Is this transmission cooling setup normal/acceptable

[El Tigre]

The thermostat I mentioned from Improved Racing has no valve to impede flow. A passage between the to/from ports is open when cold,and closes when hot.Seems like some on here really like their built in cooler/warmer. Despite both ending up around the same temps anyway. Very imprecise in my opinion,but to each their own.

 

[Pinger]

The thermostat I mentioned from Improved Racing has no valve to impede flow. A passage between the to/from ports is open when cold,and closes when hot. Seems like some on here really like their built in cooler/warmer. Despite both ending up around the same temps anyway. Very imprecise in my opinion,but to each their own.

And, at the other side of the main radiator, the same thing is going on - with the engine oil....

 

[El Tigre]

Both engine oil,and transmission fluid eventually exceed temps in the coolant tanks. Transmissions are at risk from excessive heat. Whether it takes 5min. or 15 for fluid to reach operating temps scarcely matters. How many are even using the fluid that GM is now recommending in all of their transmissions is a far bigger factor in my opinion.

 

[BhutJolokia]

Both engine oil,and transmission fluid eventually exceed temps in the coolant tanks. Transmissions are at risk from excessive heat. Whether it takes 5min. or 15 for fluid to reach operating temps scarcely matters. How many are even using the fluid that GM is now recommending in all of their transmissions is a far bigger factor in my opinion.

What does GM recommend for these old 4L60Es? I believe mine was serviced with NAPA GM compatible synthetic not long before I bought it but I’m open to the idea something else is better next time around. I have never been able to find definitive source material saying a specific brand, just Dex III, I’ve always had great luck with Valvoline.


Thank you to everyone who has replied to my original post and continues this conversation, I’ve been a shade tree mechanic for a while but I always learn something from everyone and end up with information I didn’t know I needed or hearing questions I didn’t know I should have.

 

[thegawd]

Gm says dex VI transmission fluid is the fluid to be used wherever transmission fluid is called for, such as the transfer case as well. There was a bulletin about it waaaaay back stating it superceded dex 3. I have no source for that info but I have read it somewhere in the passed. Probably in the 4l60e technician manual. I'm sure its posted on here somewhere aswell. Lol.

Al

 

[HotWheelsBurban]

Supposed to be that all the more recent formulas of transmission fluid are supposed to be backwards compatible. DEXRON VI is synthetic though isn't it?
Having a similar issue with the F150. It's dipstick indicates that MERCON V is the proper fluid, and the owner's manual recommends not to mix it and regular MERCON. There's 2 different trannies used in 2001, and they use different fluids. At the parts store the other day, I was told that they all use MERCON V now. Confusing isn't it?

 

[df2x4]

Gm says dex VI transmission fluid is the fluid to be used wherever transmission fluid is called for, such as the transfer case as well. There was a bulletin about it waaaaay back stating it superceded dex 3. I have no source for that info but I have read it somewhere in the passed. Probably in the 4l60e technician manual. I'm sure its posted on here somewhere aswell. Lol.

Al

Automatic transmissions, yes. Manual transmissions and transfer cases that originally called for Dexron 3 are now supposed to use "Manual Transmission Fluid" part number 88861800. We had a discussion about this recently in this thread from post 50 on down.

https://www.gmt400.com/threads/time-to-get-serious-with-4l60e-4l65e-cooling.50138/page-5

 

[L31MaxExpress]

Gm says dex VI transmission fluid is the fluid to be used wherever transmission fluid is called for, such as the transfer case as well. There was a bulletin about it waaaaay back stating it superceded dex 3. I have no source for that info but I have read it somewhere in the passed. Probably in the 4l60e technician manual. I'm sure its posted on here somewhere aswell. Lol.

Al

I would NEVER use it in an older transmission. My 4L85E is getting Dex III as long as they make it. The seals will start to leak internally and it will cook. Info straight from a well known 4L80E builder that I have spoken with.

 

[Pinger]

I would NEVER use it in an older transmission. My 4L85E is getting Dex III as long as they make it. The seals will start to leak internally and it will cook. Info straight from a well known 4L80E builder that I have spoken with.

The drop in viscosity makes me very wary.
I intend using DEX III and an upgraded version that is no longer licenced by GM but because of that the manufacturer has the freedom to formulate to their desire and absolutely it will not be an inferior product to the GM sanctioned DEX III it supersedes.

 

[El Tigre]

There is no Dex III,and hasn't been since 2011 when GM removed all licenses/certifications. I can tell you that both my '98 C/K,and '96 Impala responded very favorably to being changed over to Dexron VI. Shifts are quick,and smooth.