I am helping my brotherinlaw attemt to diagnose a transmission issue.
As state above it is a 2000 f450 4x4 about 250 k miles. Has had at least 4 transmissions replaced that we know of. It has a very large transmission cooler with a fan on it mounted under neath the truck. The transmission before this one went out after the truck was used to pull a heavy load on a fifth wheel trailer over a 4x4 road in low range. Brother in law did not notice that he was overheating tranmission ( because of the load but also a fuse went out that had the tranny cooler fan on it. The transmission was 30 days out of a 2 year warranty. So it was not covered. The tranny case was cracked he found out when he pulled it apart . So he got a used case to start with. Appearently some of the clutch packs were welded together because of the overheating
He decided to do the rebuild himself because of $ issues.
So he put in a new heavy duty rebuild kit to include a new TC.
Blew out the coolers and lines ect . 100$ for new fluid plus a new filter.
Goes to town with new tranny and gets 10 bales of hay and goes back to the ranch to feed out the hay. Stops and feed hay goes to move the truck and truck does not move unless it revs very high. He did have reverse for a short time in the field but that was soon gone. Current condition is it will not move at all. Condition of fluid is slightly discolored but he thinks that is because of the assembly lube he used to put it back together
he did nothing to the selinoid pack other than drain it and put it back it.
I do have access to a new snapon code reader which we have not used.
He walked away from the truck about 45 days ago because he was so mad and frustrated.
he has decided to take another look at it to see if he can figure out what went wrong. He has yet to pull the pan off to see what might be in the pan.
Any ideas , thoughts or suggestions ? He is thinking that he will start with the code reader and by checking for line preasure.
Thanks in advance

John

 

Pulling the pan is a waste of time. Revving it high to try to get it to move guarantees that the trans is fried.

If I had fixed that trans I would not honor the warranty. He cooked it by overworking it with a non-functional cooler. That is not the fault of the trans builder.

 

OK
so i did not mean to imply that the transmission should have been warrentied. I was trying to give some baseline information about the previous issues so that you or someone else could possibly give a more informed opimion about what might be wrong with the current transmission.. I realize that you would be guessing at best but that is what I am seeking is a more informed opinion than what i am able to make.
So back to the issue at hand what might be wrong withe the tranny now ?
or what steps short of another teardown could we take to diagnose the issue.
I have read threads for the better part of 2 days but have been unable to find a good overall trouble shooting thread.
I am not a mechanic but i do read well and learn fast and it does not make sense to me that it would work well for say 30 miles after a rebuild and the just quit with no warning.
unless it was not getting any fluid back to the back of the transmission after the rebuild because of something he missed during the rebuild ie that big cooler is pluged or the bypass valve is stuck open
So a little more info than it is broke dont bother to take the pan off might be helpful

PLEASE
Thanks John

 

Where are the parts from? In particular the TC. Did he replace the pump when he did the rebuild? Are you sure the parts were heavy duty? Was the solenoid a stock part or heavy duty from another rebuild? Does the fluid smell? I have already done a wipe out of my TC driving in a field. It only took a few minutes. And I had paid about $1,100.00 for it. I would hook up the code reader and see what it says.

 

i do not know where the pats are from. I do not think he did anything with the pump. he was trying to save money and I know that it not the way to save money but now I am trying to get him moving again on diagnosing and fixing this truck.
Probably like trying to "shine turds" at this point but I am looking for help with diagnosis
Thanks for responding to the post
any more questions or ideas ?

John

 

I don't know that much about the trans. Every time I had one rebuilt I had a new pump put in. And they seemed to think it was important to do something to the solenoid. Springs or something. Not sure. The original trans doesn't shift into gear, it slips so it is smoother. If you don't change that to a firm shift then you will have problems again. I thought there was a trans forum here?? They might have more info. Or call some of the sponsors that rebuild them and ask. I think BTS is good. Or you might be able to find out what they do and replace on the internet. Like I say I don't know that much about it, but this will give you a bump back up anyway.