6L80E thermostat delete sure-cool cooler kit

yourleftnut1 · May 21, 2021

I have no idea what the stall speed for the torque converter is on mine. Now that you mentioned the issue with V8's only, I have never seen a single 4.3L on those 100's of work orders at work. Each rebuild comes with a work order that specifies the engine it is used for and I've seen only V8's. lol.. All torque converters are replaced with each rebuild. Maybe I won't have to replaced the TC on my truck after all. fingers crossed.

We have a torque converter rebuilding department too. When I get the chance, I Will check how often the 4.3 gets rebuild. i seriously do not remember seeing any 4.3's coming through.

Glad I didn't get the Z71 V8 version then. I don't do a lot of towing, so the 4.3L fit the bill. Heaviest tow was a 500lb (probably less) jon boat lol.. dropping the trans pan and changing out the spark plugs seem a lot easier on the V6 vs V8 too..

Edited May 21, 2021 by yourleftnut1

Yotaman · May 21, 2021

6 hours ago, yourleftnut1 said:

I love my silverado. 70k miles and no issues so far, but I must say, the transmission seems like the weakest link. I haven't messed with other auto manufacturer's transmission at work, but seems like GM took a short cut on the 4L60E's and 6L80/90's. Almost all the internals could be upgraded to a better part and it doesn't cost much more. Don't know what the previous owners used their trucks for, but we would get transmissions in with cracked drum pistons, cracked clutch plates, and many other things. We always replaced those failed parts using sonnax after market parts..

seems like the torque converter on my truck will eventually fail too. the good part is, I can rebuild my entire transmission in my garage and borrow tools from work to work on it over the weekend. i could even take it to work and have it test run on a dyno before installation.

Where do you live ? Asking for a friend

Grumpy Bear · May 21, 2021

4 hours ago, Yotaman said:

Where do you live ? Asking for a friend

Me too.

Grumpy Bear · May 21, 2021

10 hours ago, yourleftnut1 said:

I have no idea what the stall speed for the torque converter is on mine. Now that you mentioned the issue with V8's only, I have never seen a single 4.3L on those 100's of work orders at work. Each rebuild comes with a work order that specifies the engine it is used for and I've seen only V8's. lol.. All torque converters are replaced with each rebuild. Maybe I won't have to replaced the TC on my truck after all. fingers crossed.

We have a torque converter rebuilding department too. When I get the chance, I Will check how often the 4.3 gets rebuild. i seriously do not remember seeing any 4.3's coming through.

Glad I didn't get the Z71 V8 version then. I don't do a lot of towing, so the 4.3L fit the bill. Heaviest tow was a 500lb (probably less) jon boat lol.. dropping the trans pan and changing out the spark plugs seem a lot easier on the V6 vs V8 too..

Now isn't that interesting!

Can you find out if they use the SONNAX clutch in your 6L80/90 V8 Converter rebuilds?

Someone here was asking for such a source just a few days ago.

A fella I know in Georgia that rebuilds transmissions told me once that the only V6 6L80 he ever had in his shop was from a salvage truck. Again, very interesting.

Ricardo torrento · August 16, 2021

On 3/9/2020 at 11:15 AM, Dmitri Mendeleev said:

Just got this kit installed on my Tahoe at the dealership yesterday (2018 LS 4WD max tow). Will be watching the trans temperatures as the weather warms up.

Ricardo torrento · August 16, 2021

Hello I was wondering if you can provide an update.? How did it do while towing?

Fridayhell · December 3, 2021

here is another solution https://lincodieselperformance.com/shop/ols/products/ldp-l5p-trans-cooler-bypass-valve.

BlaineBug · December 8, 2021

On 12/3/2021 at 10:34 AM, Fridayhell said:

here is another solution https://lincodieselperformance.com/shop/ols/products/ldp-l5p-trans-cooler-bypass-valve.

That looks to be a drop-in replacement for the PILL that's length is equal to the thermostatic PILL when it is fully extended (which means full flow to coolers.) If you've ever opened up the thermostat bypass assembly you will know that the PILL is supported by a spring at both ends which allows it to recirculate flow back to the transmission in the event that a cooler line ever becomes clogged. This is a safer alternative than simply flipping the pill. OR another safe alternative is tapping and plugging the assembly and not reinstalling a pill at all.

OR in my case I recently installed GM's newly revised thermostat bypass assembly which contains a lower temperature thermostat.

Grumpy Bear · December 8, 2021

2 hours ago, BlaineBug said:

If you've ever opened up the thermostat bypass assembly you will know that the PILL is supported by a spring at both ends which allows it to recirculate flow back to the transmission in the event that a cooler line ever becomes clogged. This is a safer alternative than simply flipping the pill. OR another safe alternative is tapping and plugging the assembly and not reinstalling a pill at all.

OEM works just like a water thermostat working against that spring. There is no pressure relief bypass. The Superior Transmission STL010 6L80 Sure-Cool System will bypass on pressure. A marketing gimmick.

Tapping the plugging is identical to a pill flip in response to pressure. You block the return path. It's also identical to the absence of any thermal device as was the case for decades. Do ya hear of allot of blocked cooler related pump/transmission failures? Nada!

Irrational fear being monetized

With the pill flipped, body drilled and tapped or STL010 kit installed it will act like every automatic pre 2014.

THINK

ATF flowing through a radiator tank of hot water.

There is a floor as to how cold the fluid will get when being heated by coolant.

Fridayhell · December 15, 2021

.

Edited December 15, 2021 by Fridayhell

Grumpy Bear · December 15, 2021

On 12/3/2021 at 10:34 AM, Fridayhell said:

here is another solution https://lincodieselperformance.com/shop/ols/products/ldp-l5p-trans-cooler-bypass-valve.

From their site:

2017-19 GM trucks with Allison transmissions (AND 2014- up GM gas trucks and suvs with 6 OR 8 speed automatic trans) utilize an auxiliary transmission cooler thermal bypass valve to control fluid flow to the auxiliary cooler. The factory valve is restrictive and does not allow sufficient flow to the auxiliary cooler causing higher trans fluid temps especially on trucks with increased line pressure from trans tuning or a built trans. In testing on our shop L5P we saw trans temps in excess of 215 degrees after installing one of our built units. This lead to the design of the LDP L5P trans cooler bypass valve. We have seen up to 50 degree temp drops even on stock trucks and have had customers reporting 60 degree temp drops! Our design allows you to install the factory thermostatic valve for cold weather operation to maintain optimal fluid temp year round. Install time is less than 10 minutes- see attached video.

Isn't that interesting?

One could even remove the bypass valve :

Then add a lower temperature unit such as:

https://www.improvedracing.com/high-flow-engine-transmission-oil-cooler-thermostat.html

Might like that better than twice a year swaps for those whose fluid does not use the radiator as a cooler/heater. This one you get to choose a pretty liberal number of temperature options with full knowledge of operating conditions published in table form.

There seem to be allot of factory layouts for cooling that all have unique needs. This thread brought that to light well.

Edited December 15, 2021 by Grumpy Bear