Considering how GM screwed us with the oil, what about the ATF?

[jfoj]

For some reason the Diesel temps with the external transmission thermostat run higher than the gasoline engines with the internal thermostat. Glad to hear that GM revised the diesel external thermostat.

I don't think my gas transmission temperature everyone higher than 165 in the summer and stop and go traffic. I did the next gen valve body update and pulled the thermostat out of my unit and it runs a little bit cooler not significantly. I also have the $300 towing package which I'm not sure what that includes.

 

[Plimbob]

For some reason the Diesel temps with the external transmission thermostat run higher than the gasoline engines with the internal thermostat. Glad to hear that GM revised the diesel external thermostat.

I don't think my gas transmission temperature everyone higher than 165 in the summer and stop and go traffic. I did the next gen valve body update and pulled the thermostat out of my unit and it runs a little bit cooler not significantly. I also have the $300 towing package which I'm not sure what that includes.

How well did the NextGen valve body improve shifting?

 

[jfoj]

How well did the NextGen valve body improve shifting?

Overall very happy with the results. Less hunting and slightly firmer and crisper shifts. Not harsh but noticable. I have a big thread on here about it. Not a hard job if you have some skills, but the gasoline engines are a PITA as you need to drop the exhaust from the manifolds , just lower about 3" to get the trans pan out. The 6 cylinder Diesel this is not a problem. The one thing on the Diesel there needs to be clarification about the valve body thermostat plug, I do not think it needs to be messed with on a Diesel, however, a few folks had to machine the original plug in the valve body to flip it. Given the Diesel has an external thermostat anyway, I do not think the plug in the valve body where the gasoline thermostat is located needs to be messed with. But best to get an answer from NextGen about this.

 

[Vector]

Overall very happy with the results. Less hunting and slightly firmer and crisper shifts. Not harsh but noticable. I have a big thread on here about it. Not a hard job if you have some skills, but the gasoline engines are a PITA as you need to drop the exhaust from the manifolds , just lower about 3" to get the trans pan out. The 6 cylinder Diesel this is not a problem. The one thing on the Diesel there needs to be clarification about the valve body thermostat plug, I do not think it needs to be messed with on a Diesel, however, a few folks had to machine the original plug in the valve body to flip it. Given the Diesel has an external thermostat anyway, I do not think the plug in the valve body where the gasoline thermostat is located needs to be messed with. But best to get an answer from NextGen about this.

I am not sure about the bigger diesel, but I think this video is for the 3L
If I am not mistaken, I think this is a GM mechanic who has his own channel;

 

[jerry455]

Mobil 1 , black label, was the original fluid in the 8 speed. The Mobil 1, blue label, was the "upgrade" for the moisture absorption issue. I am not aware of GM using anything else for that trans.

 

[Burban22]

https://a.co/d/01cMDOVt

I ordered two boxes when I driveway flushed it. There’s several YouTube videos on how to flush yourself and check the level.

Pictured is the old black label but as long as the seller and shipper is Amazon, I’ve received the blue label, which is the new fluid. Flushed my 8L 90 in the driveway 100% at 20K miles. Did the cooler bypass my transmission used to run 200° normal driving and 215 when towing.

I now have 30 K miles on the truck. I never had any shutter issues, but after changing the fluid, it seems to have cleared up the sometimes clunky shifting in stop and go traffic.

Transmission now runs extremely cool usually 140 on the highway in 100° summer temps. It runs very cool in the winter doesn’t reach 100° sometimes but it doesn’t seem to affect anything.

Nice thing about doing the bypass, you can check the level anytime. You don’t have to wait for a thermostat to open.

 

[DontTaseMeBro]

Thanks for the replies thus far.

I have a bunch of questions and observations.

1) Is anyone running other ATF than AC Delco when they flushed/changed it, and if so what did you choose and why?

2) Has anyone done the bypass, as I am serious thinking about doing so with this unit?

Since we are on the subject of transmissions, I noticed that while there has been regular maintenance with this used ESV that I have bought, there is no indication that the transmission fluid and filter was ever changed like the manual calls for at 45k, and every 45k after that. Note it says fluid and filter.
I called several Cadillac dealers in my area to see how much they charged, and was shocked to hear prices all in the $800-$1,000 range.
Even more surprising was that these were not change the fluid and replace the filter, rather it was to flush the system while leaving the filter in.

Now I am aware from having spoken to transmission guys over the years that the filter media is not like an oil filter, and only designed to catch large particulates, and may help to save it from a catastrophic failure in those situations.
Thus most have said it is not important to change it, but it is very important to change the fluid.

3) My question is, if the service manual calls for a fluid and filter replacements every 45k, why are Cadillac dealers not changing both the fluid and filter as part of their routine transmission service?

4) Also, if you are still under warranty, and your transmission dumps out, is not having the filter changed as part of the transmission service going to void the warranty, considering that none of the Cadillac dealers service departments change the filter as part of their routine?

Additionally, one of the dealers said the flush would be about $600 which while expensive, would be less than the others by $200-$400 less.
However, the service manager pointed out that it "may" also need to be reprogrammed after the flush, and that would run an additional $200

5) Have any of you ever heard of a reprogramming of our transmissions after a service, be it a flush or change including the filter?

6) Since these transmissions are on other trucks be it the 6.2 or the 3L, can they do just as good a job on servicing the transmissions as the Cadillac dealers, maybe at a lower cost?

I can answer the question regarding using other fluid - I recently did a transmission fluid change @ just over 50k miles. Switched to Triax ULV ATF. 6 months in and transmission is very happy. Might be a placebo thing, but shifts are even smoother than before(weren’t rough to begin with).

Also, regarding programming - 100% BS. Just have to follow the typical procedure of filling it, getting the transmission up to temp, then opening the fill plug for a final fill or drain to get the level right. Lowest price quote I got after calling around a few dealerships was $900. No thanks.

 

[jfoj]

Read my comments above in post #23 about no need to get the transmission fluid to 175F.