Keith,

Good move. But they will not take care of a repair if the vehicle has been modified. With today's complex systems, its certainly worth a look at the OEM extended warranty plans.

No so on campers, since turn around on repairs makes the warranty mostly unusable.

Jim

Snowmobile.......

I spoke to my transmission guy before getting the bypass from him. I trust him completely and the reason for elevated temps is for the efficiency boost that thinner oils have, however the trade off is clutch life. Thinner oils have less parasitic drag but also provide less lubrication, and are less efficient in the torque converter. When towing, the temps do get higher, but I have noticed that the trans will eventually reach a happy spot in the temps. The bad thing with the thermostat is it creates a restriction in the cooler flow path when its really needed.

Joseph,

Its no secret that thinner and better quality fluids are used today to reduce friction. My truck takes 0W-20 engine oil. But I will not be using 10W-40 because I tow for example. I will also leave my engine running at 210F. I will not install a 180F thermostat.
I will use what is recommended in the owners manual and leave my truck as designed.
Haver your transmission guy to apply for an engineering position at GM so he can educate them in transmission durability studies.

Jim

Per a Marc from Keeping your Daydream, he likes the manual regen for:

• When he is getting close to needing a regen
• He's got a long trek lined up

In that scenario, he'll manually trigger it early so it has a chance to go thorough the entire cycle when he's making a long drive.

Jim,

My transmission guy is technically retired now, but he did have 1 or 2 of the new allison 10 speeds in his possession before they were put into trucks. He was also in close contact with several people in side GM and Allison to discuss what he was seeing.

From my dealings with him and several other sources of information, the new transmissions are built for economy trying to squeeze every last % point possible. Thinner oils helped with a bringing the numbers they needed. For towing, I will always err on the side of cooler. Engine Oil I do run the viscosity that the MFG calls for and I do run the approved automatic transmission specific fluid specified. Again I err on the side of trying to maintain engine temp as close to thermostat full open as possible because of emissions and economy.

Everyone has the right to follow what they feel is correct. Down here pulling trailers in the 100F + heat, transmission heat soak is a big deal as the coolers cannot remove enough heat fast enough at times.

I did notice pulling up through Denver, then back down through Colorado Springs on I25, then down to Las Vegas, NM the transmission temps would settle around the 180F mark. With the thermostat installed before it would hit 190F unloaded. Pulling my 12' trailer with the Kubota SXS this would jump to over 200F. With that being said, I felt it was not worth risking an oil failure die to excessive heat. Again, my truck, my choice based on input from a well trusted source.

Keith, keep us updated on what you find pulling.

Joseph

Will do I just need to learn all the menus option on the display. I have the trans temp gauge visible, but was watching some videos on how to customize the gauge cluster behind the steering wheel. I still get confused on the naming system between that one behind the steering wheel and the center 12" display. Owners manual says I should be able to customize what I see, so something new to learn. Was busy irrigating my hay fields today and assembling my B&W hitch between moving water.

Good day until the 40 mph winds hit and the smoke and dust moved in from all the fires around us. Tomorrow AM (while it is cool) I will set the hitch in place and do a trial fit.

If anyone knows of good videos on customizing the display, please post.

I am leaving the truck stock. Why mess with perfection
Keith

Joseph,

I've spent years in the dyno cells at GM, Chrysler and in another role before that, the job put me in every major dyno cell in the country. I've seen the durability testing that goes on as well as the emissions tests in order to achieve good fuel economy. I have personally tested HD trucks out west and up stovepipe pass out of death valley at 125F where we monitored transmission and engine oil temps to be certain we were not at risk of degrading the fluid while towing at max capacity. So trust me, your OK in TX. There is really no way you will convince me that after witnessing the millions of dollars that is spent in development and durability testing to bolt on an aftermarket kit to modify transmission temperatures without the same level of testing and durability testing.
You are free to modify your truck but my advice would be to leave it alone.

Jim

I got my clean star white truck dirty!

Second long break in drive of 390 miles give or take/ Averaged 19.6 mpg. Now have 639.5miles on "Hal". I did have a couple of issues pop up, but it probably a learning curve.

Left about 9AM Drove US 160 East from Durango to Pagosa Springs, then 84 south to Chama . It was in this area I got a driver alert warning. Road is very uneven and rutted so truck wandered a bit. We then continued south to Espanola. in this stretch I again got a driver alert warning as road was very uneven and truck seemed to want to wander. We then caught 30 down to 502 and then west to Las Alamos. That place is nuts with poor road markings. Had to use the dash map to get us out of there as I did not want to pay a toll to head towards Cuba over on US 550. We found 501 to 4 and finally get out of there. Talk about security measures along that road. Then took 4 through Vallas Caldera National Preserve - stunning beautiful drive. This is a slow speed tight hair pin two lane road. I had truck in normal driving mode and noticed a slit shifting hesitation / bogging issue between 3rd and 6th as we sped up and down going up the mountain.
As we had programed Cuba the map adviser tried to get me to take a two tract path through the basin - not good, and wanted me to take a second gravel road through the Preserve that was not on our Atlas map, so we turned her off. Then SWMBO saw 126 on the atlas map we have - looked good, except she did not see the 16 miles of unimproved Forrest service road over the pass. I discovered that when I saw a sign 20 miles in, but decided to go on. Do not take this road - especially if it has rained. We were lucky it had just been graded but was still very narrow (one lane in many areas), rough, sandy, muddy and rocky. Averaged about 10 mph and again noticed a bogging in the lower gears in normal driving mode. I shifted into TH mode and things seemed to improve a little. We finally got into Cuba and headed north towards Durango on US 550 - 70 mph 4 lane. The truck wondering on the good pavement went away and it would drive true and straight if I took my hands off the wheel. Got back to Durango around 7:15 PM No additional driver alert warnings after the second one.

This morning I found and deactivated the driver alert. I also noticed what appears to be some feathering on the outside front tires. Ill swing by Discount Tire as they are close to where I need to go today to see if my expert there can detect anything.

Now to clean my truck. I am going to use Meguiars Ultimate Wash & Wax.

I am amazed at the fuel mileage I am getting. My old 04 6.0 Dully would have been in the 10 range even empty. If you have any thought on the shifting concerns, please let me know.

Thanks
Keith

I have a 2020 F-350 Lariat DRW with the 10 speed transmission and do remember thinking I was having transmission issues for first couple thousand miles. In talking to the dealer they said the transmission was “learning how I drive”, the truck now has 20,000 miles and seems to operate flawlessly, just had it and our 375RES over berthoud pass last weekend and it was amazing!! That was my first mountain pass with the 375RES and this truck. Cant is say enough good things about how well it tows!!

Thanks Scott
With all the varied driving I have been doing ( recommended for break in ) I was wondering about the learning curve. It good to know it's ME learning here

Thanks
Keith

Keith, I suggest https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1 or something similar after you get through with the wash / wax. It will help extend the between wax intervals, or possibly eliminate. On GM diesel forum, one of the hot shot drivers was using it on his tow rig and could get several of the truck washes out of it before it would show signs of letting up. I know I did the trailer and the truck. Makes washing and cleaning so much easier.