When pulling 8000 lbs to 10,000 lbs up hills now the trans goes from OD to 3rd or 4th and there was a time when it never dropped out of OD and never dropped more than 1-2 mph. when empty it runs like new. no noticeable slip of the trans. Could it be my air filter? there is a 2.5 mpg drop in the overall mpg. Any one have/had this problem?

 

Have you checked the Air Filter? A real dirty Filter can cause loss of power...

 

How about the fuel filter? Have you changed it lately?

 

Thanks for the replys. It's time to change oil and oil filter, going to change fuel and air filter also.
Now my left front tire leaks down to about 50 psi every 2 days or so. got to checking the tire and the side wall close to the rim has splits in it. Found 3 tires to be that way,they are B F Goodrich OEM tires with 82,000 miles on them and have what looks like about 7 to 10,000 miles of tread left on them.
Not bad for 7 year old tires. Getting the same new tires tomorrow. 265/70/17 BFG Rugged Trail T/A for $995.00 out the door. Then i got to buy 2 battires. Thinking about sears top line battiers. Maybe after this it be at the 100,000 mile mark before any thing else needs replacing lol

 

Hi new to this but what I know is any kind of blue smoke is indicating a burnt valve or something going on down in the engine like oil leaking have you had anything internally checked