My father-in-law has a 1972 Econoline E250. Lately it has been making a humming sound from at least transmission to the rear differential. I want to help him out but not knowing Ford's all that well, especially van's I wanted to know if anyone has dealt with this in the past. He has had the differential replaced in the last 2 years. He has also changed the drive shafts u-joints in the rear drive shaft. He is wanting to change the u-joints that connect to the transmission as well as possibly the yoke. Since he is a shade tree mechanic, some of his friends have recommended putting grease in the rear diff as well as changing out his transmission fluid. He has said that there is no transmission oil pan and that in order to change the filter in the transmission, he would have to disconnect it from the engine and fill it from the dip stick tube. I have not done much research on this either but I am not sure where to start.

If I replaced the transmission, do I have to find another E250 van? Is there a truck that is compatible that I can pull the transmission from? Are the differentials compatible from trucks to vans? If so what years? Any clue what his humming sound could be? Thank you all for reading and helping.

 

You have to be more specific when you hear this. Is the van moving? Auto trans?No pan. Never heard that on a 72 unless it is a manual shift. Did you check oil levels in trans and diff.? What exactly was done with the differential? Was the whole assembly changed out? From what you describe, my bet is the differential.Some make noise and will go on living forever. Hard to tell if it is gear or bearing noise from your description.

 

The van is moving when it hums, although I have not been with him, I am just going off of what he tells me. It is a manual shift and yes we have checked every oil level, to include the diff. The entire differential was replaced before, as in the entire assembly. He is insistent on it being the gears within the diff but the one time I did go under the van, I noticed the holes in the the exhaust pipes. It could be the excessive noises from that, I also feel it could be the drive shaft, whether it is a bad u-joint or perhaps just the fact that it is old. I want to keep him from spending money, but with out having the right amount of experience, it is hard to keep him from just guessing.

 

There is a big difference between gear noise and exhaust noise. U joints generally will cause a bad vibration, especially starting from a standstill and a squeek which changes pitch from a standstill and quiets down around 25-35 mph.Raise the back wheels off the ground and you can check the u joints for any slop and also check the pinion for any sideway slop. Also, look for any powdered rust on the u joints. Replace them if you notice play or rust.Gear noise usually will either occur during accelerating or decelerating. If it happens all the time when in motion, look for bearings. Pinion or wheel bearings.

 

I have inspected the U-joints, there is no play in them. The vibration does happen when the van is accelerating and slowing down but I have inspected the drive shaft at both ends and seems fine. I am going to try and record the noise for this forum and another to see what it sounds like to others.