6L80 What to do?

[nomadw8]

6L80 What to do?

I have a 2014 Silverado with 130K. It has the 4.3 & the 6L80.

I've changed oil & tranny fluid per maintenance sked. No mods other than Active Fuel Management disabler via OBD plug in module. Always has run & shifted fine. 

Recently, on a long trip, the tranny overheated. 240 deg+ for a brief time. It had never done that before. I drive very conservatively. Check engine light.came on & showed P0700 (transmission control system). Tranny still shifts OK after the overheat episode. Maybe a few slighly harder than normal shifts occasionally  but not bad.

When I reached my destination, I checked the  fluid. It was dark & had a bad smell.
I called my local mechanic & he says it's just a matter of time before it failed & quoted me $4,300 to fix. I'm  a senior citizen on a fixed income and can't afford the $4,300.

My questions:
What can be done other than a new tranny.
Is a fluid change advised? What about the filter?
Would a tranny thermostat bypass/delete be wise/helpful.

or

Should I junk it?

Grateful for any help/advice.

[newdude]

45 minutes ago, nomadw8 said:

6L80 What to do?

I have a 2014 Silverado with 130K. It has the 4.3 & the 6L80.

I've changed oil & tranny fluid per maintenance sked. No mods other than Active Fuel Management disabler via OBD plug in module. Always has run & shifted fine. 

Recently, on a long trip, the tranny overheated. 240 deg+ for a brief time. It had never done that before. I drive very conservatively. Check engine light.came on & showed P0700 (transmission control system). Tranny still shifts OK after the overheat episode. Maybe a few slighly harder than normal shifts occasionally  but not bad.

When I reached my destination, I checked the  fluid. It was dark & had a bad smell.
I called my local mechanic & he says it's just a matter of time before it failed & quoted me $4,300 to fix. I'm  a senior citizen on a fixed income and can't afford the $4,300.

My questions:
What can be done other than a new tranny.
Is a fluid change advised? What about the filter?
Would a tranny thermostat bypass/delete be wise/helpful.

or

Should I junk it?

Grateful for any help/advice.
 

 

 

The transmission is RIP.  Torque converter is going or gone which is damaging the fluid pump and causing the overheat.  

 

Fluid change and bypass, its too late for that now.  Put the new lower temp thermostat or a bypass kit on after you install a new transmission.

 

Or...cut your losses and sell the truck/trade it in.  

[Black02Silverado]

9 minutes ago, newdude said:

 

 

The transmission is RIP.  Torque converter is going or gone which is damaging the fluid pump and causing the overheat.  

 

Fluid change and bypass, its too late for that now.  Put the new lower temp thermostat or a bypass kit on after you install a new transmission.

 

Or...cut your losses and sell the truck/trade it in.  

This pretty much covers it.  I understand you are on a fixed income but the cost to rebuild it is going to way less than finding another reliable vehicle I would think.

[nomadw8]

Right now it shifts pretty good. Usually smooth shifts with an occasional slightly harder shift. 

 

How long do  you think I have till the tranny quits on me.

[diyer2]

No one can predict that, but if you l need an answer Aug. 12 at 8am. 

[rav3]

Check the fluid again & see if u can see any 'sparkle' stuff in the fluid.  That would/ could be an indicator of possible torque converter or pump damage. If it were me, I'd suck the tranny fluid out of fill tube & replace it & see if it made any improvements. Do cheap fixes 1st, you can always to the expensive ones later

[CamGTP]

Use a credit card to pay the bill, if you make decent payments on it every month you won't rack up tons of interest on the balance.

[Grumpy Bear]

16 hours ago, nomadw8 said:

6L80 What to do?

I have a 2014 Silverado with 130K. It has the 4.3 & the 6L80.

I've changed oil & tranny fluid per maintenance sked. No mods other than Active Fuel Management disabler via OBD plug in module. Always has run & shifted fine. 

Recently, on a long trip, the tranny overheated. 240 deg+ for a brief time. It had never done that before. I drive very conservatively. Check engine light.came on & showed P0700 (transmission control system). Tranny still shifts OK after the overheat episode. Maybe a few slighly harder than normal shifts occasionally  but not bad.

When I reached my destination, I checked the  fluid. It was dark & had a bad smell.
I called my local mechanic & he says it's just a matter of time before it failed & quoted me $4,300 to fix. I'm  a senior citizen on a fixed income and can't afford the $4,300.

My questions:
What can be done other than a new tranny.
Is a fluid change advised? What about the filter?
Would a tranny thermostat bypass/delete be wise/helpful.

or

Should I junk it?

Grateful for any help/advice.

 

Did you change fluids on the severe schedule of 45K or 90K normal? There is no normal. 

 

Your fluid is burnt. Change it. Drop and fill a few times but do not flush it. 

 

It's rare for a V6 Converter to fail but not impossible. Guy on this list has had two fail. He's also the only one I know of.  It's common for fluid to be run well past its usefulness, cause a slip and toss a code. The factory thermostat is a transmission fluid killer. Flip the pill. 

 

Mine would sneak into the 240/260F+ range before I did the pill flip on a hot day. The P0700 code is a generic fault. Could be anything and you need to find someone willing to diagnose it instead of looking at you like a porkchop. 

 

Did you hurt it? Maybe. Is it fatal?  But it will be if you don't change the fluid and cool it off. 

 

You hear hooves? Think horses, not Unicorns. If I'm wrong, you are out nothing but a fluid change. If it's toast, it's toast. You can't hurt it changing fluid. Okay, unless you don't fill it correctly. 

 

 

Edited August 3, 2024 by Grumpy Bear

[nomadw8]

Update:

 

It's been two months since the 6L80 overheated. 

Since then I've changed the tranny fluid twice, installed a SUPERIOR Solutions thermostat bypass & added 20 oz of Lucas Oil transmission fix with the last fluid change.

 

The SUPERIOR Solutions thermostat bypass fixed the overheating problem. It lowered the temps I'm seeing by 35-45 degrees F. I no longer see high Temps. Usually max of 165-170 F on hot days. I saw 215 -220 before I did the bypass. 

 

The truck has 132K on it. Engine runs perfectly & tranny still shifts OK. 

 

Will it last? Who knows.

 

 

[rav3]

You've done the right stuff, IMO. Since it overheated, & the transmission holds 10 quarts & you probably removed about 4 qts per change, I'd do it again at next oil change. It's easier to suck it out the dip tube than dropping the pan, imo. No to difficult from topside.

[nomadw8]

I installed the  SUPERIOR Solutions thermostat bypass last September which fixed my overheating problem. It lowered the tranny temp. I began seeing  max of 165-170 F. I saw 215 -220 before I did the bypass.

 

Suddenly I'm  seeing 240- 250 F. What could be possibly causing this sudden increase?

 

The truck has 136K on it now. Engine still runs perfectly & tranny still shifts OK. 

[CamGTP]

If it's that high even with a cooler it's probably slipping internally if I was guessing.