: Recall # N242454440 MOMENTARY REAR WHEEL LOCK-UP

BradN

New member
Jul 29, 2024
4
2
3
Los Alamos, NM
Anyone else experiencing this?
I bought my 2020 2500HD a few weeks ago. First trip pulling a light (3500lb) camper. Cruise set to 65 going up an incline.
BANG!!! rear axle locks up momentarily, nearly putting my wife and I into the windshield.
WTF!!!
Couple miles later, same thing, this time I get kicked 2' across the center line. Wife is freaking out. We pull over, turn around and baby it back home.
Take it to a shop and they have no clue. No warning lights. Nothing appears wrong.
Two days later I get a carfax email about this:
Recall# N242454440
So now I get to wait for GM to figure out a fix for my, not even registered yet, $40K death trap.
 
  • Like
Reactions: kidturbo and N2BRK

kidturbo

Piston Tester
Jul 21, 2010
2,532
1,357
113
Somewhere On The Ohio
www.marinemods.us

What Should Customers Do?

  • For Current Owners: While there is no immediate fix for the issue, current owners should remain aware of their vehicle’s behavior, especially if they experience harsh shifting.

Well shifting you 2 lanes while towing a camper certainly qualifies as Harsh in my book..
Thanks for the alert.
 

BradN

New member
Jul 29, 2024
4
2
3
Los Alamos, NM

What Should Customers Do?

  • For Current Owners: While there is no immediate fix for the issue, current owners should remain aware of their vehicle’s behavior, especially if they experience harsh shifting.

Well shifting you 2 lanes while towing a camper certainly qualifies as Harsh in my book..
Thanks for the alert.

Yeah, I'd say we're pretty damn aware of our vehicle's behavior. How about GM getting aware of fixing it.
 

Cougar281

Well-known member
Sep 11, 2006
1,806
249
63
St Louis, MO
So what's different about the transmission in the half tons vs the 10 speed found in other vehicles like my CT6 and the CT5 & CT4? I believe all of the 10L's are essentially the same. What did they change to create this problem, or is it likely to affect ALL vehicles with a 10 speed?
 

BradN

New member
Jul 29, 2024
4
2
3
Los Alamos, NM
I fully concur with your assessment. There's a reason valve spools never have o-rings. Plus the fact that I'm sure it's the housing that's worn, not the spools. That means the spool to body clearance is bad which puts o-rings at further risk.
I assume (OK, I hope) the GM fix involves replacing that upper valve body section. I can't imagine anything else will work.
 

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
3,492
472
83
Central OH
Sonnax makes a lot of oversized valves and reamers for valve bodies but not really anything for the 10L1000 other than TCC parts. I imagine if issues persist and GM can't remedy it or keep up with replacement valve bodies then Sonnax will more than likely start.
 

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
15,607
1,862
113
Mid Michigan
Question: Do you guys think that fluid is leaking around the valves, causing some sort of transmission tie-up?

This is the kind of problem that Mike always used to be able to solve. Dang it.
 

kidturbo

Piston Tester
Jul 21, 2010
2,532
1,357
113
Somewhere On The Ohio
www.marinemods.us
My buddy left town for the weekend, so this seal reveal party is back under the bench until I return. :cry:

I'm guessing it engaging two gears/clutches like a trans brake. Which if so, would be very bad.

Or it's detecting a slip and going into a limp mode, which might be 2nd gear. Which at 80, would feel like you locked up..
 
  • Like
Reactions: 2004LB7

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
15,607
1,862
113
Mid Michigan
Is the same transmission used in other GM cars, not just trucks? If so, are those vehicles having the same issues? If not, whats different about the truck trans vs the car trans that could be contributing? Just me and my uninformed ideas again....
 

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
3,492
472
83
Central OH
Question: Do you guys think that fluid is leaking around the valves, causing some sort of transmission tie-up?

This is the kind of problem that Mike always used to be able to solve. Dang it.
Cross leaks in the valve body can definitely cause serious damage, but without knowing exactly where the wear areas and which valves apply what I'm just guessing. I've never seen it cause the rear tires suddenly lock up, but there's been plenty of valve body complaints on the 10L
 

Mikey52

Active member
Sep 20, 2018
129
32
28
According to video, the wheels didn't lock up. Just that at high speed, it shifts into 2nd gear. It would appear that they locked up, but 65+ mph with torque converter locked, I imagine a lot of screeching would take place.