4r70w / 4r75 Torrington bearing issue

[boominXplorer]

First off the vehicle in question is my wife's 03 expedition which has the common 4r70 transmission. It shifts perfectly, acts perfect and never concerned me until here recently when I noticed a "rear end" type whine. It only happens in o/d or 3rd from 40-50 mph on 30% throttle or less. If I let off the gas its quiet. Completely silent after 50 and I don't notice it in any gears but o/d and 3rd. Its loud enough at times to notice it with the hvac blower on high but not like holy crap loud. I have seen the tsb talking about the number 9 torrington bearing and I think it could be my issue but not sure. It seems to come up when the trottle is low which doesn't go with the tsb's description. The truck just hit 140k miles. We have put an easy 1000 miles on it since I noticed the noise (could of been there alot longer as I rarely drive it) and it has remained the same. It's a 2wd 4.6 truck also that only sees 3 car seats and some groceries, never will or has towed anything.

I know the trans needs to be torn apart to fix the bearings and I might as well rebuild it while it's out. Has anyone had this issue in a 4r70 and if so how long did you wait to rebuild? Money isn't really the issue but finding the time to tear it apart before winter won't happen(I'll rebuild it myself). I'll probably drop the pan soon to check for any debris and add a drain plug in just to make sure we are not driving around a ticking time bomb.

 

[shucker1]

I think there is also a TSB out there for the same symptoms but involves the 9.75 rear end.

My 04 Expedition with the 5.4L had the same problems but the noise came in at around 45 MPH and was gone by 60 MPH.

If I'm not mistaken there is a Ford complete kit out there to fix the problem, basically rebuilding the rear end.

I wanted to drop my rear end and rebuild it but "The Bosslady" decided it was time for the 2013 Fusion Titanium.

That's her logic. If it starts to give trouble buy a new car...

 

[boominXplorer]

I really don't think it's the rear end but i could be wrong. It sounds like it's coming from right under the console/dash but noises do travel. I had an 04 f150 fx4 SuperCrew a few years back that had the same exact noise and I rebuilt the rear with no change in noise (fixed l/s at same time). It had almost 200k on it though.

I'm going to put it on my lift soon and try to isolate it. We are on vacation out of state with it now and now that I've been driving it a ton I've really noticed it. Funny thing is the wife never noticed until I mentioned it.

 

[shucker1]

Usually how that happens...

My adventure cost me a new car...

 

[boominXplorer]

We actually just got the expedition this year. It was a one owner in immaculate condition for its age. It's a fully loaded Eddie Bauer with rear captain chairs and heat/ac front seats and a really out of date nav system(all sweet for a 03 MY). I was actually looking for an 08+ Expedition EL but I REALLY didn't want a 5.4 3v. When I found the 4.6 2wd Eddie I was sold (not to mention it was way easier on the pockets).

 

[transman304]

The case to rear hub bearing is prone to failure. They updated the bearing in the 4R70E/4R75E. The bearing shell is wider but height is the same so it will interchange. They will fail to a point you could burn the direct clutch pack from output shaft moving far enough to block feed oil to pack.

 

[boominXplorer]

So after my 360mi return trip I payed more attention to it. It's most audible 43-47mph with light throttle. I only hear it between 40-50mph on the throttle with less than 1/3 pedal, any more pedal and it lightens up the noise with throttle. Now I do notice it coasting between 50-60 but very faint. If I run it to 60 mph from a stop I never hear it. The noise is definitely under my feet and it sounds like a hypoid gear whine but it's definitely not in the rear end.

Looks like I'll be gathering parts for the rebuild. Other than the revised bearing kit, any other things I should upgrade with the minor overhaul?

I'm considering trying to find an 08+ 4r75 and swapping it in but haven't figured out if there is any snag in doing the swap.

 

[boominXplorer]

So from what I found the 4r75e won't work without changing the gear set and speed sensor so a 04 4r75w would be my only bolt in upgrade and it will still have the correct sensors I need. Then I'm back at the same bearing issue possibly without rebuilding. I'm going to keep an eye out at the pick n pull (across the street from my shop) to grab one to rebuild so I can have it swapped out and back running the same day. Then if things don't go as planned I'll still have the old one I can toss back in if time is an issue. Since its 2wd it shouldn't take me more than 4-5 hours to swap out (working on a lift).

Edit: I've found there's a new part number (6l3z-7f207-a) for the forward drum that's prone to cracking in them also. The more I look at it I'm better off just tearing into my current trans and throwing in a few updated parts. I could probably even get away with doing a soft rebuild kit.

 

[Whisperingwayne]

While your in there might as well upgrade the valve body. The sonnax aode sure cure kit has all the components to cure or prevent common issues with the aode transmissions. I would also recommend the j mod, it shifts faster, prevents slippage, reduces heat, and improves overall durability of the transmission. I will say the shifts can be a bit hard while on the throttle, maybe not ideal for your wife's grocery getter. Mine chirps my 33s from 1st to 2nd in my 5.0 explorer.

 

[CDW6212R]

Here's a PDF I found recently that describes and shows the differences of the guts of the 4R70 and 75's, from the mid 90's parts through 2010 or so. I found several useful details in it. Most of the guts from any models can swap to any other models, it's just certain changes require certain groups of parts, and some items cannot be swapped, like the later ring gear due to the speed signal holes/slots.

There are 2-3 bearings in the rear which were updated to wider surfaces, and will swap to any AODE/4R trans, even some to the AOD. One bearing is thicker in the sun shell area, requiring the mating parts that provide more space for that .020-.030 thickness, the shell and it's gear for sure.

BTW, there are two upgraded Sonnax forward drums, one's about $150 on eBay, the other $185 from Summit(one extra extra clutch). Both are stronger and will work in everything but the latest 4R75 I think. I have one of each of those for two of my builds.

Also check out the driveshafts of the truck, do the u-joints if they are old or unknown. Regards,