I recently changed the transmission filter and all the Mercon V fluid (drain pan and torque converter) in my 2001 SuperCrew 4.6L w/4R70W transmission. Ever since then, when I decelerate in the speed range between 35 and 55 MPH with Overdrive on, I fairly often I heard a loud low pitched whining noise. That noise is continuous until either I hit the accelerator pedal or if the truck slows down below about 35, then it stops and doesn't reoccur for a while.

I don't hear this noise while accelerating (I suppose it could be covered up by the engine revving).
If I turn off Overdrive, I cannot get it to make the noise at all while decelerating through the same speed range.

How can I test my transmission to see what is wrong with it? I am not getting any trouble lights and acceleration seems good, though Fuel Economy is not what it used to be.

Appreciate any ideas for diagnostics to try.

Thanks

 

how many miles on od.? sound like to me your fly wheel may be rubbin something did you take it to a dealer when your tranny fluid was changed? i take mine to the dealer.. but i make it clear if they dont get it right and it causes something else to go out they bought it..

 

I have almost 98,000 miles on the truck and transmission. I changed the fluid and filter myself.

 

did you drain the torque converter when you changed it..? if not you only done half the job

 

i'm thinking i have the same problem, does your truck make a slight "rub" noise? seems like it hits a dry spot when downshifting...i was towing a 4 wheeler the other day and when i slowed down it felt like i got a slight shove in the back, let me know if you figure something out or hear anything, i'll do the same.

 

2001 4r70w

There is not a drain plug on the torque converter..... Dont waste your time looking for it....

 

yes there is pop that round rubber seal and its up there... ford takes care of mine i watch em do it when i take all my vehicles in for service atleast there is on my 99 f-150 there is...

 

There should be. Ford stopped installing drain plugs early in the 2002 model year, all 2001 trucks should have one.

 

Brandonhadnot,
Yes, I did drain the torque converter through the drain plug under the rubber seal. I used the full 12 qts for the refill.

WisconsinFX4,
Hmm, your problem sounds similar. At other times, when decelerating w/o the use of the brakes, slowing down didn't feel linear at a certain point. Almost like some thing held up or caught.

 

exactly, what would be causing this, just when i think my truck is running great (and it should be, i spent well over 2,000 dollars this past 6 months), now i have this hesitation/rub problem...what gives? ANYONE, PLEASE HELP!

 

today i came from ford dealer... i had my tranny fluid and filter and rear axle gear oil changed .. today and talked to the service tech.. who was working on my truck and the service manager bout problem. and they both tell me that is that your drive line at your front u joints and rear u joints maybe going bad.. or your gears maybe rubbing metal to metal... but if you didnt put enough tranny fluid in it will cause a bad whinning or whislting noise ... this info came from ford

 

Transmission level is fine. I'll double check the rear differential again, but it's level has been at the level of the access bolt hole. My truck is 2 wheel drive.

 

well i dont know what else to tell ya i tried ... since i was takin mine in for a servicing.. thought i'd ask someone... good luck with your truck

 

Wow dude did you neglect your trans and now after servicing it went to crap? was the fluid black? you now maybe you where a little late on servicing your trans and now something in there is messed up???

 

Nope, I had the fluid inspected color/qty when I was at the dealership about 6 months before. They pronounced it good. When I changed it, it was red-purple in color, not black. The last change was about about 30, 000 miles ago. I don't tow or carry heavy items with it; it's used primarly for my daily commute.

Do you have any suggestions I might try? Thanks.