I have a quick question. I did a search but couldnt quite find the info I wanted. Ok I want to switch to Mobil 1 Synth. in my transmission which way is better just pull the pan and the plug from the converter and let it drain or use the tranny flush machine that tee's into the trans cooler lines. The machine would be faster but I think the fluids would mix is this wise? I know its not MerconV so I am not that worried. Just Curious any help is apperciated.

Greg

 

Suggestion..... don't do it! Use Mercon III only.

Some will say it's OK, but I would suggest use what Ford recommends.

 

Is this for your truck or your wifes?

Spike

 

Factory Tech, who works on the 4R100's at the factory has already said NOT to run synthetic fluid in these transmissions. They were not built for it.

Frankly, I would believe the guy who builds them.

JMHO

 

Yea I agree Mercon III

 

i have changed my converter too and am using M3 as recommended by JDM. i'm pretty sure they come stock with the M5 do they not? i know the 5 is synthetic and the 3 is not.

 

They come with the mercon III stock!
They DO NOT come from the factory with the mercon IV!

Albert

 

Been running Mobile 1 synthetic since new. No problems.

99L
Black

 

NO SUCH THING AS MERCON III

You guys have really got to start and pay a little more attention to your manuals if you are going to do your own truck work or give out suggestions to other people. The atf used in our lightnings from the factory is MERCON. I have had Redline high temp atf in my truck since june and, I have heard of other guys using the Royal Purple atf all without any problems. The dealership changed the atf in my truck (didn't have anything to catch the 16l) and I believe they just drained the pan and convertor. I don't think this method would be as good as using the pump for getting all of the old oil out but, the pump would require more of whatever atf you are using in order to flush the old oil. Don't mean to sound like I'm preaching but before you give someone suggestions on what to do make sure you know what you are taking about.

 

I guess if you want to get technical, you are correct!
Straight off the bottle!!
MERCON also meets DEXRON III automatic transmission fluid

Albert

 

Does anyone have the torque specifications for both the 4R100 pan bolts and the 12-bolt differential cover? Looking to change some fluids and upgrade both covers.

 

I'm about to give B&M Trick Shift a shot when my new B&M tranny pan goes on.

 

I'm 99.9% sure these trannys come with Mercon5 which is a 30% synthetic blend. I was told this from a driveline engineer from Ford.

 

Mercon, not Mercon V

4R100 pan bolts - 16 ft/lbs

 

I didn't really say not to use synth fluid, I said I don't. As far as Mobil 1, I know an engineer who says it's the best stuff to use, hands down, so it'll work, and some people like it, I don't, but mostly because of the price, not because it won't do a good job. Now what I did say, is don't use MERCON V, the fibers will unravle in it is what I'm told, but I know it's a big no-no.

G