What's Harder On Tranny

[Big Tool]

Towing in OD or just letting it ride in 3rd. I was just screwing around last night and dropped my tranny in 3rd gear on the intersate just to see what my rpms would be while towing a heavy load at interstate speeds. About 3k rpms, which was actually silky smooth. I ran it in 3rd for a few miles monitoring mpg, and also tranny temp and my tranny temp actually went down a couple degrees.

[bryanhunt]

Towing in OD or just letting it ride in 3rd. I was just screwing around last night and dropped my tranny in 3rd gear on the intersate just to see what my rpms would be while towing a heavy load at interstate speeds. About 3k rpms, which was actually silky smooth. I ran it in 3rd for a few miles monitoring mpg, and also tranny temp and my tranny temp actually went down a couple degrees.

 

It all depends on your vehicle and what you're towing. Tranny life is 100% related to fluid temperature. However if your truck doesn't have a tow/haul mode switch you want to tow in 3rd (look in the manual it'll tell you what gear, the vast majority of the time is 3rd).

 

Tow/haul mode is a different story though. In that mode the truck won't gear hunt like it would normally, so you can safely drive in OD (though unless you are almost perfectly flat without much drag) it'll likely be in 3rd. However the rule of thumb is always to read the manual that came with your truck.

 

 

(what I learned growing up was this simple formula: every 20 degree increase in tranny temp above 175 degrees F. cuts the life of the ATF in half... when your ATF is burned you can say goodbye to your clutch packs)

[Big Tool]

Towing in OD or just letting it ride in 3rd. I was just screwing around last night and dropped my tranny in 3rd gear on the intersate just to see what my rpms would be while towing a heavy load at interstate speeds. About 3k rpms, which was actually silky smooth. I ran it in 3rd for a few miles monitoring mpg, and also tranny temp and my tranny temp actually went down a couple degrees.

 

It all depends on your vehicle and what you're towing. Tranny life is 100% related to fluid temperature. However if your truck doesn't have a tow/haul mode switch you want to tow in 3rd (look in the manual it'll tell you what gear, the vast majority of the time is 3rd).

 

Tow/haul mode is a different story though. In that mode the truck won't gear hunt like it would normally, so you can safely drive in OD (though unless you are almost perfectly flat without much drag) it'll likely be in 3rd. However the rule of thumb is always to read the manual that came with your truck.

 

 

(what I learned growing up was this simple formula: every 20 degree increase in tranny temp above 175 degrees F. cuts the life of the ATF in half... when your ATF is burned you can say goodbye to your clutch packs)

 

 

 

ATF=Automatic Transmission Fluid I've noticed my tranny getting to 180 a couple times while towing, do i just need to keep an eye on my tranny fluid

[bryanhunt]

ATF=Automatic Transmission Fluid I've noticed my tranny getting to 180 a couple times while towing, do i just need to keep an eye on my tranny fluid

 

175 is like.... 100000 mile life... 195 is 50000 ... 215 is 25000... etc

 

 

I wouldn't go 100k on a single tranny flush anyway.

[Big Tool]

ATF=Automatic Transmission Fluid I've noticed my tranny getting to 180 a couple times while towing, do i just need to keep an eye on my tranny fluid

 

175 is like.... 100000 mile life... 195 is 50000 ... 215 is 25000... etc

 

 

I wouldn't go 100k on a single tranny flush anyway.

 

 

 

Thanks for clearing that up for me. I usually get it changed every 30,000 or so, i doubt i'll have any problems. My avalanche didn't have a digital readout so i can't rember what it ran on average, but i have noticed my new trucks tranny staying 170-180 which i thought to be alittle high. I have my front lower air dam removed and i hope it's not affecting anything. I may put it back on now it's getting summer heat and see if it affects temps.

[C & A s Dad]

If you can keep your temps running 175 to 180 in the summer you are doing great. My guess is as you get into summer heat and encounter some hills and or heavy traffic, you may see your temps rise over 200. Some do not worry about his but IMO this is too high. The warning light in GM trucks does not even come on to above 225 if I am correct.

 

I replaced my OE cooler with a 11" x 11" stacked plate designed cooler and to date just to keep my summer towing temps well below 200.

[pwall]

Towing my trailer (6000lbs) a few weeks ago, the tranny stayed around 71C (160F). This was in overdrive. Of course, I'm expecting this to go much higher come summer time.