Light Clunks, Low Speeds, Automatic Trans?

[swamp2]

I'm just noticing a new minor clunk/thump that seems tranny (Auto, 10R60, in Raptor) related. I've got about 9k mi on my rig. I note it happening intermittently (maybe 1/3rd of the time) during braking right before getting to 0 speed. I think it is more likely under harder braking. It also happens after stopping (to 0) and after releasing the brake and then right when aoplying some gas pedal. Although it's purely an analogy, it seems like something is getting some bind and then freeing up and releasing some energy. Also seems like perhaps it's related to the vehicleso pitch motion from accel/decel.

Anyone else have this? Did it appear after not doing it? Anyone know what it is or have any educated guesses? Thanks in advance.

I've already changed my trans fluid twice, put on a higher capacity aluminum pan and changed the trans filter once (being super conservative with her...).

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[vdob]

I have the same exact issue when starting after being stopped at a light. Haven’t taken it in yet but it definitely worries me.

 

[Monster1926]

I have that in my 2 door. It’s annoying, almost seems like something is loose in the rear suspension or a U joint is toast. Best way I can describe mine is it feels like a light push from the rear while stopping and letting off the brake.

 

[Ducati1098]

May be the rear driveshaft.
I had the exact same issue of a clunk after releasing the brake pedal from a stop. Would sometimes do it coming to a hard stop also. New shaft completely fixed it.
I replaced mine at ~20k and it’s back again now at 35k. So it’ll be getting another one.

 

[swamp2]

May be the rear driveshaft.
I had the exact same issue of a clunk after releasing the brake pedal from a stop. Would sometimes do it coming to a hard stop also. New shaft completely fixed it.
I replaced mine at ~20k and it’s back again now at 35k. So it’ll be getting another one.

Thanks. What was the diagnosis exactly? I predict my/many service departments will have difficulty recognizing and acknowledging this issue... Any tips?

 

[FleshTuxedo]

Following

 

[Ducati1098]

Thanks. What was the diagnosis exactly? I predict my/many service departments will have difficulty recognizing and acknowledging this issue... Any tips?

It was more of an educated guess based on experience.
F150 dealt with a very similar concern for years and there was a TSB at one point for their 2 piece drive shaft where we would need to split the shaft and put some special grease on the splines.
I'm sure that may possibly work on the bronco also, but I just decided to replace the shaft instead.

If your concern is the same as mine was, and it is the driveshaft.. it'll eventually get worse to the point where it happens at basically every stop/go.

 

[Spooled]

my Raptor has been doing this for like 15k+ miles. It's annoying for sure.

 

[BroncoA512021]

It is actually a common issue, I think it is called the slip joint..it needs to be relubricated.

 

[swamp2]

It is actually a common issue, I think it is called the slip joint..it needs to be relubricated.

Sounds like relubing is a bandaid, no?

 

[BroncoA512021]

Sounds like relubing is a bandaid, no?

The drive shafts were replaced in the early 2021 deliveries, including mine.

 

[swamp2]

The drive shafts were replaced in the early 2021 deliveries, including mine.

??

Do you mean there was a recall? A production line recall? Is this information specifically a reply to my comment you quoted about re-lubing being a "band aid" or is it just additional info. You said it just needs to be relubed but now go on to mention replacements. I'm confused. TIA.

 

[BroncoA512021]

??

Do you mean there was a recall? A production line recall? Is this information specifically a reply to my comment you quoted about re-lubing being a "band aid" or is it just additional info. You said it just needs to be relubed but now go on to mention replacements. I'm confused. TIA.

It was not a recall, it was a "customer satisfaction" something.... Google the issue, it happens with other vehicles. It is more annoying than anything... In fact, the issue has not come up on these boards in a while. Ask your dealer service manager to check out your "slip yoke"

 

[Ducati1098]

It was not a recall, it was a "customer satisfaction" something.... Google the issue, it happens with other vehicles. It is more annoying than anything... In fact, the issue has not come up on these boards in a while. Ask your dealer service manager to check out your "slip yoke"

I think you're referring to 22B27, which was a program for the front driveshaft, but only for 21MY.
That was for one of the CV boots not being robust enough which could then lead to a rotational noise/vibration from dirt getting in the joint.
That wont apply for @swamp2 braptor.

 

[flip]

Don't have pics from way back but at one point they were coating the splines with some kind of coating to help with the sticking but didn't take care of the problem so it was, and still is to some degree, to pull the shaft, pull apart and smear a bunch of PTFE (XG-8-A) on them and call it good.

The clamp isn't serviced by Ford but I'm sure it's easily obtained on Amazon once you figure out what size it is. I've never figured out if it's the spline size/number of splines, tolerances, or something else that's caused Ford issues for multiple decades and across several models.

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