Your wrong Mark, Here at Ford we call it Meron III because of it being both Meron and Dextron III rated. So he isn't wrong by calling Merc3 like us here at Ford.

 

Your right about the rating. I am looking at a bottle of Castrol ATF and it says it meets Mercon/Dextron III specs.

Funny thing is in the Haynes manual for 99'-04' SD they tell you NOT to use Mercon V. But now Ford tells you its ok to use Mercon V. Sounds fishy to me.

The manual says you are not supposed to mix Mercon with Mercon V.

The guys tranny problem is definatly mechancial and not caused by the fluid.

 

I can call an apple a red orange and i guess i wouldnt be wrong either - hey they are both fruits right?



based on my experience Mercon and dextron III have always been the same rating, this is the first i ever heard of anybody calling mercon by "mercon III" in my life. If you work at ford and told me you were going to put mercon III in my tranny i would find business elsewhere - just being honest here... theres not a company out there that i know of that makes "mercon III"


as for the guy with the problem - i would not put any magical additaves in the tranny either - let the problem be fixed, dont add stuff to the problem.

kenny

 

Nice write up, but I'd be very concerned about letting your trans pump fluid out until you see air bubbles. That means that your pump is running dry, that can't be good. I once worked for a lube center and we flushed a trans by matching the incoming to the outgoing. I would check the level of the trans as it's pumping fluid out and add a quart or two as it gets a quart or two low. I just don't think it can be good for the pump to let it run dry.

 

i have flushed my tranny like that and never had a problem - its not like you are letting it pump dry for hours on end, it pumps dry for maybe 2 secs at most. You are supposed to do it with two people when you see an air bubble you have the person in the driver seat kill the engine.

While you are doing the pump out the guy in the driver seat is supposed to be cycling the gear shift

kenny

 

Have you ever tried to do this? The trans will pump out 4 quarts a minute. Can you pour fluid down that little dipstick tube that fast? I can't.

If you read the instructions I wrote to shut the engine off as soon as you see the large air bubble. That's when the pump runs out of fluid. How would it get dry? Dry means no fluid. There's fluid clinging to everything, as long as you shut the engine off promptly there is no chance of damaging anything.

But if you don't trust it, don't do it.

 

Taking it kinda personal huh?? Did you miss the part where I said nice writeup?? Maybe it's just me but, when a pump runs out of fluid isn't it by definition...dry??? Maybe instead of waiting until you see bubble shut it down when it's a few quarts low. All I'm suggesting is that there may be a way to avoid "letting the pump run out of fluid", possibly saving yourself a situation where you could cause damage. Is there something wrong with that????

 

i didnt even know mark wrote the article, but i back it up 100% cause ive done it and never had an issue.

Do you think these "pumps" in the trannies are primed when they first build a truck - I sure dont think so

kenny

 

I think it's you. I don't see it dry, there's still fluid there, but not enough to pump. Still, it's not good to let it run like that for a long time. There isn't a lot of fluid left once the air is seen.

 

Please help me understand this. I have never done this before. In order to see air, does the pump pump air to flush the lines and cooler? Or does it just stop coming out of the hose once the pump pumps all the fluid it can?

Thanks

 

to get all the old fluid out expect to use about 4 quarts of waste (my opinion)

but theres no need to do a wastefull flush like that, just let it pump till air twice and you should be fine

kenny

 

Yes, no body in their right mind installs a Torque Converter without filling it first, that's where the pump gets it's prime from...within seconds.

You can argue with me all you want, no person in their right mind will tell you that it's you're better off waiting to see air bubbles than you would be stopping before the air bubbles and topping it off. Do you have any clue how disasterous it can be to let a torque converter run empty???

 

im not going to sit here and argue with you, but i will say do you honestly think all trucks built have fluid put into the torque convertor. Do you really trust the manufacteres that much? The more i live life the more i trust no-one but myself.

I will also agree that it is better to stop the flow of fluid before "bubbles" but i will also like to say that I have run my pump in my tranny to the "bubble" point many times and never had a problem. I had my line disconnected right BEFORE the tranny cooler.

I am not saying it is better or worse i am saying it is a heck a lot easier to run the pump till you see a decrease in flow / air. Rather then "guess" at how much fluid was changed.

The question now becomes would you rather change more fluid with the risk of getting an air bubble... or would you rather change almost all the fluid and have the old fluid still in there, or waste extra fluid doing it your way?

Theres nothing wrong at all with pumping and guessing at the amount of fluid but i will say it will be a lot more expensive if you are trying to get all the old fluid out.

When I had my tranny pan off and replaced the filter it has a huge suction nose on it (the filter) I assume it is what does the sucking out of the sump - and where is the pump located? Unless it is located in the torque convertor then it must be able to run dry at least for short periods of time.

Nobody is arguing what is better or not, just what is easier.

People abuse these trucks all the time, do you really think running a pump dry for < 1 - 2 secs is going to damage stuff?



You seem to know more about the mechanics of the sump and tranny pump, so I am coruious where is the pump on the 4R100 tranny located?


by the way i honestly dont think the torque convertor is going to run "empty" - i remember on mine just seeing fluid flow slow way down not like a bunch of air started flying out.

I just agree that the article is an easy way for somebody to do it at home so long as there are two people there.

If you want to make up an article that shows the "better" way to do it where nothing runs "dry" even not for 2 seconds then by all means go for it, time your truck and figure out the fluid flow, then add in an offset for the possibility that somebody elses truck may idle faster or slower and take longer or slower. Also factor in different sump sizes - I think you will see - its not so easy to write up a article that suits everybodys needs.


thanks, Kenny

 

It's your truck do as you please. It's a lot easier to do what I'm saying than you think. BTW, the pump is the part that the Torque converter slides into and engages.

 

I took mine to my buds repair shop and hey power flushed it and it works great for $120 money well spent