Okay let me start off saying thank you for this site. The transmission in the 04 f150 fx4 is giving me fits. It was brought to me already out of the truck the buddy said it was losing reverse making a clunking noise then just stop moving completely. I went through it found the servo snap ring broke got all the broken part of snap ring out of the valve body did the full rebuild. Then he brought the truck and I found the flywheel broken around the bolt pattern so I figured that's why it wouldn't move. Okay so it worked great for 5 miles or so then when I stop and take off it neuatral then bam goes to first. Man. first dose fine did have code 720 replaced the oss . still same problem. Went back through the valve body no sticking valve and no codes now. Any help would be app. thanks steven

 

am I not seeing my replies or just not getting any or everybody is as stumped as I am im fixing to pull it back out and see if I cut the lip seal when putting it together .

 

It's asking a bit much to expect someone knowledgeable to give you a reply within 90 minutes - it IS a work day and this forum isn't THAT active. Be patient.

It's also a bit difficult to read and understand your post when it's just one long runon sentence with hardly any caps or punctuation.

 

Sorry about that I did not do well in English glass that's why I am a mechanic. I will try not to runon [run on] sentence with hardly any caps or punctuation. I am just getting frustrated with this tranny . I am sure I will figure it out thanks.

 

By "still the same problem" do you mean that after replacing the OSS you still have a P0720 code? That would indicate that the wiring to the OSS was damaged.

 

No I do not have any codes now. The problem is still being in drive at a stop take off move maybe two feet then acts like goes in N rpms rev. then slam into first.

 

That is probably a pressure issue. You might want to put a pressure gauge in the test port and see if line pressure drops out when this happens. You need a 0-350 PSI gauge with a 1/8" NPT thread.

 

You absolutely positively sure that transmission fluid is full up? Start with the stupid stuff and work your way from there.

I have had professional mechanics stand in front of me and bet their entire existence that the fluid is full. When I wipe the stick, reinsert it and show them a dry spot below where they say the level is and ask them how you can get a dry spot on a dipstick that is supposed to be fully immersed in fluid... That's just fun.

Not saying this is the problem by any means, Just saying I would triple check and make sure before you move ahead.

 

Okay after tear down only thing I find is the reverse drum clutches need to be between .40-.59. I have .83 so I gees I need a thicker snap up to a .106 is what book shows. My ? now is dose the reverse and low work off same set of clutches? Didn't cut no lip seals that was good thing

 

Reverse and first are not on the same clutch and that extra 23 thousandths clearance really isn't going to cause huge issues on the reverse clutch. I would get the right snap ring for sure, but that isn't your problem.

 

When I first rebuilt this trans. I had to replace the sun shell be cause it was rubbing the center support, but now I see the new is rubbing as well ,but not like the first one . When it sets down in there its putting pressure on the one way planetary and I believe that's the problem will see .

 

When you first rebuilt the transmission did you replace the bearings?

D

 

No sir which bearings you referring to.

 

My concern is over that shell rubbing, A lot of times the incorrect bearing or bearing kit is purchased and the bearing that goes in between the sun gear and sun shell is too short. This will cause both rubbing in that spot you are referring to and a short total stack height in the transmission.

D

 

If your referring to the needle bearings they looked just fine . When I set the sun shell down in the center support its fine no rubbing , but just a little pressure pushing down and the sun shell rubs center support and one way don't seem to work properly .