Help identify an issue - Skipping/Shaking

1SLOW1500 · June 5, 2019

Very happy to hear that. I would be interested in hearing what trans temps you see as normal driving after the mod. Thanks for the post.

Ozer · June 14, 2019

On 6/5/2019 at 10:43 AM, 1SLOW1500 said:

Very happy to hear that. I would be interested in hearing what trans temps you see as normal driving after the mod. Thanks for the post.

Its been a week, truck is running great. Trans is feeling strong and doesnt skip a beat.

Even on a mid 80s hot day going home with traffic i got 170 max. Normal temps are at most 145 on average.

I also used a bottle of Techron fuel injector cleaner and i swear no more misfires.

I was surprised it worked. I will be using it every 5k miles going forward.

madsen203 · June 14, 2019

Thermostat doesn't prevent transmission from getting hot--rather the opposite--it allows it to get to operating temperature where it is most efficient and easier on the syncros, etc.

That's a great price for a new trans. Can't beat that.

If mine started acting up, I'd take it to the dealer and trade it in ASAP. The loss on trade in is probably less than the trans itself and then I can start fresh. So long as I can limp to the dealer and clear the code so it passes inspection, let GM have at it.

1SLOW1500 · June 14, 2019

Thermostat doesn't prevent transmission from getting hot--rather the opposite--it allows it to get to operating temperature where it is most efficient and easier on the syncros, etc.

That's a great price for a new trans. Can't beat that.

If mine started acting up, I'd take it to the dealer and trade it in ASAP. The loss on trade in is probably less than the trans itself and then I can start fresh. So long as I can limp to the dealer and clear the code so it passes inspection, let GM have at it.

You are right but many people see high operating temps 200*+. The big power vehicles have no thermostat and big single or dual coolers and max temp of never more than 180* but operating of 150*. My truck gets to 120 in first few miles. And engine temp of 180 in first mile. The engine brake that others talk of shows in data a 20 degree increase in temp. So to think a operating of 150 and one brake and in that 2 seconds you are at 170+ fan on and trying to cool. Issue is the stock thermostats is too hight for anyone but maybe a eskimo.
Remember if you read the official 6l80e bulletins it says after flush/fill to start engine and shift to neutral the pump will cycle the fuild around. But how can it flush the lines of that fluid? Where If there is a lower thermostat or no stat the fuild is always cooling and filtering.
If i had a thermostat i would want a 120* warm but out safe for my other controls to work and at lights I would know the fluid cooling.

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madsen203 · June 14, 2019

1 hour ago, 1SLOW1500 said:

You are right but many people see high operating temps 200*+. The big power vehicles have no thermostat and big single or dual coolers and max temp of never more than 180* but operating of 150*. My truck gets to 120 in first few miles. And engine temp of 180 in first mile. The engine brake that others talk of shows in data a 20 degree increase in temp. So to think a operating of 150 and one brake and in that 2 seconds you are at 170+ fan on and trying to cool. Issue is the stock thermostats is too hight for anyone but maybe a eskimo.
Remember if you read the official 6l80e bulletins it says after flush/fill to start engine and shift to neutral the pump will cycle the fuild around. But how can it flush the lines of that fluid? Where If there is a lower thermostat or no stat the fuild is always cooling and filtering.
If i had a thermostat i would want a 120* warm but out safe for my other controls to work and at lights I would know the fluid cooling.

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If you're building that much heat in the transmission, having no thermostat isn't going to prevent the temps from going above 180. 180 is the normal operating temperature and when the t-stat is fully open. Now having no thermostat is likely to cause more wear and stress on the transmission as it is running with fluid that hasn't met its target viscosity. This means reduction in MPG, more wear on the internals, and likely to cause blockages and other problems as it isn't warming up enough to burn off moisture build up/accumulation. It is also normal to run regularly around 155-165 as the thermostat is partially open but not wide open until 180. That does not mean that normally running temperature is 160--that just means the thermostat hasn't reached it's target temperature yet--much like the t-stat of the motor running at 210*.

Having a dual cooler with a T-stat is a better platform--the transmission can run at normal operating temperature but can keep cool when the heat build up exceeds what a single cooler would be able to manage. The fluid specified is capable of the higher temps than just 180* and the truck would warn if there is an overheating problem--much like the coolant that runs through the motor. The motor runs at 210 with the t-stat wide open but can comfortably run at 10% above that temperature as well and still be within normal operating spec without any long term concerns.

If you're hammering on the trans to the point where it is constantly running near the peak of its operating confines, you're using the wrong truck for the project. That, or you need to subsidize the cooling system with additional oil coolers. Not having the thermostat is outright dumb and ignorant.

1SLOW1500 · June 14, 2019

51 minutes ago, madsen203 said:

If you're building that much heat in the transmission, having no thermostat isn't going to prevent the temps from going above 180. 180 is the normal operating temperature and when the t-stat is fully open. Now having no thermostat is likely to cause more wear and stress on the transmission as it is running with fluid that hasn't met its target viscosity. This means reduction in MPG, more wear on the internals, and likely to cause blockages and other problems as it isn't warming up enough to burn off moisture build up/accumulation. It is also normal to run regularly around 155-165 as the thermostat is partially open but not wide open until 180. That does not mean that normally running temperature is 160--that just means the thermostat hasn't reached it's target temperature yet--much like the t-stat of the motor running at 210*.

Having a dual cooler with a T-stat is a better platform--the transmission can run at normal operating temperature but can keep cool when the heat build up exceeds what a single cooler would be able to manage. The fluid specified is capable of the higher temps than just 180* and the truck would warn if there is an overheating problem--much like the coolant that runs through the motor. The motor runs at 210 with the t-stat wide open but can comfortably run at 10% above that temperature as well and still be within normal operating spec without any long term concerns.

If you're hammering on the trans to the point where it is constantly running near the peak of its operating confines, you're using the wrong truck for the project. That, or you need to subsidize the cooling system with additional oil coolers. Not having the thermostat is outright dumb and ignorant.

Sorry but the the pros as well as GM disagree with you. this is not what my emails and the specs from GM say on D6 or these trans. also what you say about running 210 if it was 10 over it is still fine but a light on dash. In fact we are going over some of that it in the tune with the "hot" table and what we can set that to also. but for a "new" oil type to be spec and to say then it can are two different things. But no d6 break down vs temp rate state other wise. also if you follow so of the big power builds, where guys are using a 6l80 or 6l90 and have $10,000 trans you will see they make a goal of 150ish temps MAX 180.

As far as engine coolant that is different there are tuning table that change everything based on a ect temp. So this is important. I need 180*. As I said a minimum operational temp I agree with a statement like but there is a point of a compromise to the fluid and the wear and protection of parts.

If you would like I will post the articles and emails as well as the(If I can ) tune blog on trans tuning. Even the Circle D article for hot rod talks of this. as well as AMSOIL did a video on it in a stock truck. How many people having trouble with there 6speeds and 8 speeds. I will trust the people that have made then work as well as the ones that engineer and test them.

1SLOW1500 · June 14, 2019

Read this.

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madsen203 · June 14, 2019

16 minutes ago, 1SLOW1500 said:

Read this.

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"ideal" is 180. Much like ideal of engine temp is 210. Doesn't mean running it over that temp is going to cause problems. Sure, fluid will sheer sooner and have a shorter lifespan--it's a consumable, replace it after X miles.

What is this body of text from? Something advertising additional products from their company? I trust an engineer from GM before someone selling me a product to help with a problem that isn't really there. Failure in these transmission is due to a 1:50,000 chance--most likely due to manufacturing. Probably a 1:1,000,000 chance it's due to over heating. Again, if the load you're putting on it is creating that much heat, you have the wrong tool for the job. These are half ton, grocery getters, weekend home depot runners. Sure, they can pull 10K lbs, but in reality, they are not designed for it long term. That's what the HD's and real/full size trucks are for. Yes, you can make the truck exceed capacity or run at it's peak capacity, but you're just putting band-aids on problems that shouldn't have been there in the first place if used appropriately.

These are not race cars, these are not off road rigs, these are definitely not heavy duty or full size trucks. If you're creating that much heat to damage a transmission, you're using it a manner that exceeds GM's target market for these vehicles.

1SLOW1500 · June 15, 2019

that is from Circle D invoice. that is why I blocked out the top and bottom.

I just checked 5 sites and every single one it the same info heat kills stall under 200 or under 180. and cooler bypass it. they run hot.......

Oh also interesting gm changed design from trans cooler lines into the radiator to not in the radiator and in stead in the AC condenser(like mine) seams they knew the heat was a issue. But I am checking with my GM contacts on that one. also says 2014+ they stated adding the thermostat.

Can't add the other sites unless you are a member.

Oh this cart seems about right as Amsoil video shows 40k miles all stock yukon with burnt oil and debris. and the few Gm-truck guys had over 50k miles and trans issues. so by this chart us 200-210* guys need changes every 25-30k miles. And how many people are doing that????