Differential or Transmission Clunk

[The_Chemist]

I picked up my Longhorn Tuesday night. So far I have less than 150 miles on it.

Today driving home from work, I started hearing a clunk and can feel a slight jolt when starting and stopping in slow moving traffic (such as creeping your way up to a stop sign, waiting for your turn to go).

I'm disturbed by this and don't know if it will continue doing this until something self-destructs.

The clunk sound appears to be coming from the rear end. Maybe the differential or transmission....

I have a 3.92 gear ratio and a non-etorque engine.

Is this normal?

On another note, I can hear something rolling around inside the dash every time I stop or start moving. Guess the boys at the factory dropped something in there during assembly.

You think the assembly people would take pride in their work!

Any ideas on the clunk noise?

 

[Jordan2929]

September 11, 2018 - Flash: Drivetrain Control Module (DTCM) Diagnostic and System Improvements - # 08-116-18

Mind adding the build date to your signature?

 

[Billet1500 4x4]

I picked up my Longhorn Tuesday night. So far I have less than 150 miles on it.

Today driving home from work, I started hearing a clunk and can feel a slight jolt when starting and stopping in slow moving traffic (such as creeping your way up to a stop sign, waiting for your turn to go).

I'm disturbed by this and don't know if it will continue doing this until something self-destructs.

The clunk sound appears to be coming from the rear end. Maybe the differential or transmission....

I have a 3.92 gear ratio and a non-etorque engine.

Is this normal?

On another note, I can hear something rolling around inside the dash every time I stop or start moving. Guess the boys at the factory dropped something in there during assembly.

You think the assembly people would take pride in their work!

Any ideas on the clunk noise?

U-Joint possibly.

 

[The_Chemist]

September 11, 2018 - Flash: Drivetrain Control Module (DTCM) Diagnostic and System Improvements - # 08-116-18

Mind adding the build date to your signature?

Yeah, I'll check to see what the build date is and add it. I assume it can be found on the door jamb sticker?

 

[The_Chemist]

U-Joint possibly.

Oh geez!

 

[stubright]

Not sure when yours was built, but there is a trans flash that fixed mine and it shifts perfect now. I also had the flash done for the amp (HK Radio) there was also a update for the anti-lock brakes as well. All the updates would depend on your trucks build date

 

[The_Chemist]

September 11, 2018 - Flash: Drivetrain Control Module (DTCM) Diagnostic and System Improvements - # 08-116-18

Mind adding the build date to your signature?

Before I add the build date to my signature, I looked on the door jamb sticker and it states 9-18 for the build date. How do I find the exact day and time?

 

[The_Chemist]

Not sure when yours was built, but there is a trans flash that fixed mine and it shifts perfect now. I also had the flash done for the amp (HK Radio) there was also a update for the anti-lock brakes as well. All the updates would depend on your trucks build date

All I can find so far, is that the truck was built in September of 2018. I can't find the exact day on the door jamb sticker!

I really do hope it's as simple as just a flash to fix the issue!

I always hate taking my vehicle into the dealer for service! It usually comes back worse than what it was before it went in, from past experience.

 

[Jordan2929]

Well there goes that theory, this TSB is for trucks built before July 1st.

 

[The_Chemist]

Found the build date though.

It's 9/24/2018. 8:00 pm.

 

[Billy James]

Found the build date though.

It's 9/24/2018. 8:00 pm.

Where did you find that? I only saw Month/Year.

 

[The_Chemist]

Where did you find that? I only saw Month/Year.

Look over on the right hand side of the sticker, underneath the bar code. There will be big letters that say "Truck". To the right of that, there will be "MDH", then a 6 digit code. The code is month, day, hour.

 

[Billy James]

Look over on the right hand side of the sticker, underneath the bar code. There will be big letters that say "Truck". To the right of that, there will be "MDH", then a 6 digit code. The code is month, day, hour.

Thanks. I found it. It says 080206. I am assuming the 06 is 6 AM.

 

[The_Chemist]

Thanks. I found it. It says 080206. I am assuming the 06 is 6 AM.

Yes. It uses a 24 hr time. format. 6pm would be 18.

 

[SpeedyV]

It would be great if it's a software fix. Your description sounds a bit like the slip yoke has too much play.

 

[RBRK]

It’s normal, nothing wrong with your truck. It’s a 8 speed trans charachteristic. My 13 did it and my 19 does too. I mainly notice it on freeway on ramps waiting for our metering lights. Slow stop and go traffic. On and off the throttle, seems like something is wrong, but it’s not. Feels like major backlash In the drivetrain.

 

[The_Chemist]

It would be great if it's a software fix. Your description sounds a bit like the slip yoke has too much play.

I'm hoping it's just a simple reprogram issue. It kind of feels like a really hard downshift into first gear, or a differential "clunk". The joy of new vehicle ownership.

 

[The_Chemist]

It’s normal, nothing wrong with your truck. It’s a 8 speed trans charachteristic. My 13 did it and my 19 does too. I mainly notice it on freeway on ramps waiting for our metering lights. Slow stop and go traffic. On and off the throttle, seems like something is wrong, but it’s not. Feels like major backlash In the drivetrain.

Your description sounds like what I am experiencing. I noticed it also when I was pulling into a parking spot and just about getting ready to stop. I felt something like a really hard downshift and a "clunk" then a slight jolt.

I guess I'll monitor it for a while and see what happens.

 

[RBRK]

There is a transmission update that will fix the harsh downshift when almost stopped. Mine is built late May it helped mine. Hard to say what program is in your truck being a later build. The only option it going to the dealer and having them hook it up and see if there is a software flash available. The other issue is a normal characteristic, not that it’s desireable. I haven’t been in that slow crawl situation since I had my transmission software flash to confirm if it’s any different there or not but the harsh downshift while slowing is gone.

 

[rparth139]

I picked up my Longhorn Tuesday night. So far I have less than 150 miles on it.

Today driving home from work, I started hearing a clunk and can feel a slight jolt when starting and stopping in slow moving traffic (such as creeping your way up to a stop sign, waiting for your turn to go).

I'm disturbed by this and don't know if it will continue doing this until something self-destructs.

The clunk sound appears to be coming from the rear end. Maybe the differential or transmission....

I have a 3.92 gear ratio and a non-etorque engine.

Is this normal?

On another note, I can hear something rolling around inside the dash every time I stop or start moving. Guess the boys at the factory dropped something in there during assembly.

You think the assembly people would take pride in their work!

Any ideas on the clunk noise?