2009 f350 cc lb. v10. manual hubs and manual 4x4. when I put it into 4x4 high everything seems fine. but when I let off the gas and it decelerates it makes like a weird hum. I has just checkin it out and getting ready for winter. was on a long straight road so I put it in 4hi for a minute to check things out. kinda did it last year too but seems worse this year

 

How many miles and have you ever changed to transfer case lube?

 

170k miles. I bought it this year. Should i change fluid and see what happens or take it to 4x4 repair shop and let them check it out?

 

change the fluid first.

 

Ok. Thanks. Just the stock motorcraft stuff should be fine?

 

Yes, read the manual as to the type of the fluid.

 

fluid was dirty. bought the motorcraft transfer case fluid, and put it in. still makes the noise. when I let off the gas, it almost sounds like when you slow down a car by putting it in a lower gear. my mechanics buddy is going to open up front dif, change fluid and do an inspection

 

keep at it. You will find if something needs rebuilt.


Normally you service the front diff around 100K miles as well. Unless it has been contaminated

 

Ok. mechanics buddy checked it out. Said its common to be a little loud on dry pavement. Opened front dif. Said looks like work was previously done. Everything looked good. Just swapped fluid. Hope hes right

 

If it all checks out and you have done your maintance (which you now have) then run it.


I had a Jeep that would wine a lot. It was just the way it was.

 

Some vehicles whine from day one until you sell it.

 

Yes,your mechanics buddy is correct. These 4WD units are not meant to be driven on hard dry surfaces. They will make more noise than normal and if turned tightly will bind up the transfer case. They need some tire slippage to operate properly.

 

ya,. I will not turn the tires in 4x4 on dry pavement. just drive it in a straight line to get everything lubed and moving every once in a while

 

My last 4 trucks were manual hubs. All bought new. They all wined a little at speeds higher than 30 or so. I have buddies that have said they have gone 70 mph in 4 wheel (all esof)and I could never imagine going that fast in 4 wheel drive. My new truck has esof, it will be interesting to see how it sounds at speed. I believe yours is normal. If we ever get any fricken snow, Almost 10,000 miles and no snow to speak of. Must be because of the new plow.

 

50-60 mph in 4 hi is about all I will do. It would go more but then if you needed faster then the roads must be good enough for 2hi.