Could this cause my F550 to not go in gear after backing up

 

No, it cannot.

 

The transmission runs fine unless I back up after the truck is warmed up..then it is like its in neutral. ..were do I start

 

Is it in neutral in any gear position, or just reverse? If you also could tell me the year and engine I might have some specific help, not just generalities.

 

The only gear I have is reverse when the transmission is warm and I back into my driveway...it is a 2000 F550 7.3 Diesel. ...after truck cools off everything works again

 

It is rebuild time. Sorry.

 

...thanks....

 

I just had the same experience, but now all is good with a factory Ford rebuilt transmission and upgrade to a 6.0 cooler. Mine wouldn't go except into reverse for several days. I let it set and got a trailer lined up to haul it to the shop and backed it to where I was going to load it. It decided to trick me one more time and went into drive and low gear fine and I was able to drive it 20 miles to the dealer's repair shop.

 

The transmission is working fine...it only does not engage every once in a while..if its hot from pulling my excavator and I back in my long driveway it sometimes won't go in gear...but I let it cool and the next day it goes in gear again... I drove it today and it ran great....its as if a valve is sticking only when its hot and I back up a good distance. ...

 

That is what mine would do. I tried tightening the linkage bracket under the dash and even did a full trans flush. It seemed OK and I seven spent a week in the mountains of CO. towing a trailer with an off road rig. I was 100 miles from home and backed up to park the trailer at a friend's house. Unhitched and no drive and minimal low gear.

Sorry, but is on its way out. I didn't want to be stranded again.

 

Well its been on its way out for three years then ...I don't back up unless im in my driveway and the work day is over...if it acts up at least I'm home and the next day it works again...

 

You could do the flow test to see how long it takes to put a gallon of fluid in a bucket at idle. If your pump is going or the filter is restricted, low flow through the coolers could cause tranny overheating when towing. Does the F-550 have a transmission temp gauge?

Do you still have both coolers functional? It seems like the problem only appears when you have been towing a distance.

 

No the 550 doesn't have a transmission temp gauge. ..now that you say that I wish it did..but it is only when towing a piece of equipment that it acts up after a pretty long haul...but only if I put it in reverse and idle into a spot...but both coolers are working as far as I know...it seem exactly as you said ..like there is a restriction ...I think im gonna change the filter first....and then I would like to see if the pump is weak.

 

No the 550 doesn't have a transmission temp gauge. ..now that you say that I wish it did..but it is only when towing a piece of equipment that it acts up after a pretty long haul...but only if I put it in reverse and idle into a spot...but both coolers are working as far as I know...it seem exactly as you said ..like there is a restriction ...I think im gonna change the filter first....and then I would like to see if the pump is weak.

How long should it take to pump out a gallon of fluid at idle....?

 

You want one quart in 15 seconds flowing through the cooler lines at idle.