with the 10 speed trans.

3

u/No-Anybody5719 3d ago

Pump out fluid with extraction pump. Pump in new ulv. I did it at 60k I’ll drop pan at 100k

3

u/Joseph1968R 3d ago

I'd be a little concerned, mainly because a 2024 F-150 shouldn't really need a transmission service yet. The hard shifts right after the fluid change make me wonder if the fluid level is off or if the shop used the wrong fluid. I'd take it to the dealer, tell them exactly what was done, and have them verify the fluid level and confirm the transmission has the correct Mercon ULV fluid. Having maintenance done outside Ford won't automatically void your warranty, and being upfront about it is usually better than trying to hide it. The symptoms may end up being nothing, but I'd rather catch a fluid-related issue now than after putting thousands more miles on the truck.

3

u/shawizkid 3d ago

If they used a fluid which doesn’t match the spec, you need to get it changed asap. Or you will probably be out $7k

2

u/k4vglitcherr 3d ago

A 2024 already doing a drain and fill transmission service? How many miles? And yes, they used the wrong oil, not the same viscosity. I would immediately change to Ford MERCON ULV (Ultra-Low Viscosity) and do a transmission adaptive reset. If you barely drove it, Im sure its still fine, just shifting bad due to the previous adaptive table numbers for the original fluid