97 E4OD strange sound diagnosis

[fixitforfree]

Just bought a 97 F250 PSD, 2wd, 3.55 gear with an E4OD auto. Tranny shifts as new, fluid is very clean with no odors. All seems perfect with the exception of a faint grinding or roaring noise that is heard at cruising speed. I hear this noise any time the driveline is "loaded" - in other words starting up any kind of grade not matter how small the grade is there is this grinding noise that almost sounds like a rough bearing sort of. The noise isn't loud but is very distinct that's it not the engine I'm hearing. But, when going down a small grade and the driveline "unloads" it goes away. I can shift into neutral while it's making the noise and the noise goes away... I'm just positive it's coming from the area of the tranny. Doesn't sound like a rear end and clearly seems like it's not a u-joint but I can't pinpoint the issue.

FYI, my truck had a Jasper tranny installed by the previous owner almost 4 years ago but only 15,000 miles ago (replaced at 137k, now has 152k). Previous owner bought the truck new and never had any trouble at all until the tranny went out. Like I said, it shifts and performs fine now but this noise tells me something is wrong.

Could anybody help me diagnose it or give me tips if you've had similar sounds from your E4OD?

[fixitforfree]

Noone have any insight to my E4OD "sound"? I have a hard time believing if it were something real serious that my tranny would shift and perform as good as it does but...

What are the odds that I have a torque convertor bolt loose that's causing the convertor to resonate at certain speeds and give the odd sounds I'm hearing? I'll take my "dust cover" off this weekend and maybe this will be evident but I just want all the insight I can get at this point.

Thanks.

[pablito]

Try Shifting to neutral at highway speed to see if it changes any, I would think that would eliminate the torque converter?

[Chop]

It may be the carrier bearing or a dry u joints,simple fixes and not to costly.I wouldn't think converter bolts are loose.It could be time to "rebuild " drive shaft.

[fixitforfree]

I took it to a local tranny rebuilder that is very well respected and been doing it for years. He drove it with me, said he hears the noise, agrees it is "rpm related" but says without a doubt it is not the transmission. He says it shifts and acts perfectly and he would take off anywhere in it. That's good news but I know there is something wrong and still can't find the noise. And, as you inquired, I can shift it into neutral and the noise goes away instantly... I have a hard time believing this is the case and it has nothing to do with the tranny...Shifting into neutral doesn't keep the driveline or rear diff from turning so what else could it be but the tranny? Also, the tranny guy turned overdrive off and we still hear the noise so he says that eliminates the planetary gearset since, in O/D off mode, he says the planetaries aren't doing anything.

[pablito]

What if you are going up a hill in town at say 35 mph, does it make the sound under load at the lower mph like on the highway?

[Chop]

I don't want to suggest possible torque convertor shudder,being expensive and time consuming,but i just did .There is a guy on here Fordnutzs,I think he knows about transmissions than all of us put together ,maybe he will chime in

[STROKED_NY_023]

Long or short bed? Two piece drive shaft?? Carrier bearing???

[Spud Monkey]

Sounds like what my 95 PSD is doing except mine occurred after changing the filter and fluid and emptying the torque converter, I think its torque converter on mine. maybe this will help

[fixitforfree]

Originally Posted by pablito

What if you are going up a hill in town at say 35 mph, does it make the sound under load at the lower mph like on the highway?

I'm not going to say it isn't there at slower speeds like 35mph but it's not noticeable like it is at 55mph and over. I've had several people ride with me aside from the tranny guy and the all hear exactly what I hear but noone is confident at what it might be. One even suggested it could be the rear diff "transferring" it's sound up more toward the front of the truck. It just doesn't sound like it's anywhere near the rear diff. Sounds more toward the front like the tranny or maybe or forward most u-joints or carrier bearing.