4r70w Whining Sound?

[SSDDBRONCO]

So the past few times I've drove my bronco I have this whining sound coming from the tunnel area, I am almost confident it's coming from the transmission(4r70w).

I can only hear it first gear, maybe second and once I past about 20 MPH it goes away. I can also hear it a little louder when I reverse. I was even reversing downhill with my foot off the gas and it still made the whining sound.

Any idea what this can be?

 

[77silver ranger]

Planetary noise , third gear is 1 to 1 so noise goes away , planetary working hardest in 1st for gear reduction thus the noise , would pull pan inspect for excess metal . Probably not a good sign , though if clean in pan may be gear noise and hopefully last awhile . 4r70s are wide ratio and have been known to have Torrington bearing failure leading to planetary failure .

 

[SSDDBRONCO]

Planetary noise , third gear is 1 to 1 so noise goes away , planetary working hardest in 1st for gear reduction thus the noise , would pull pan inspect for excess metal . Probably not a good sign , though if clean in pan may be gear noise and hopefully last awhile . 4r70s are wide ratio and have been known to have Torrington bearing failure leading to planetary failure .

Not what I want to hear. I hope it's something else. I plan to put it on jack stands and run it in gear meanwhile someone listens for where the sound is coming from. I was thinking rear end but the noise seems to close. Any chance it may be the transfer case?

 

[77silver ranger]

Hold in manual low with shifter to help isolate , if noise goes away when you shift manually helps to isolate . Typically planetary noise gets a little quieter in 2nd ( less gear reduction ) and goes away in 3rd 1 to 1 . Did it used to not make the noise with this trans ? Some have more gear noise than others and if no metal in pan may be ok . If it started making noise but used to be quiet not as good a sign . Rock crusher muncies got their name for gear noise so some is acceptable but not if new noise and metal in pan .Good luck .

 

[SSDDBRONCO]

Hold in manual low with shifter to help isolate , if noise goes away when you shift manually helps to isolate . Typically planetary noise gets a little quieter in 2nd ( less gear reduction ) and goes away in 3rd 1 to 1 . Did it used to not make the noise with this trans ? Some have more gear noise than others and if no metal in pan may be ok . If it started making noise but used to be quiet not as good a sign . Rock crusher muncies got their name for gear noise so some is acceptable but not if new noise and metal in pan .Good luck .

Ok I'll do that first and then drop the pan after, if it is coming from the trans. From what I recall after I did the swap about 2 months ago it only made that noise when reversing. After taking it for a longer drive last week about an hour roundtrip in stop and go street traffic I began to hear that noice is 1st and possibly 2nd but very faint, and it appeared to be louder when reversing.

 

[DirtDonk]

One other thing I would do before anything else (just because it's easy) is to crawl underneath and try to spin the front driveshaft by hand. This is just to be certain to transfer case is not in four wheel high.
It does not sound like the typical transfer case whine, but it can't hurt to just rule it out 100%.

 

[Broncobowsher]

The mechanical diode makes a ratcheting noise as it slips (as it should). Sounds like a fine tooth ratchet.

 

[77silver ranger]

Noise in reverse is common , and not a concern .

 

[77silver ranger]

Drain into a clean pan then check in light (sun light is best) for sparkle from metal . Then you can strain through paint strainer and reuse , should have molded rubber reusable pan gasket .

 

[SSDDBRONCO]

One other thing I would do before anything else (just because it's easy) is to crawl underneath and try to spin the front driveshaft by hand. This is just to be certain to transfer case is not in four wheel high.
It does not sound like the typical transfer case whine, but it can't hurt to just rule it out 100%.

I actually thought I was in 4 high but driveshaft spins freely. Thanks for that.

Drain into a clean pan then check in light (sun light is best) for sparkle from metal . Then you can strain through paint strainer and reuse , should have molded rubber reusable pan gasket .

Ok I'll give that shot. Great idea on the paint strainer! And ya i have the reusable pan gasket on mine. I even have a drain plug but I'll remove it all to inspect it thoroughly. Thanks

 

[SSDDBRONCO]

The mechanical diode makes a ratcheting noise as it slips (as it should). Sounds like a fine tooth ratchet.

Mine sounds more like a whine, I want to say very similar to a power steering whine?

 

[SSDDBRONCO]

Question:

Since I'll be dropping the pan should I go ahead and replace the filter?

 

[DirtDonk]

I don't remember if you said, but how old is the transmission? How old is the fluid? How long were you driving it when it did not make this sound?
Since fluid pumps can make a whine and pulling a pan is such a hassle and messy I would definitely change the filter. Maybe the existing filter is causing some sort of cavitation or restriction and flow to the pump.
I call it cheap insurance…

 

[SSDDBRONCO]

I don't remember if you said, but how old is the transmission? How old is the fluid? How long were you driving it when it did not make this sound?
Since fluid pumps can make a whine and pulling a pan is such a hassle and messy I would definitely change the filter. Maybe the existing filter is causing some sort of cavitation or restriction and flow to the pump.
I call it cheap insurance…

Transmission is for a 1998 AWD Explorer. Supposedly transmission was new from Ford and never been used when I bought it back in 2015, and it actually looked like it was never used after inspecting it before installing it. Even the fluid was bright red when I drained the old fluid out for new fluid. But what I didnt do (dumb me) is change out the original filter, so who knows that might be the culprit . I got it swapped in about 2 months ago so the swap is pretty new probably about 100 miles or so, so far.

 

[77silver ranger]

If it looks clean in pan you can even cut filter open , actually not a bad diagnostic step . Sometimes thinks can look good in pan and find a surprise in filter . When replacing filter would go with filtran brand or oe . Some of those over the counter filters are pretty cheesy . Any transmission shop or supply house wit or transtar should be able to get a filtran. Little more expensive but worth it IMO .

 

[SSDDBRONCO]

If it looks clean in pan you can even cut filter open , actually not a bad diagnostic step . Sometimes thinks can look good in pan and find a surprise in filter . When replacing filter would go with filtran brand or oe . Some of those over the counter filters are pretty cheesy . Any transmission shop or supply house wit or transtar should be able to get a filtran. Little more expensive but worth it IMO .

Good idea I'll do that as well. By OE would that be motorcraft brand? If not I'll try to locate a filtran filter. Thanks.

 

[77silver ranger]

Filtran brand is usually original equipment supplier , less expensive than buying from dealer . Best way to cut open filter is with side cutter or wire cutter as some call them . Peel back the metal crimp till you can separate metal from plastic then the element will be folded at one end , just open it up and hold up to light to see if restricted or if any unwanted debris inside .

 

[77silver ranger]

See if Transtar or WIT has a warehouse near you , if too much trouble finding just use one of the cheaper ones and put good filter in next round . If not much debris just drive unless noise gets louder then would go through same procedure. Hopefully just some gear noise , some are more noisy than others .

 

[SSDDBRONCO]

Filtran brand is usually original equipment supplier , less expensive than buying from dealer . Best way to cut open filter is with side cutter or wire cutter as some call them . Peel back the metal crimp till you can separate metal from plastic then the element will be folded at one end , just open it up and hold up to light to see if restricted or if any unwanted debris inside .

See if Transtar or WIT has a warehouse near you , if too much trouble finding just use one of the cheaper ones and put good filter in next round . If not much debris just drive unless noise gets louder then would go through same procedure. Hopefully just some gear noise , some are more noisy than others .

Ok I'll report back with an update once I do that. There's actually a Transtar not too far from me so I'll give them a try. Thanks for all the help.

 

[77silver ranger]

4r70w pan has sump like original c-4 pan , make sure to get the 4r70w deep sump filter not the aode 2wd filter and that no one has installed incorrect filter in past . Can take pan with you if going to Transtar and they will make sure you get correct filter or just take a picture of pan for them .