Mercon LV in mercon V trans. Am I screwed???

[ChaseHedrick]

I have a 2006 Ford Explorer with a 5r55s sealed transmission. I was changing my tranny fluid because it hadn’t been done in a long time I went to autozone or to get the fluid and this guy brings out 5 quarts, looks like V to me but after I pump everything I look at the bottles and see 3 were mercon V, one was import (type Z) and one was LV. All the import and about half a quart of the LV is in the tranny. I had ran the transmission to check the fluid level and I hadn’t filled it enough but not a single gear engaged, but that’s most likely a fluid level issue. I took out that drain bolt but nothing came out I’m going to add about 5 more quarts of MV. Is having small amounts of LV gonna destroy my transmission or am I good to fill it and hope for the best

 

[redhat]

I would not worry one bit, that is such a small amount in the grand scheme of things.

 

[redhat]

Was it Castrol TransMax Multi-Vehicle Import you put in? I haven't heard of Type Z before.

 

[AutoMechanic]

Nah you are fine. That won’t hurt anything with that little bit.

 

[Blinker]

Did Ford back spec this transmission to use LV? If not, then I would change the fluid again. Ford revised their fluid specs and came to the conclusion that many transmissions cannot tolerate Mercon LV. I wouldn’t risk having any fluid in a transmission that is too thin.

 

[slacktide_bitog]

There is nothing wrong with what you did

 

[bdcardinal]

Did Ford back spec this transmission to use LV? If not, then I would change the fluid again. Ford revised their fluid specs and came to the conclusion that many transmissions cannot tolerate Mercon LV. I wouldn’t risk having any fluid in a transmission that is too thin.

Ford never back specced the 5R55N/W/S/E to LV. If it were my vehicle I would do another drain and put the correct fluid in there. Maybe bring the bottles back to Autozone and show them their mistake.

 

[ChaseHedrick]

This is the import that was put in and the LV is a Dex/Merc. I drained it again and I’m filling it back up with mercon V. I’m having auto one swap out the two bottles right now

 

[atikovi]

Avoid multi-make or universal transmission fluids. It probably won't kill your transmission but could result in unwelcome shifting characteristics.

 

[ripcord]

A pint of LV is not going to be a problem. I would just finish filling with Mercon V, drive it a bit and then do another drain and fill.

You probably know this, but just make sure that you follow the refill procedure correctly to insure that you have the right fluid level. You must have the transmission up to temperature to make sure it's the right level. Keep adding and running through the gears until you can't get any more in. Then, run it until it's good and hot and then open the fill hole and let it drain until nothing comes out. A scan tool to verify the trans temps is a good idea, here.

 

[Hall]

Ford never back specced the 5R55N/W/S/E to LV.

I was wondering about back-specs. Many fluid makers say you can use their LV fluid in older applications but not always in every single application. I thought Ford did the same with LV ATF in some vehicles as well (but again, not every one).

Maybe bring the bottles back to Autozone and show them their mistake.

Was going to say the same thing and make them give me the right stuff, even if I only had empty bottles. I'm sure their comeback would be "didn't you look at them?" to which I'd respond, "didn't you look at them?". They're just as guilty...

 

[HyundaiAbuser]

So there is a max of maybe .5 quarts of low viscosity fluid in there? The transmission holds about 11 quarts of fluid so you're sitting at roughly 4.5% fluid you don't particularly want in there. A 4 quart drain and fill will get that down to about 3% I wouldn't worry about it one bit. Chances are even if the fluid wasn't great for the transmission it probably isn't even close to any amount great enough to damage anything. The viscosity difference of that is probably akin to a couple hundred miles of driving.

 

[Infomercial]

You could do a cooler line flush.


If you only changed 5 quarts there are still 7 old quarts. You will go through less fluid to get clean fluid doing a line flush than multiple drains or pan drops. You said it had been a long time. Hopefully you changed the filter already.

You want the fluid dripping and not a steady flow to indicate it is at level when filling.