: Recall # N242454440 MOMENTARY REAR WHEEL LOCK-UP

[BradN]

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.

 

[kidturbo]

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.

 

[NC-smokinlmm]

That’s some straight bullshit right there.

 

[BradN]

​

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.

 

[gassux]

i saw it on fab rats youtube I'm shocked that GM is doing a recall

Source: https://www.youtube.com/watch?v=NvQ3fRX7swQ

 

[Cougar281]

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]

Recall Info Link
Lists models affected

 

[Chevy1925]

i saw it on fab rats youtube I'm shocked that GM is doing a recall

Source: https://www.youtube.com/watch?v=NvQ3fRX7swQ

Yeah I don’t like that fix. O-rings on a valve like that, that moves back and forth I feel is just asking for o-ring material to go into the vb or be a temp fix at best.

 

[BradN]

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.

 

[kidturbo]

Just so happen to have a used 10L80/90 something valve body under my desk. Never been out the box, no idea what year/model.
Maybe we should crack it open ??

 

[2004LB7]

Just so happen to have a used 10L80/90 something valve body under my desk. Never been out the box, no idea what year/model.
Maybe we should crack it open ??


View attachment 126813

Do it, do it, do it!!!!

If it is a worn bore, I wonder if you could run a reamer down it an then press a sleeve in.

 

[TheBac]

So make this Project #3 for Kidturbo?

 

[kidturbo]

So make this Project #3 for Kidturbo?

#4 maybe, I lost count.

I'm heading out of town for a couple weeks, but gonna try and tear this apart with my transmission master tech buddy tomorrow.
Which holes we need to photograph ??

 

[N2BRK]

“Which holes we need to photograph ??”

Some days it’s just too easy. Giggidy.

I have nothing substantive to offer in this thread

 

[PureHybrid]

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]

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]

My buddy left town for the weekend, so this seal reveal party is back under the bench until I return.

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..

 

[TheBac]

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]

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]

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.