6L80 (V8 Trans) experiences after power flush?

[Dart77]

For what it's worth, the torque converter is the number 1 source of 6L80 failure. It'll generally take out the pump along with it which is built into the bell housing.

For the ultimate in good feelings I would be visiting a tune shop to get the slip disabled at a minimum; and optionally disabling lock up in gears 1 through 4.

Ta for the advice - I knew the TC's were prone to failure in these and an auto trans rebuilder showed me one of the parts of the very early VE ones (06-07) which I think connected to the converter and which was fusion welded - and where the weld had cracked.

I will ask about the lockup getting disabled - didn't know that could be done. Thanks

 

[chrisp]

Ta for the advice - I knew the TC's were prone to failure in these and an auto trans rebuilder showed me one of the parts of the very early VE ones (06-07) which I think connected to the converter and which was fusion welded - and where the weld had cracked.

I will ask about the lockup getting disabled - didn't know that could be done. Thanks

The torque converter has the lock up clutch inside. (Some automatic transmissions have the lock up clutch pack within the trans itself). Apparently what can happen is that the clutch pack within the torque converter can shed material (I read somewhere that water in the transmission fluid exacerbates this?) and this material then damages the rest of the transmission.

I’m not sure if the friction material in the lock-up clutch is any different to that of the other clutch packs, so any clutch pack failure may have a similar result?

 

[hjtrbo]

I will ask about the lockup getting disabled - didn't know that could be done. Thanks

You probably meant it in your reply but I just wanted to reiterate. GM programs about 50rpm of constant TC slip to reduce NVH. This is what you want to ask about disabling. The stuff I said about disabling lock up in gears 1-4 is optional and down to personal preference in your situation. Sorry if I just told you how to suck eggs.

 

[lmoengnr]

You probably meant it in your reply but I just wanted to reiterate. GM programs about 50rpm of constant TC slip to reduce NVH. This is what you want to ask about disabling. The stuff I said about disabling lock up in gears 1-4 is optional and down to personal preference in your situation. Sorry if I just told you how to suck eggs.

Good info, thanks.

 

[Skylarking]

and the following series I’ve yet to watch…

 

[J_D 2.0]

GM programs about 50rpm of constant TC slip to reduce NVH make sure the TC lunches the transmission after the warranty period has ended.

Fixed it for you!

 

[J_D 2.0]

GM programs about 50rpm of constant TC slip to reduce NVH.

But seriously that’s makes it the absolute definition of a wear item and it should have a service interval! Who knew a TC clutch literally sees far more “action” than a manual transmission clutch, it’s slipping 100% of the time that it’s engaged FFS!

But if you told potential buyers that they would have to replace their torque converter every 100-150k kilometres they wouldn’t buy very many of your cars! So the obvious answer is to just keep mum about it and pretend the problem doesn’t exist!

 

[Skylarking]

But seriously that’s makes it the absolute definition of a wear item and it should have a service interval! Who knew a TC clutch literally sees far more “action” than a manual transmission clutch, it’s slipping 100% of the time that it’s engaged FFS!

But if you told potential buyers that they would have to replace their torque converter every 100-150k kilometres they wouldn’t buy very many of your cars! So the obvious answer is to just keep mum about it and pretend the problem doesn’t exist!

Oddly it’s not listed within the service schedule as a replaceable item or one that’s periodically checked….

So I’d say the TC clutch is up there with the in tank fuel filter as theses devices aren’t listed within the service schedule. Guess these items must thus be made of ground unicorn horns & pixie dust thus they never needs replacement or checking

As such I would argue that the fact the manufacturer doesn’t actually specify a service interval can actually be in the owners favour w.r.t. ACL. The owner can claim it’s not a serviceable item as it’s not listed in the service schedule thus shouldn’t fail so quickly. Or the owner can claim that had the item been listed as a serviceable item, the vehicle’s maintenance cost could have been better accessed prior to purchase but for the manufacturers omission/deception…

Whatever the case, it’s not of acceptable quality if a TC clutch fails at low kms taking the transmission with it… because of a defective design requiring almost constant slip and thus wear…

 

[chrisp]

Oddly it’s not listed within the service schedule as a replaceable item or one that’s periodically checked….

So I’d say the TC clutch is up there with the in tank fuel filter as theses devices aren’t listed within the service schedule. Guess these items must thus be made of ground unicorn horns & pixie dust thus they never needs replacement or checking

As such I would argue that the fact the manufacturer doesn’t actually specify a service interval can actually be in the owners favour w.r.t. ACL. The owner can claim it’s not a serviceable item as it’s not listed in the service schedule thus shouldn’t fail so quickly. Or the owner can claim that had the item been listed as a serviceable item, the vehicle’s maintenance cost could have been better accessed prior to purchase but for the manufacturers omission/deception…

Whatever the case, it’s not of acceptable quality if a TC clutch fails at low kms taking the transmission with it… because of a defective design requiring almost constant slip and thus wear…

I‘m not disagreeing with anything you have posted, but I do suspect that manufacturers use an unwritten acceptable life for a car. My suspicion is that it is 100,000 miles (or 160,000 km) and it’s based upon the idea of a car doing about 10,000 miles per year (16,000 km/year). The ’acceptable life’ is then about 10 years. I also suspect that cars would be designed to meet this 10-year life expectation. As an engineer, and knowing that things can vary considerably (such as how cars are used), I would guess that the calculations would be done on having parts last 20 years (200,000 miles, 320,000 km) to ensure that a large percentage make it to 160,000 km essentially trouble free.

So, if a clutch in a torque converter (which is totally unable to be serviced or inspected) lasts at least 160,000 km (and maybe even go to 320,000 km) the manufacturer can probably claim that it lasted the life of the car.

Also, if one takes a 10 year old car in for repairs, it’s not uncommon to hear the phrase ‘What do you expect? It’s a 10 year old car!’

 

[J_D 2.0]

I‘m not disagreeing with anything you have posted, but I do suspect that manufacturers use an unwritten acceptable life for a car. My suspicion is that it is 100,000 miles (or 160,000 km) and it’s based upon the idea of a car doing about 10,000 miles per year (16,000 km/year). The ’acceptable life’ is then about 10 years. I also suspect that cars would be designed to meet this 10-year life expectation. As an engineer, and knowing that things can vary considerably (such as how cars are used), I would guess that the calculations would be done on having parts last 20 years (200,000 miles, 320,000 km) to ensure that a large percentage make it to 160,000 km essentially trouble free.

So, if a clutch in a torque converter (which is totally unable to be serviced or inspected) lasts at least 160,000 km (and maybe even go to 320,000 km) the manufacturer can probably claim that it lasted the life of the car.

Also, if one takes a 10 year old car in for repairs, it’s not uncommon to hear the phrase ‘What do you expect? It’s a 10 year old car!’

Pretty sure I read somewhere that the design life of the 5L40E transmission was 200,000kms. I’d guess that you’re probably correct that they try and target around 160-200k kilometres as a general service life of a vehicle.

Realistically they could last a lot longer than that if components/assemblies were designed for maximum service life and manufacturers were honest about service requirements rather than their “sealed for life” crap.

As I’ve said elsewhere previously, if manufacturers and government were serious about global warming they would be aiming for (and governments regulating for) maximum service life instead of the “everything is disposable” shitfuckery we have now. Every piece of useless disposable shite not made is carbon emissions that is not created.