Tire Skip Noises after PTU/RDU Fluid Change

[motaur]

Hi all, owner of a '25 Hybrid Lariat (AWD). I decided to change the PTU, RDU, and oil this weekend after reading so many stories of the PTU being underfilled. As many others have reported, the PTU/RDU fluid were very dirty, had lots of metallic sheen in them, and plugs had a lot of gunk on them.

Since changing these, I've started to hear my rear tires sort of skip when backing into my garage or turning at very low speeds. The sound is like a low dull creak or someone spiking an over inflated ball (hence my assumption it’s the tire). It seems like just a noise of one rear tire spinning at a different rate than the other.

I have only had the truck for about 2000 miles, so I’m unsure if this is a new noise or if all of the AWD models do it. In the attached video you can hear it at the very beginning and then again around 30ish seconds.

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[MavStangVa]

I would say take it to the dealer. However if they say the PTU or RDU has the wrong fluid or amount of fluid they will likely not cover it. Why would you change the fluid at 2k miles? I know many alarmist posts on here.

 

[motaur]

If there was any chance they were under filled or had debris they could be doing significant damage to a vehicle I’d like to keep a long time. And these services should be pretty straight forward. The PTU was in fact under filled, so that feels justified.

As for wrong type or quantity of fluid, that seems next to impossible. I bought and used the Motorcraft fluids from my local dealership, and you can’t overfill them since any excess would leak out of the fill plug hole.

 

[MavStangVa]

If there was any chance they were under filled or had debris they could be doing significant damage to a vehicle I’d like to keep a long time. And these services should be pretty straight forward. The PTU was in fact under filled, so that feels justified.

As for wrong type or quantity of fluid, that seems next to impossible. I bought and used the Motorcraft fluids from my local dealership, and you can’t overfill them since any excess would leak out of the fill plug hole.

This is not a sarcastic question. Do you think Ford would underfill the units hoping they would fail just after the warranty ends so you would buy another Maverick? Seems bad business. Take it to the dealer. If you bought the fluid from them then they can't argue it's wrong. Maybe you had a problem developing and it got more noticeable after the drain and fill.

 

[motaur]

I don't know if this is your norm, but please stop treating me like an idiot. No, I don't think they're maliciously under filling units. But I also know that people and manufacturers are not perfect and it is absolutely possible for these problems to exist. If I don't get any helpful responses here, obviously I will take it to the dealer. In the meantime, I'm looking to hear from people who might have some insight or experience on this specific issue.

 

[Carlitos_92]

Hi all, owner of a '25 Hybrid Lariat (AWD). I decided to change the PTU, RDU, and oil this weekend after reading so many stories of the PTU being underfilled. As many others have reported, the PTU/RDU fluid were very dirty, had lots of metallic sheen in them, and plugs had a lot of gunk on them.

Since changing these, I've started to hear my rear tires sort of skip when backing into my garage or turning at very low speeds. The sound is like a low dull creak or someone spiking an over inflated ball (hence my assumption it’s the tire). It seems like just a noise of one rear tire spinning at a different rate than the other.

I have only had the truck for about 2000 miles, so I’m unsure if this is a new noise or if all of the AWD models do it. In the attached video you can hear it at the very beginning and then again around 30ish seconds.

In the video, is your foot touching the brake at all? The only "normal" thing I can think of is that the brakes will creak if you are riding them at low speeds like that. Maybe triple-check that you got the correct fluids in the respective locations?

If that noise happens and you know you did the procedure correctly, and your foot is nowhere near the brake pedal, I'd get that checked out ASAP. I don't know how a properly done fluid change would cause anything like that. It sounds like something is binding, whether inside the PTU/RDU or in a CV joint.

 

[motaur]

Yes, foot is on the brake. This is basically only happening when at ultra-low speed when doing things like pulling into/out of parking spots, the garage, or driveway. But it's definitely coming from the rear, so brake noise seems unlikely. It definitely sounds more like when the tires hit a bump.

Feels unlikely that I swapped the two fluids, but I'm not going to say it's impossible. No idea how to double check that at this point aside from redoing it with the correct stuff. Thanks for the ideas.

 

[MavStangVa]

I don't know if this is your norm, but please stop treating me like an idiot. No, I don't think they're maliciously under filling units. But I also know that people and manufacturers are not perfect and it is absolutely possible for these problems to exist. If I don't get any helpful responses here, obviously I will take it to the dealer. In the meantime, I'm looking to hear from people who might have some insight or experience on this specific issue.

Sorry, I did not mean to treat you like an idiot. At the time you had posted exactly 2 comments on the forum. So I was asking legitimate questions. There are many who post that Ford recommended maintenance is designed to get to 60,001 miles so you have to buy another Ford or pay through the nose to repair. Just verifying you had some FAITH in Ford to build a reliable vehicle. you should not have issues at 2k miles so schedule a visit to the dealer.
Here is another legitimate question so please do not get offended. You said foot is on the brake when you hear this. It is possible your anti-collision is causing the brakes to pulse? Possible a bad controller. Again a dealer issue to fix.

 

[710-oil-614]

I don't know if this is your norm, but please stop treating me like an idiot. No, I don't think they're maliciously under filling units. But I also know that people and manufacturers are not perfect and it is absolutely possible for these problems to exist. If I don't get any helpful responses here, obviously I will take it to the dealer. In the meantime, I'm looking to hear from people who might have some insight or experience on this specific issue.

Yes, pacify your concerns of (an obvious) problem instead of taking it to a dealer first.....

Unfortunately - the drain plugs are marked so they will know the fluid has been changed, also know that you purchased the fluids from them, and if you can't show that it was performed by an ASE certified mechanic they will likely not cover it under warranty.

Definitely sounds like you've got a bad RDU. I've changed both out without issue and I'm about to do them again.

 

[Carlitos_92]

Yes, foot is on the brake. This is basically only happening when at ultra-low speed when doing things like pulling into/out of parking spots, the garage, or driveway. But it's definitely coming from the rear, so brake noise seems unlikely. It definitely sounds more like when the tires hit a bump.

Feels unlikely that I swapped the two fluids, but I'm not going to say it's impossible. No idea how to double check that at this point aside from redoing it with the correct stuff. Thanks for the ideas.

I would try it without touching the brake if you're able. Maybe on a tight turn rather than in the garage. Then at least you could rule that benign possibility out.

The only other non-bad thing I can think of is the truck suspension settling after being jacked up, but it seems like you have moved the vehicle enough since the fluid change that it would've settled by now. Also an easy thing to rule out with a few good shoves on the ends of the truck to give the shocks/springs a flex.

Unfortunately both of those are unlikely.

 

[Meeka]

Sorry, I did not mean to treat you like an idiot. At the time you had posted exactly 2 comments on the forum. So I was asking legitimate questions. There are many who post that Ford recommended maintenance is designed to get to 60,001 miles so you have to buy another Ford or pay through the nose to repair. Just verifying you had some FAITH in Ford to build a reliable vehicle. you should not have issues at 2k miles so schedule a visit to the dealer.
Here is another legitimate question so please do not get offended. You said foot is on the brake when you hear this. It is possible your anti-collision is causing the brakes to pulse? Possible a bad controller. Again a dealer issue to fix.

I don't know if this is your norm, but please stop treating me like an idiot. No, I don't think they're maliciously under filling units. But I also know that people and manufacturers are not perfect and it is absolutely possible for these problems to exist. If I don't get any helpful responses here, obviously I will take it to the dealer. In the meantime, I'm looking to hear from people who might have some insight or experience on this specific issue.

Jeez MavStangVa, you try to help some people and they just start ragging on you! That should not happen here on MTC, but…..Unappreciative?

 

[Mudduck]

Jeez MavStangVa, you try to help some people and they just start ragging on you! That should not happen here on MTC, but…..Unappreciative?

Reminds me of my Gradpa's favorite saying growing up.... "I got hit at and missed, then shit at and hit"

 

[Techcar]

The one thing I would try and see if it works or not is turn off the traction control. The 2019 Ford ranger I have will make the same noise if I have it cut on when I'm moving slowly so now I turn it off before I ever move the truck which also seems to have cut down rear brake pad wear. Just a thought.

 

[BLUEOVALRACER]

Hi all, owner of a '25 Hybrid Lariat (AWD). I decided to change the PTU, RDU, and oil this weekend after reading so many stories of the PTU being underfilled. As many others have reported, the PTU/RDU fluid were very dirty, had lots of metallic sheen in them, and plugs had a lot of gunk on them.

Since changing these, I've started to hear my rear tires sort of skip when backing into my garage or turning at very low speeds. The sound is like a low dull creak or someone spiking an over inflated ball (hence my assumption it’s the tire). It seems like just a noise of one rear tire spinning at a different rate than the other.

I have only had the truck for about 2000 miles, so I’m unsure if this is a new noise or if all of the AWD models do it. In the attached video you can hear it at the very beginning and then again around 30ish seconds.

Does the RDU require a friction modifier additive?

 

[Msradke]

There is a Ford tsb for that problem

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