5R110 w issues on a 08 6.4 4x4
 

Started flaring between 3rd and 4th I changed the pressure solenoid and the direct clutch and no change. Flushed the tranny and changed filters and no change the oil is not burnt. When it flares it goes into a safe mode on the dash and will shift perfect through 4th gear no issues. I guess I've always know if it's bad it's bad but I don't understand why it works in a safe mode but slips in regular. Also if it is a bad tranny will a 3c2p-7000 work as a swap in my truck. Thanks for the help

Mileage on trans?
What did the fluid and filter look like when you changed it?
Has this trans had regular fluid and filter service at or before the recommend intervals?
3c2p-7000 Googles out to be for an 2003, E250. A 2003 is likely a gas 4R100. The 08 is a diesel 5R110W. Two completely different transmissions. 9 of 10 times you are better off having your case rebuilt if a rebuild is needed. There is a difference between the gas and diesel and maybe between model lines as well? Certainly between years.
Proper trans troubleshooting procedure with this trans or any modern automatic with a trans control module or TCM is to read pending and present codes from the TCM as well as fluid pressure tests. Knowing this info will zero in on the problem(root cause).

Conditions
 

Filter was good oil was good, tranny has 105k on it I took it to a shop and they said it's bad need a rebuild.I can get codes from it tonight. If a tranny is bad it's typically bad not working in safe mode and not in regular driving so this one is new to me. I have reprogrammed it back to stock just incase and no change. The 3C2P-7000 lists as a 5R110W 4x4 fitting an 08, donor truck for it is an 04 F450 4x4 trying to do this on a quick budget while I spend the money to bullet proof mine.

Mark K can give you the answer to exactly what limp mode is. He did explain it here a while ago. Put that into the Googler as that works far better than the search here. Unless Mark catches this before you have that chance. I plugged that part number in and it spit out the info in my previous post. IMO rebuild yours with all the service pack updates then change fluid every 25-35K there on. Flush the cooling circuit before installing the new assembly. Another option is to find a good reman that dynos the trans before shipping. It will/should come with a warranty too.

There is no specific limp mode. That's a myth.

If the PCM detects a problem that prevents a gear from being available, it won't try to shift to that gear. For example, if the direct clutch is hurt and the PCM detects it the trans won't shift above third gear, because doing so would rely on the direct clutch. If the intermediate clutch has a problem it will shift 1-2-4-5, skipping third, where it would need the intermediate.

Thanks for the help so I'm guessing a new Transfer then. Love this forum it came up tops in every search I did on the transmission. I appreciate the quick responses to my questions. I have it tuned with a H&S any recommendations on style of torgue converter I do not pull with it, mainly daily driver sitting on 37.