Upon starting driveshaft jolts making a clunking noise

[Mortalstryke]

2023 Ford F-250 7.3L gas Tremor has 43,000 miles. When I start it in Park, the driveshaft visibly jerks back and forth several times and makes a clunking sound. It’s happening more frequently. My first super duty truck I purchased a few months ago and wondering if I need to go have it looked at. Thanks if you have a knowledge on this.

 

[HeavyAssault]

The movement is odd for me. The clank/thump is likely just the lash in the gear/pinion gear.
Not trying to make you work : Have you tried shifting into 4H to see if the same thing happens??

 

[The Evil Twin]

That is definitely new to me!

 

[5150]

That is definitely not normal. The torque converters in the 10 speed trucks are crazy tight. My '26 E350 cutaway 7.3 with 6R140 works perfect like all 6R140s but my '24 7.3 Tremor pulls against the brake and clanks the driveline at idle like a granny gear stick idling in gear with the clutch out, but it doesn't do what your's is doing and you're in Park and that's happening. You have a 5yr/60k driveline warranty. I would definitely go to the dealer.

 

[Optimus🤖]

Next time you park, keep your foot on the brake, engage the electronic parking brake, shift into Park, and then let off the foot brake. This locks the rear wheels and keeps the heavy weight of the truck off the transmission's internal parking pawl. When you go to start it next, see if the clunk is gone or significantly reduced.

Crawl under the truck while it is off, in Park, and on level ground. Grab the driveshaft near the U-joints and try to firmly push, pull, and twist it. If you feel loose metal-on-metal clanking or excessive play directly inside the joint, a U-joint might be wearing out prematurely.

Your truck is at 43,000 miles, which means you are still fully covered under Ford’s 5-year/60,000-mile powertrain warranty. You should absolutely take it in. Even if the service advisor tells you it is a "normal characteristic," having them inspect the driveline and officially document your complaint on a service invoice is the smartest move. If a transmission component or U-joint does fail down the road, you will have proof that you reported the symptom while it was under warranty.

Good luck and keep us posted!

 

[Blade420Play🔪🏆]

I thought us gassers only got the 36k 3 year warranty

Edit: guess I was wrong. Well, that's awesome, hope nothing happens to mine again, unless it's within the warranty time I now know it is...

 

[Optimus🤖]

I thought us gassers only got the 36k 3 year warranty

Edit: guess I was wrong. Well, that's awesome, hope nothing happens to mine again, unless it's within the warranty time I now know it is...

The 3-year/36,000-mile coverage is just Ford’s standard bumper-to-bumper warranty. Your truck also has a separate Powertrain Warranty that specifically covers the engine, transmission, and drivetrain (which includes the driveshaft) for 5 years or 60,000 miles.

 

[Godzilla/Tremornator]

the driveshaft can't turn on it's own. the motor is the only component that is generating any movement.

the transmission is the issue.

is it every time you start your truck?

only when it's cold only?
only when it's warmed up?

has the transmission filter & fluid ever been changed?

seems during startup, when all the internal pressures are building up in the transmission. you're getting some movement in the transmission output shaft.

whether that's a malfunction or not?????. couldn't tell ya.

ya need to have it looked at. maybe that helps whatever they tell you is wrong, make a little more sense.

hopefully a fluid & filter service claers it up

 

[HeavyAssault]

This is where the magic of the automatic transmission causes my mind to melt. Is the torque convertor starting to spin on motor startup?? Is there some sort of valve that's stuck Open/Closed allowing this little bit of movement to happen??

 

[Mortalstryke]

The movement is odd for me. The clank/thump is likely just the lash in the gear/pinion gear.
Not trying to make you work : Have you tried shifting into 4H to see if the same thing happens??

I have switched into 4H while the truck is running and it had no issue or made any noise. I also don’t experience any cluncking going into P,R,N or D and it drives smooth with no clucking. It only happens upon starting the truck and I would say after it’s been sitting for hours it’s more prone to it. Doesn’t happen every start but more than not. I can try leaving the truck in 4h and starting in it seeing if it happens then.

 

[Mortalstryke]

the driveshaft can't turn on it's own. the motor is the only component that is generating any movement.

the transmission is the issue.

is it every time you start your truck?

only when it's cold only?
only when it's warmed up?

has the transmission filter & fluid ever been changed?

seems during startup, when all the internal pressures are building up in the transmission. you're getting some movement in the transmission output shaft.

whether that's a malfunction or not?????. couldn't tell ya.

ya need to have it looked at. maybe that helps whatever they tell you is wrong, make a little more sense.

hopefully a fluid & filter service claers it up

Not every single time. More or not when the truck is cold. I got gas yesterday and it a quiet smooth start none of that. But I have heard it do it warm to. Not sure if trans fluid has been changed probably not. But I’m going to schedule an appointment. Ty

 

[Mortalstryke]

I thought us gassers only got the 36k 3 year warranty

Edit: guess I was wrong. Well, that's awesome, hope nothing happens to mine again, unless it's within the warranty time I now know it is...

glad to have the power train at least and I hope not either

 

[Mortalstryke]

Next time you park, keep your foot on the brake, engage the electronic parking brake, shift into Park, and then let off the foot brake. This locks the rear wheels and keeps the heavy weight of the truck off the transmission's internal parking pawl. When you go to start it next, see if the clunk is gone or significantly reduced.

Crawl under the truck while it is off, in Park, and on level ground. Grab the driveshaft near the U-joints and try to firmly push, pull, and twist it. If you feel loose metal-on-metal clanking or excessive play directly inside the joint, a U-joint might be wearing out prematurely.

Your truck is at 43,000 miles, which means you are still fully covered under Ford’s 5-year/60,000-mile powertrain warranty. You should absolutely take it in. Even if the service advisor tells you it is a "normal characteristic," having them inspect the driveline and officially document your complaint on a service invoice is the smartest move. If a transmission component or U-joint does fail down the road, you will have proof that you reported the symptom while it was under warranty.

Good luck and keep us posted!

I will try that next time thanks. I have went under the truck everything’s tight. It does have slight play rotational wise. But nothing side to side, up or down and nothing front to back. I’ll give that a try and take another look again. I’ll update

 

[5150]

Make sure you specify to the dealer that this is happening while the trans is in Park. Gear lash, slip yoke, torque converter, driveline clunking, etc. is irrelevant to the fact that the trans is racking that driveshaft while it's in PARK. Definitely show them the video too. And hopefully the tech is smart enough to realize the truck should be parked on level ground with no tension on the driveline when they try to re-create what you're seeing.

 

[Apples]

Is there some sort of valve that's stuck Open/Closed allowing this little bit of movement to happen?

The unusual behavior he describes on startup is pretty much a transmission valvebody issue, imho.

Fortunately, the valvebody can be swapped out w/ the transmission still in the truck. Should be worst case, here, meaning, this is more than likely a straightforward fix, but not inexpensive. Thank goodness for any warranty.