Driveline Shudder/Vibe

[Spurshot]

2014 1500 CC LTZ 5.3L (6L70/6L80?) 4WD. 

 

I was towing my jeep up to the Rubicon trail Sunday, when I noticed the driveline would vibrate/shudder under light acceleration while cruising on the freeway.  Never heard this before. We pulled over and checked the rear driveshaft and it all looked and felt good. No grease or debris around the U-joint trunions, etc. No looseness in the U-joints.  

 

We unhooked the jeep and drove it the rest of the trip, but we were still getting the vibration.  Definitely torque related.  Only vibrates/shudders under load.  

 

I have some ideas as to what it might be, but I trust the opinion of some of you more.  @Grumpy Bear where are you?

[KARNUT]

1 minute ago, Spurshot said:

2014 1500 CC LTZ 5.3L (6L70/6L80?) 4WD. 

 

I was towing my jeep up to the Rubicon trail Sunday, when I noticed the driveline would vibrate/shudder under light acceleration while cruising on the freeway.  Never heard this before. We pulled over and checked the rear driveshaft and it all looked and felt good. No grease or debris around the U-joint trunions, etc. No looseness in the U-joints.  

 

We unhooked the jeep and drove it the rest of the trip, but we were still getting the vibration.  Definitely torque related.  Only vibrates/shudders under load.  

 

I have some ideas as to what it might be, but I trust the opinion of some of you more.  @Grumpy Bear where are you?

I had experienced that with a different brand. Changing the fluid fixed it.

[Spurshot]

1 hour ago, KARNUT said:

I had experienced that with a different brand. Changing the fluid fixed it.

I did a full fluid and filter change a year or so ago and haven't put more than maybe 4-5k miles on it since.  The fluid (GM Dexron) looks clean, pinkish and smells fresh.  

[kickass audio]

just for the heck of it, pull the fill plug on the rear diff and look for excess metallic flakes on the plug. There is another magnet at the bottom of the diff but you can start with the easy one that won't require a draining to inspect. The transfercase i'm pretty sure had the magnet on the drain plug not the fill plug.

 

If you jack it up on all 4's, how do the wheel bearings feel? Also spin the driveshaft and see how the pinion bearing feels, maybe it's starting to fail on you.

[Spurshot]

57 minutes ago, kickass audio said:

just for the heck of it, pull the fill plug on the rear diff and look for excess metallic flakes on the plug. There is another magnet at the bottom of the diff but you can start with the easy one that won't require a draining to inspect. The transfercase i'm pretty sure had the magnet on the drain plug not the fill plug.

 

If you jack it up on all 4's, how do the wheel bearings feel? Also spin the driveshaft and see how the pinion bearing feels, maybe it's starting to fail on you.

I had the same thought, although I don't have a safe place to put all four on stands, just 2.  But it's a 2wd issue anyway.  The issue is that it's load/torque related and jacking it and running it unloaded won't get the issue to show.  I had the truck on downhills and it wouldn't show at the same speeds, due to lack of load.   I'll pull the cover on the rear diff.  No big deal.  I have lots of gear oil and the cover gasket is metal/rubber. 

[Grumpy Bear]

5 hours ago, Spurshot said:

2014 1500 CC LTZ 5.3L (6L70/6L80?) 4WD. 

 

I was towing my jeep up to the Rubicon trail Sunday, when I noticed the driveline would vibrate/shudder under light acceleration while cruising on the freeway.  Never heard this before. We pulled over and checked the rear driveshaft and it all looked and felt good. No grease or debris around the U-joint trunions, etc. No looseness in the U-joints.  

 

We unhooked the jeep and drove it the rest of the trip, but we were still getting the vibration.  Definitely torque related.  Only vibrates/shudders under load.  

 

I have some ideas as to what it might be, but I trust the opinion of some of you more.  @Grumpy Bear where are you?

 

V8 right? 6L80E? AFM delete or still using it? That's a question not a statement.  How many miles? 

 

Gut says converter. But what's my gut know.  Got a shop local that can run diagnostics. Honestly. Someone you trust. Someone with a computer and a vibration monitor. HELP @newdude. 

 

Kind of a V6 guy. Sorry.  

[Spurshot]

8 hours ago, Grumpy Bear said:

 

V8 right? 6L80E? AFM delete or still using it? That's a question not a statement.  How many miles? 

 

Gut says converter. But what's my gut know.  Got a shop local that can run diagnostics. Honestly. Someone you trust. Someone with a computer and a vibration monitor. HELP @newdude. 

 

Kind of a V6 guy. Sorry.  

Yes, V8 5.3L. AFM still theoretically active, but never comes on due to the larger tires, topper and heavy load that is almost always in it.  It wasn't AFM kicking in, as this was when throttle was rolled in.  

 

My gut says converter as well.  But have never felt a failing lock-up converter.  

 

I have no trusted shop that I've used, since I do all my maintenance.  I'm at the mercy of Yelp. 

 

What was that better torque converter brand you recommended?  

Edited August 9 by Spurshot

[newdude]

2 hours ago, Spurshot said:

Yes, V8 5.3L. AFM still theoretically active, but never comes on due to the larger tires, topper and heavy load that is almost always in it.  It wasn't AFM kicking in, as this was when throttle was rolled in.  

 

My gut says converter as well.  But have never felt a failing lock-up converter.  

 

I have no trusted shop that I've used, since I do all my maintenance.  I'm at the mercy of Yelp. 

 

What was that better torque converter brand you recommended?  

 

 

Do you have any access to a diagnostic scan tool that can read transmission data?  Sadly most small cheap handhelds can't do it otherwise I'd recommend one.  My point being if you can have your TCC slip speed monitored live to see what RPM of slip is occuring.  If its the torque converter, you should see an erratic slip speed when cruising or giving it some light acceleration at moving speeds, 35-80mph range.  If its dancing between 0-100+rpm, its time to open up the transmission.  There are more in-depth ways like with a PICO Scope but that's gonna add up diag time at a dealer/shop that has one.  

 

How is your transmission temps?  Have you installed the lower temp TBV at any point yet?  Assuming you haven't, my ballpark is temps should be 190-200F when up and running warmed up which is "technically" normal if your truck is stock (no updated TBV).  

 

If you don't have a way to watch TCC slip, I'd suggest dropping the pan and checking the magnet for excessive debris.  If you can watch TCC slip and its bad, I'd go beyond just swapping the torque converter and go for a transmission disassemble.  Converters in these 14-19 trucks quite often will not only fail, but they will in the process damage the fluid pump and beyond.  The 4-5-6 clutch is another victim too. 

Edited August 9 by newdude

[Grumpy Bear]

3 hours ago, Spurshot said:

Yes, V8 5.3L. AFM still theoretically active, but never comes on due to the larger tires, topper and heavy load that is almost always in it.  It wasn't AFM kicking in, as this was when throttle was rolled in.  

 

My gut says converter as well.  But have never felt a failing lock-up converter.  

 

I have no trusted shop that I've used, since I do all my maintenance.  I'm at the mercy of Yelp. 

 

What was that better torque converter brand you recommended?  

 

I knew @newdude would have excellent advice  

 

CADILLAC, CHEVY, GMC Torque Converter 77-JMBXSD (floridatorqueconverters.com)

 

Or Circle D will build one. 

 

You may not find your exact trucks description, but the 77-JMBXSD is the unit. CALL THEM and confirm. 

[Spurshot]

12 minutes ago, Grumpy Bear said:

 

I knew @newdude would have excellent advice  

 

CADILLAC, CHEVY, GMC Torque Converter 77-JMBXSD (floridatorqueconverters.com)

 

Or Circle D will build one. 

 

You may not find your exact trucks description, but the 77-JMBXSD is the unit. CALL THEM and confirm. 

Thanks again for that converter reference.  I've read on "the other truck forum" that GM had updated their Dexron VI ATF due to "shuddering" issues.  I changed my ATF maybe last year or 2022, but hadn't put many miles on it. From what I can tell with my partial gallon container of genuine GM Dexron VI, it's likely the old stuff. 

The base stock of old GM Dexron fluid (19355656) has the ability to attract low levels of moisture, which can cause degradation of the coefficient of friction of the fluid. The new fluid (19417577) has a new GTL (Gas to Liquid) base stock that is able to tolerate more moisture. Shuddering transmissions and torque converters have been recovered with the new fluid. New transmission fluid tests have been developed due this issue to prevent it from occurring with new transmission fluids."

 

Some owners are going to Mobil 1 LV HP or Amsoil and gotten rid of the shudder.  Had a torque converter shudder last week | Chevy Silverado and GMC Sierra Forum (silveradosierra.com)

 

I also did the pill flip on the thermostat.  

 

So, I ordered some Amsoil Signature Fuel Efficient ATF.  We'll see.  I know even if it "fixes it", it's likely to eventually reveal itself again.  I hope to move on to a new truck before it comes around again. 

 

[Grumpy Bear]

9 minutes ago, Spurshot said:

Thanks again for that converter reference.  I've read on "the other truck forum" that GM had updated their Dexron VI ATF due to "shuddering" issues.  I changed my ATF maybe last year or 2022, but hadn't put many miles on it. From what I can tell with my partial gallon container of genuine GM Dexron VI, it's likely the old stuff. 

The base stock of old GM Dexron fluid (19355656) has the ability to attract low levels of moisture, which can cause degradation of the coefficient of friction of the fluid. The new fluid (19417577) has a new GTL (Gas to Liquid) base stock that is able to tolerate more moisture. Shuddering transmissions and torque converters have been recovered with the new fluid. New transmission fluid tests have been developed due this issue to prevent it from occurring with new transmission fluids."

 

Some owners are going to Mobil 1 LV HP or Amsoil and gotten rid of the shudder.  Had a torque converter shudder last week | Chevy Silverado and GMC Sierra Forum (silveradosierra.com)

 

I also did the pill flip on the thermostat.  

 

So, I ordered some Amsoil Signature Fuel Efficient ATF.  We'll see.  I know even if it "fixes it", it's likely to eventually reveal itself again.  I hope to move on to a new truck before it comes around again. 

 

 

Curious. How many miles on this unit? 

 

I'm not a "The sky is falling" sort of guy but when these converters let go, they take nearly everything with it. They are not making new pumps anymore, so I'm told. Just say'n. Kind of playing Russian Roulette. But yes, fluid can be an issue. 

[Spurshot]

2 hours ago, newdude said:

 

 

Do you have any access to a diagnostic scan tool that can read transmission data?  Sadly most small cheap handhelds can't do it otherwise I'd recommend one.  My point being if you can have your TCC slip speed monitored live to see what RPM of slip is occuring.  If its the torque converter, you should see an erratic slip speed when cruising or giving it some light acceleration at moving speeds, 35-80mph range.  If its dancing between 0-100+rpm, its time to open up the transmission.  There are more in-depth ways like with a PICO Scope but that's gonna add up diag time at a dealer/shop that has one.  

 

How is your transmission temps?  Have you installed the lower temp TBV at any point yet?  Assuming you haven't, my ballpark is temps should be 190-200F when up and running warmed up which is "technically" normal if your truck is stock (no updated TBV).  

 

If you don't have a way to watch TCC slip, I'd suggest dropping the pan and checking the magnet for excessive debris.  If you can watch TCC slip and its bad, I'd go beyond just swapping the torque converter and go for a transmission disassemble.  Converters in these 14-19 trucks quite often will not only fail, but they will in the process damage the fluid pump and beyond.  The 4-5-6 clutch is another victim too. 

Thanks for this information.  

I'll see if my Palmer Performance app is still active.  

I suspected the transmission/converter right away and pulled up trans temp on the display.  It kept its cool, mostly running in the mid 180s on the flat at 70 ish mph in 100+ ambient temps, while towing my 5000 lb jeep.   On the rest of the trip, it would maintain reasonable temps from the 180s to around the 208 range in the Grapevine (pass) while not towing.  RPM didn't look to be fluctuating on the factory tachometer. But I was trying to avoid the shudder by running in a lower gear or staying out of the throttle when possible. 

 

When I changed fluid a year ago, I put a pan on that I had welded a drain bung on.  That should make the job less messy.  

[Spurshot]

29 minutes ago, Grumpy Bear said:

 

Curious. How many miles on this unit? 

 

I'm not a "The sky is falling" sort of guy but when these converters let go, they take nearly everything with it. They are not making new pumps anymore, so I'm told. Just say'n. Kind of playing Russian Roulette. But yes, fluid can be an issue. 

It's at 114,222 miles now.  Seems like I changed the ATF about 108k.  I'll look into that.  I have a record somewhere.  I don't know if it's coincidence that this shudder came along shortly (miles wise) after the fluid change or it's related.  But, I also started towing my jeep more in the last year than years before.  I've probably towed it 5000-6000 miles in the past 18 months, as opposed to maybe 2000 miles the entire 4 1/2 years before that. 

 

I appreciate what you're saying about the converter taking out the trans.  

[newdude]

1 hour ago, Spurshot said:

Thanks again for that converter reference.  I've read on "the other truck forum" that GM had updated their Dexron VI ATF due to "shuddering" issues.  I changed my ATF maybe last year or 2022, but hadn't put many miles on it. From what I can tell with my partial gallon container of genuine GM Dexron VI, it's likely the old stuff. 

The base stock of old GM Dexron fluid (19355656) has the ability to attract low levels of moisture, which can cause degradation of the coefficient of friction of the fluid. The new fluid (19417577) has a new GTL (Gas to Liquid) base stock that is able to tolerate more moisture. Shuddering transmissions and torque converters have been recovered with the new fluid. New transmission fluid tests have been developed due this issue to prevent it from occurring with new transmission fluids."

 

Some owners are going to Mobil 1 LV HP or Amsoil and gotten rid of the shudder.  Had a torque converter shudder last week | Chevy Silverado and GMC Sierra Forum (silveradosierra.com)

 

I also did the pill flip on the thermostat.  

 

So, I ordered some Amsoil Signature Fuel Efficient ATF.  We'll see.  I know even if it "fixes it", it's likely to eventually reveal itself again.  I hope to move on to a new truck before it comes around again. 

 

 

 

The HP fluid was "updated" multiple times, Dexron VI has not changed though.  The highlighted bit you have there and the part #s listed are the HP which used to be Dexron LV HP ATF and now is Mobil 1 LV ATF HP, p/n 19417577.  HP is for 8 speeds.  

[kickass audio]

15 hours ago, Spurshot said:

I had the same thought, although I don't have a safe place to put all four on stands, just 2.  But it's a 2wd issue anyway.  The issue is that it's load/torque related and jacking it and running it unloaded won't get the issue to show.  I had the truck on downhills and it wouldn't show at the same speeds, due to lack of load.   I'll pull the cover on the rear diff.  No big deal.  I have lots of gear oil and the cover gasket is metal/rubber. 

You could try to jack just the rear up and torque load the engine by giving it throttle and brake at the same time. I'm thinking it's the pinion bearing for sure but you can also pull the brakes off and check the seals for leaking that might be causing the bearing to fail but a wheel bearing failure would be constant at all times, loaded or not. 

 

Also, since it's pretty easy, try pulling the driveshaft off and get a little drip pan to catch the fluid that will dribble out of the transfer case yoke and see how the ujoints feel in your hand. My dad had ujoint failure on his old tahoe where it would ride fine and randomly would vibrate like you had the brakes on. Then it started to squeak when backing up (sounded like a rubber duck haha) and we pulled the driveshaft then found the ujoint on the rear by the axle was dried out. Surprisingly it didn't tear the seals on the joints but those needle bearings were so dry and rusty it was only a matter of time before it exploded. We also noticed on the ujoints near the yoke that they were very tight to try and move around. Changed both ujoints and he was good as new again.