1999 E250 4.2 V6 177k

Getting a bit of slippage -- today - first time adding ATF, I added 1/2 qt Shell Mercon / Dextron.

Existing fluid is red and smells good - not burnt.

The dipstick says use Mercon V

I'm going to do some kind of service either machine flush or just pan removal, filter gasket --- (I may do that)

Do I need to go back with V if I do the pan - filter ?

What about a machine flush - how do I know that the bulk fluid is the correct type at the service center ?

Of course I'm concerned about my high mileage and the trans dropping dead upon fluid change ???

 

I know that Motorcraft no longer makes Mercon (non V) so that's all you can get from a Ford dealer.

If you go to a non-dealer service place, you could ask them what they use, or look at labels on the bottles or drums of fluid they use. If they are "not sure" or tell you "all trans fluids are the same", I would choose a different service place. It's kind of like asking a doctor what blood type he's using for your transfusion. If he's not sure, it's not a good sign...

If the trans is slipping, it may be on its way out anyway, so don't count on a fluid change solving all your issues.

Good luck,
George

 

This is how the urban myth that a fluid change kills transmissions keeps going and going and going....

The trans has a problem, so change the fluid. If the trans is really slipping (and I doubt that it is) then new fluid isn't going to help, but on the other hand it won't hurt, either. If it is really slipping it's about to die. New fluid won't stop that, but when it does die the new fluid will take the blame.

If you do change the fluid you will have problems if you use anything other than MERCON V. You can use any brand you like, but it must meet MERCON V standards or the trans will be very unhappy.

 

DO NOT do a flush unless you want to kill your transmission. Fluid and filter change is okay.

 

A flush WILL NOT damage the transmission. That's an old wive's tale, and I explained why right above this.

Changing the filter is a waste of money. If the filter needs to be changed it is because the trans is junk.

 

Kovalsky- am I correct about this?
Transmissions may slip due to low fluid, but not due to bad fluid.
Also, if you feel your transmission slipping, you should IMMEDIATELY stop driving it to avoid further damage. It only takes a few seconds of slipping to cause irreversible damage to clutches/bands.

 

Low fluid or bad fluid can make a transmission slip. It does only take a few seconds of slipping (less than 5) to destroy a clutch or band.

 

Last night like I said I added about half - three - quarters quart of Shell Mercon.

Drove today --- no slip - that second or two rolling through a stop sign. All's tight, no clunk and seems improved.

I did see the V rated at the AP stores online if I need it. Since the fluid is red and not burnt, I'm going to leave it be.

Thanks a lot for the edu.

 

Sorry, but I have heard from too many people that the transmission on their older vehicle failed after a flush to consider it a wife's tale. I read it has to do with the debris being dislodged and going into places it shouldn't which causes the failures.

 

I value the input of Mark, who is a transmission engineer, over anecdotal accounts of failures which are probably results of an already-failing transmission giving up the ghost after a "last ditch" attempt to fix it by flushing.

If the flush was done reversing the direction of the fluid flow (blowing all the debris in the trans pan backward thru the transmission) this theory might make sense, but flushing machines simply splice into a cooler line and substitute new fluid for old fluid, and flowing in the same direction. If the flushing machine has contaminants in IT (trans fluid Ebola virus), or if the wrong fluid is used, that could cause problems. And frankly, I might not trust a random "quick oil change" place to use a good machine with good filters, and to use the right fluid.

If you have an older engine, would changing the oil cause it to fail where it would not fail with old oil? Again, if the oil change blew oil backwards thru the engine and blew the contents of the filter back thru the passages, this might be plausible, but that ain't what happens. I have heard stories about full syn oil clearing out sludge that is helping seal a bad gasket (kind of like bars leaks for oil) and causing seepage, and "maybe* this could happen on an engine that has been run on sludge for its whole life.

I'll go with Mark. I'm a fan of science and logic over hearsay. And thanks as always for your presence and valuable participation in trans questions, Mark.

George

 

Yeah I'm with Kovalsky too...

Very well stated regarding fluid flowing backwards or forwards. Great point.

Also good point that transmission flushes are often overlooked maintenance- until it's too late. Someone gets it done upon experiencing symptoms.- too late. It's like changing your oil because the dash pressure indicates low.

And even considering the possibility of the anecdotal evidence: it's based on the new fluid knocking loose the gunk and causing problems (how was that worded..?). The point is that the gunk shouldn't be there. IT is the problem.

My favorite point is about shops using crappy machines or especially using wrong fluid.

I guess everyone else already made my points... Oh well...

A big question is for guys like me- 167,000 miles on a V10 E350, with zero transmission maintenance since buying it 50,000 miles ago, and unknown transmission maintenance before that... I feel like I am a candidate for the ol' Tranny Flush Causing Problems argument.

 

My only contribution here is anyone ANYONE arguing with Mark on Ford transmissions is on a fools errand, plain and simple.

I wouldn't disagree with Tom Edison about light bulbs or the Wright brothers about aviation so it follows I'll let Mark's experience speak for itself.

The newest members here tend to not know his pedigree or experience which is the reason we have the occasional questioning of his contributions here. Good thing he's patient because if I possessed his knowledge I'd have long ago said adios amigos----hasta la vista babitos!

 

I'd flush that thing ASAP!

 

I've heard them too, and I don't believe that the whole story is being told. Let me use an analogy.

Someone gets a new car and is convinced that since oil never wears out, changing engine oil is waste of money. I've known people that believe this and have followed this logic.

After 30,000 miles or so the engine develops a rod knock because it spun a rod bearing due to failed lubrication. Now they change the oil, but 20 miles down the road it throws the rod through the block.

Now what caused the failure? Not changing the oil for 30,000 miles, or the new oil that was put in 20 miles ago? This is the same thing as never changing the trans fluid until a problem shows up, and then blaming the new fluid for the failure.

 

Can the the oil to water cooler be flushed effectively to meet warranty requirements on a Ford reman unit? Service info states the external cooler needs to be replaced when installing a new or rebuilt unit. Any thoughts while on the subject of flushing?