Failing bearing in front drive unit, just diagnosed at 112,647 miles.

[21st Century Truck]

No

What im saying is you might be able to buy a granger warranty and get it fixed under warranty...

Ahhh... I really didn't think of that. Thanks for the idea - I'll dig into this a bit.

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[chl]

I wonder if your travels to extreme climates along with the miles and "hard" driving you mentioned had an effect on the bearing lube/coolant fluid? They often say change fluids more often when under harsh conditions.

You mentioned "drain & refill of the rear electric motor's Mercon fluid, as the indicated drain & fill interval is at 140 thousand miles" and you are nearing that.

If the fluid has degraded then it could be causing the noise you are hearing.

"Degraded fluid can no longer provide the proper protective cushion between moving gears, potentially resulting in whining sounds or mechanical wear... A rough, grinding, or loud continuous whining could indicate worn-out bearings in the motor or degraded fluid that is no longer protecting the reduction gears. "

If they are not too far gone, just flushing and changing the fluid might do the trick.

 

[21st Century Truck]

I wonder if your travels to extreme climates along with the miles and "hard" driving you mentioned had an effect on the bearing lube/coolant fluid? They often say change fluids more often when under harsh conditions.

You mentioned "drain & refill of the rear electric motor's Mercon fluid, as the indicated drain & fill interval is at 140 thousand miles" and you are nearing that.

If the fluid has degraded then it could be causing the noise you are hearing.

"Degraded fluid can no longer provide the proper protective cushion between moving gears, potentially resulting in whining sounds or mechanical wear... A rough, grinding, or loud continuous whining could indicate worn-out bearings in the motor or degraded fluid that is no longer protecting the reduction gears. "

If they are not too far gone, just flushing and changing the fluid might do the trick.

Yes we (the brother engineer and I) agree with Your post here, and the other one above about the old AAMCO car.

We independently came to the same conclusion - to request a drain and flush in order to change the Mercon fluid, and also to wash out whatever might have gotten in there especially assuming the bearings are bushing-type bearings, as a flush of new fluid with its cleaning additives might potentially arrest or at least slow down the diagnosed condition and remove the impurities. I figure I might as well have this done to both front and rear motors as this can't hurt and it might well help.

I appreciate everyone's ideas here... the power of the forum hive mind is impressive.

Besides, this action is a far cheaper step than pulling off the front motor in labor costs and in component cost, so it's worth a try.

 

[CrisB02]

All of this sounds a bit scammy. I did a quick search for electric motors and found a few on eBay. Just by looking at the pictures you can see that the bearings would be behind the external oil seal some of those are designed to be serviced in place. Doing the flush in my opinion isn't going to yield much. If you are out of warranty, why not contact a indy shop that does work on electric cars have them pull the motor and replace bearings. If it doesn't work order up a eBay drive and drop it in and you are on your way down the road. I have not faith in Ford techs....... Common sense still applies to EV's.

 

[Ffxdude]

Folks,

For general information, a good EV tech I had known for years just diagnosed a failing bearing in the front drive unit.

Symptoms: this past Sunday while driving on cruise control at a speed of about 65 mph on a limited access highway I heard a new constant low-volume sound that reflected off the concrete center highway divider. The sound was a low-level thrumming, and only present when the motors were not under load. When I applied the gas pedal, the low level thrumming disappeared. When I (or the cruise control) let off the gas, the low level thrumming reappeared and stayed constant. The thrumming was definitely on the front left side of the truck.

On further testing, the low level thrumming would manifest at and above speeds of about 12 mph. It would grow with increased speed until it plateaued into a constant noticeable although not overwhelming background level, at about above 25 mph. There was some slight, constant gas pedal vibration as well, although far less noticeable.

Today, after some thorough shop testing and road testing, the diagnosis is: a bearing inside the front drive unit which is beginning to fail. The truck is evaluated as "driveable, but..."

Of course (sigh...) my truck is 12,647 miles beyond the Ford extended EV warranty.

The practical choices are two:

- drain the traction battery [edit:] coolant, remove the offending front drive unit (i.e. the front electric motor), disassemble the electric motor, remove and replace the failing bearing, reassemble everything.
- or drain the traction battery [edit:] coolant, remove the offending front motor, replace the entire front motor, reassemble everything.

We are awaiting the status of available front motors before I and the shop make action decisions. Apart from checking the supply of same, the shop estimates that, based on labor costs and the necessary replacement of other electric motor components like single-use stretch bolts etc., the overall price of a bearing replacement vice a full motor replacement would likely be close to a wash.

Assuming I will authorize one or the other (I'm leaning on a full motor replacement right now) I will also request a drain & refill of the rear electric motor's Mercon fluid, as the indicated drain & fill interval is at 140 thousand miles or about 26 thousand miles away now, and since the overall labor to drain & fill the electric motors closely resembles the labor to pull and fix the front motor anyway i.e. drain the traction battery, remove the battery armor plates, etc. etc. This way, both motors would have their drain & fill maintenance mileage reset together.

FYI - the price seems to be around $11 thousand - salty but better than the price of a new car. We've driven the truck far, wide and sometimes, pretty hard hehe.

I am posting this info here for general awareness... maybe it'll be helpful to others.

Did it sound like this? Noise starts at about 3 sec mark.

 

[21st Century Truck]

Did it sound like this? Noise starts at about 3 sec mark.

I appreciate the question. The answer is"No".

My noise is akin to a low level grinding or rolling around of walnut shells or other small irregular objects. It is also even and not pulsing when it appears in REGEN mode (i.e. when coasting or slowing down).

Your noise sounds to my ear like a slightly bent shaft of some sort, rubbing at its bend.

Hope this is a helpful answer.

 

[21st Century Truck]

UPDATE: my truck this past Saturday went into the Yellow Wrench IPC mode. Basically it said the following, quoted here verbatim, via the Ford App:

"Powertrain Malfunction / Reduced Power

What is Happening?

Illuminates when the system has detected a powertrain or a four wheel drive fault.

What Should I Do?

A Powertrain or All Wheel Drive / Four Wheel Drive fault has been detected, contact your authorized dealer as soon as possible, schedule service."

I drove home for the 20 or so miles. However, once home and shut off for 30 minutes, this fault never reappeared again.

On self-investigation I now have the following present, inactive DTC in the SOBDMB:

"P0B0D - electric / aux trans fluid pump "A" Motor Control Module".

In response I'm planning to do a transmission flush of the rear motor, and to replace the front motor.

 

[21st Century Truck]

UPDATE: this is what the transmission fluid pan looks like on the now-removed front motor with the failing bearing(s) and failing internal Mercon pump.

 

[Heliian]

failing bearing(s)

That is failed. Probably clogged the pump or the sense circuit.

Glad you got it changed.

 

[21st Century Truck]

That is failed. Probably clogged the pump or the sense circuit.

Glad you got it changed.

...yeah, just in time. Or, alternately, about 12,670 miles TOO LATE

 

[Firn]

Wonder if its worth it to have the dealer do a fluid change and check for metals right before the 100k warranty expires

 

[21st Century Truck]

Wonder if its worth it to have the dealer do a fluid change and check for metals right before the 100k warranty expires

That's my recommendation now. As well as a cooling radiator fluid change and also a brake fluid change. Might as well do them all, at one sitting.

 

[electricpig]

UPDATE: this is what the transmission fluid pan looks like on the now-removed front motor with the failing bearing(s) and failing internal Mercon pump.

Yikes!

 

[TaxmanHog]

UPDATE: this is what the transmission fluid pan looks like on the now-removed front motor with the failing bearing(s) and failing internal Mercon pump.

NASTY!

 

[21st Century Truck]

NASTY!

Yes it is.

The wonder of it all is that the front drive unit and the whole truck had kept on working, rolling along, from the 1st diagnosis at 12,670+ miles to the motor replacement at just about 16,000 miles.

I'm not sure whether a gasoline motor with bearings eroded to that degree would not have had a heart attack out on the road... likely just after midnight, two counties out and in a driving rain of course.

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