I'm posting on here to vent about my experience so far with the quality of service I've received from one of the local Ford dealerships in the area.

A few months ago, I noticed that I had a leak coming from the rear differential. I saw the telltale dark liquid film on bottom side of the pumpkin, and upon a closer look, it was originating from the pinion seal area. I figured that it wasn't a big deal, it should be an easy fix. I know pinion seals just leak sometimes (it's a common issue for that style of seal). I wasn't even bothered by it. This is where the trouble started.

I took the truck into the dealer for the seal change. They told me it was a 2 hour job, but I got a phone call 45 minutes after dropped the truck off saying they were done. I went and picked the truck back up, and as I was driving out of the small town when I heard it. There was a very subtle hum coming from the rear end under load from about 35mph and up. It was hard to notice, and once you got above 55mph, the wind noise was able to overpower it. I was able to turn the noise on and off by lightly applying throttle. Under accelleration it was there, it was gone as soon as I would coast.

Now let me just say that I worked for 8 years in my career as an assembly process engineer for drivetrain assemblies. It was literally my job to create factor assembly processes for transmissions, axles, and other drivetrain components for heavy equipment machines. I am intimately familiar with the process of setting up a differential correctly and the impact of preload on a bearing's life. I also was the one responsible with issue resolution and failure mode analysis, so I'm familiar with root cause analysis and figuring out what went wrong.

What I assumed happened was that the tech took a shortcut and didn't properly torque the pinion nut back and either had slop in the system, or over torqued the nut and crushed the sleeve further, increasing the preload on the pinion bearing and causing the noise. I took it back to the dealer and they agreed that there was a noise coming from the rear end and they were going to order new bearings and other required parts to replace it to set it properly.

Come time for the repair, and they have my truck for a couple of days to do the swap. I knew this was going to be a bigger job because I've swapped rear end gears in my Mustang myself and knew what they were in for. When I left the dealership, I had the fans off an radio off because I wanted to be sure the noise went away.

To my disappointment, the noise was worse then when I left. Only not it is gear noise on acceleration and coast. I called them back immediately upon getting home, and they agreed that it's not right. I am waiting on follow up from their tech to talk about next steps. It's a shame, because the truck was 100% quiet from the factory. It all started with that leaking seal, and now my rear end is F'ed up and it's turning into a whole fiasco.

More to come as it gets worked out. I'm not just going to let it slide though. My truck is brand new with only 15K miles on it, so if I leave it go now, I'm going to be the one to pay for it once it fails after warranty.

 

Open a case with Ford.
That way they know there is a problem.
Its also the first step to the lemon law ( in TX ).
I know a lot of Dealers do not want Ford to know when there are multiple repairs on the same problem.

 

As you say. It’s a pretty straight forward repair. It should be obvious now that the tech does not have much experience or just doesn’t care. Since it’s a warranty issue, I would consider taking your truck to a dealer that has a much higher service volume.

 

I don't want to do lemon law or anything like that. The truck is fine, it's just the rear end having issues not caused by the factory. If anything, I would push for them to replace the entire rear axle assembly with a new factor assembled axle from Ford. Not sure if they do that or not, but I would much rather do that then use the lemon law. The issues that would be driving me to do a lemon law are purely caused by the dealer technician at this point. It may end up being lower cost from Ford to swap out the assembled rear axle then it would be to keep diving into the rear end. Much less labor.

I will likely reach out to Ford customer service to let them know of my experience with the service techs at this particular dealership. I've had great customer service so far with the service managers I've worked with, but it's pretty clear that the techs that have worked on my truck so far haven't been great.

There are a lot of Ford dealers here in the Peoria, IL area, and I could shop around to find the one with the most experience with setting up differentials. There are a lot of people I work with that also drive F150's, so I can get recommendations and ask around.

 

I understand you don't want to do the lemon law.. no one does.
Just make Ford aware of the issue so they can try to help.

Then, later if things get worse, you have done the first step, notified the manufacturer.

 

Sorry to hear that! I wouldn’t be that happy either it’s brand new! I just re did my axel because the housing was damaged in an accident. So I know how much of a bear the crush sleeves can be! My guess is they used an impact on it.... anyways if they can’t get it right the next time I would be talking to ford and telling them you want a complete axel installed if they aren’t competent enough to fix yours. To me it seems a bit excessive to lemon law the truck over the issue it should be easy enough to remedy.

 

Is the rear limited slip? Is there a chance they did not use friction modifier when fluid was replaced? I know that most of the fluid used now has friction modifier in it. But, I always ask and get it on the ticket.

 

Never mind, it is a 2019 and limited slip was not available if I have kept up properly on options.

 

Correct, no LS option. But the OP is right, the tech working on his truck is in-experienced in rear end work. To properly replace a pinion seal, one has to disassemble the complete rear end since the pinion gear has a crush sleeve which is used to set the gear lash. They can only be used once. What the tech did was just removed the yoke, R&R the pinon seal and replaced the yoke. After re tightening the pinon nut, he crushed the sleeve further which changed the gear lash, and thus the whining sound. Trying to save time on a seal replacement in rear end gears just doesn't work.

 

Other than taking a long time, the pinion seal swap should be easy to do without requiring any re-shimming of the differential. The only tricky part would be setting the correct rolling torque, but shouldn't impact the gear setting at all. If you just go with an impact wrench, your not doing it right.

I also made sure I checked the locking function on my differential since my truck comes with that. It still works. I turned it on and then went around some corners and made sure the wheels scuffed around the turns (it was wet and slushy out, which made it easier to spin the inside wheel). That all checked out.

 

At the very least, the tech could have saved some time by marking the nut and yoke and counting turns meticulously. Still not the right process but would have probably gone back together (the first time) better than it did.

At this point, I'd be concerned that the gears have been meshing two different ways than factory and this will possibly cause wear issues down the road even after it is fixed.

 

For just replacing a seal this works extremely well (with meticulous being the key function here). I replaced just a seal on my 2004 F250 at 310K and never had an issue. I hate diff work but it's just because I don't have the measuring tools. It's not something I'd recommend just anyone do.

 

I wonder if the OP ever received a resolution?

 

Uptring the name of the dealer?

 

Not to revive a dead thread, but commenting to add closure.

Summary (dealer names left off intentionally):

• Leaking pinion seal was replaced by Dealer #1.
  • Result: bearing hum under light load from rear differential
• Dealer #1 attempted to replace bearings. They had the truck for almost a week because they said they were missing a rear differential gasket (I think they just had it low on the priority list or were working through staffing issues).
  • Results: Ring & pinion gear whine under acceleration, deceleration, constant speed and coast. Not overly loud, but constant and noticeable.
• At this point, I didn't trust that the mechanics at Dealer #1 would be able to successfully resolve the issue, so I reached out to dealer #2. Dealer #2 is a Saleen Ford dealer and had a good service reputation with many of my co-workers who have had family history and know people within the dealer service department.
• Dealer #2 was able to resolve the issue on the first try, they billed it as warranty work. My truck was there less than 24 hours. The drive home was silent, no rear end noise at all. Was a quiet as the day I drove it off the lot when I bought it.