2003 e350 s.d. 115000 miles. Problem put it in reverse not moving feather gas goes back. Goes back with light throttle but feels like something is partially locked up binding. Put in neutral and van creeps forward feather gas no difference in speed. Drop pan inspect magnet 1/8 inch on magnet pan was clean.. (At 85k I dropped the pan and there was ZERO on the magnet.) Btw I tow 12k empty trailer and 14- 15k full to my record 18 + k. I also added a second cooler about the same size of the stock unit at 40k. Looking for solution to problem 6 plus hours on the net. Possible fix sonnex brand low reverse valve modulator I installed it. Filled to proper level no difference. While searching I came across a few posts about lubegard additive. Bought 2 bottles 1 red label the only one left on the shelf 1 platinum. Drove the truck for about an hour and a half also went low 1 -2 drive neutral reverse many times. Improvement then finally success back to normal. The local trans shop quoted 1500 for a rebuild what a relief. The following morning went to ford for a full merc v flush get the other half of the old fluid out. After flush put van in reverse worse than it has ever been. Neutral now vibrates bad chugs. I buy 2 more bottles of lubegard 1 red 1 platinum 1 stressful driving forward only hours later van is back to normal. The lubegard site says it frees sticking valves and it really does imho. The purpose of this post is is a follow up to all of the threads with the same symptoms that were never followed up by a reply or a fix.

I am now adding a few comments to this because I feel it might help others.
After searching the net many times there is a (symptom described) and many replies are simply stated as you need a complete rebuild.
Or It is (internal) the common response you need a rebuild. There are no follow up posts about this.
Your seals forward clutch convertor etc. etc. Your whatever it is is burnt up.
I put my pan in the trunk of my car brought it to a trans shop that has been in business for over 30 years and described the symptoms.
Response it looks ok but you have a forward problem your seals all the way in the back of the transmission are now flat and they are worn out.

OK got it you quoted me a price.
I do not give up easy I think I can find a solution. Go back up to the top of this post.

#1 everything that I have understood about transmissions is about temp of fluid keeping it cool or lower than the limit.
# 2 extra cooler. I do not have a trans temp gauge.


The average person like me does not want crawl under their truck and drop the pan and look for anything.

So now you might be perplexed. I think ford did did an excellent job creating the 4r100 from my experience.

 

Update now at 125 k. Checked fluid and it was brown. Dropped pan cleaned magnet lots of metal on magnet. Opened and inspected magnefine filter metal not looking good. Full diy trans flush and added more lubeguard red.
300 miles later took apart another magnefine metal on magnet.
Time for a rebuild. I found a shop by word of mouth in Chicago. The person that you talk to actually does the rebuild himself.
Problem snap ring let loose.

 

Who in Chicago did You talk too for a re build if you don't mind me asking. I'm shopping around for a good rebuild

 

Glad you now understand that NO snake oil will fix a transmission.

 

Word wide this is their old address https://plus.google.com/117331014074...ut?gl=us&hl=en .
Being on a tight budget I did not shop around for the best kit clutches steels etc or a shift kit or a convertor.
He used whatever parts he put in. Looking at the receipt it looks like the labor was 1k. The bill says $ 40.00 shift kit. I really do not feel any difference and we talked about the guys that want that hard shift etc. It passed my test e350 5.4 plus dump trailer loaded total weight of 20,000 pounds my new scaled record. The key factor is the person you talk to is the person that builds your trans. He said 3 days and kept his word a rare thing imho when dealing with shops. I drive by a muscle car restoration shop all the time I stopped in and they gave me his #.