Transmission Temp ?

chevyhutch · October 9, 2007

what temp does your Tranny Temp run in normal driving (not towing) ? I have the 4.8 and 3.42 gears. and mine today got up to 192 degrees (outside temp was 90),

I bought a tranny cooler to put on my truck,but my mechanic says i don't need it i'm just wasteing money. he said he would put it on but i would never know it was installed.

What say you guys ?

my ENGINE temp seems to go to high at idle ? my fans don't come on quick enough when at idle the heat hand goes way past 210degrees before fans come on. but idle with the a/c on the fans are running and it stays at 210. can you set it were the fans come on at 210 without the a/c on ? i don't know why they let it get so hot before the fans kicks on

Thanks, Rodney

iminaquagmire · October 9, 2007

I have the 5.3 and 3.42's. My tranny never gets above 160 though I do have a trans cooler. On a side note, mine actually seems to have gone down on average after installing the billet grille. I'm guessing even more airflow to the cooler.

It sounds to me like you're confusing the trans temp with the engine coolant temp. If my transmission was running at 210 degrees at idle I'd be a little concerned.

larryf · October 9, 2007

If you are talking about the trans fluid temp, I would add the cooler. Thats too hot for non towing temp and I get concerned when it gets above 200 when towing.

cmoore74 · October 9, 2007

Yup, unless you've added a gauge to read trany temp (scan gauge 2, aeroforce interceptor, or 3/4 ton gauge cluster) sounds like you might be looking at engine coolant temp.

If not, I have the same engine with the OEM cooler that comes with the trailering package. Not towing my tranny is down around 120-140 deg F (when about 80-90 deg outside). When I tow my boat it goes up to about 160-180 deg F.

Many will say always get a cooler, but IMO unless you're towing or hauling heavy loads you don't need a cooler especially since these new transmissions are now being filled with synthetic fluid.

If you are towing/hauling then I would definitely get one. There a number of good coolers out there. I have had good luck with B&M.

CenWaSS · October 9, 2007

Mines doesnt get much higher than 150F while towing. Under harder conditions, at the track/power breaking etc I might see 170F at the highest. I've also got a tranny cooler with 6.0L and 4.10 gears.

chevyhutch · October 10, 2007

I have the 5.3 and 3.42's. My tranny never gets above 160 though I do have a trans cooler. On a side note, mine actually seems to have gone down on average after installing the billet grille. I'm guessing even more airflow to the cooler.

It sounds to me like you're confusing the trans temp with the engine coolant temp. If my transmission was running at 210 degrees at idle I'd be a little concerned.

I just edited my post , hope it makes more sense now !

no i'm not confusing the two, sorry if my post sounded like it . but i had questions about both engine and tranny temps. mine has the trip thing in the cluster where it gives you the tranny temp. and i check it often, like i said earlier on a 90 degree day not towing or hauling anything my tranny temp went up to 192 degrees. is that normal ? seems high to me, what if i had been towing something what would it had gone to ? I don't tow any real heavy stuff just 5x8 trailer with a 600# ATV on it.

and the ENGINE temp at idle with no a/c on, it goes well past 210 degrees before the fans come on and cool it back down to 210 ? if you turn the a/c on the fans come on and the temp stays at 210 ?

i think the fans should come on just as soon as it hits the 210 mark whether or not the a/c is on.

MS3DALE · October 10, 2007

Rodney,I think you and I have talked about this before,When I towed my buddies Corvette from down your way (Hickory) to up here (Pittsburgh) I saw my tranny temp. go up to 196 degrees,I don't think it ever went over 200.

Now not towing anything I'm not sure,I've never really paid any attention to it,I was concerned with the temp. while I was towing but I don't worry about it when I'm not towing.

I tell you what though...I'm heading down your way tomorrow for the NASCAR race this weekend down at Charlotte,I'll check it out frequently while I'm driving and post what the temp. gets up to. (If I remember,My age is starting to affect my memory )

BTW...Add the cooler no matter what,Its cheap insurance,and it won't hurt to have it.

chevyhutch · October 10, 2007

Rodney,I think you and I have talked about this before,When I towed my buddies Corvette from down your way (Hickory) to up here (Pittsburgh) I saw my tranny temp. go up to 196 degrees,I don't think it ever went over 200.
Now not towing anything I'm not sure,I've never really paid any attention to it,I was concerned with the temp. while I was towing but I don't worry about it when I'm not towing.

I tell you what though...I'm heading down your way tomorrow for the NASCAR race this weekend down at Charlotte,I'll check it out frequently while I'm driving and post what the temp. gets up to. (If I remember,My age is starting to affect my memory )

BTW...Add the cooler no matter what,Its cheap insurance,and it won't hurt to have it.

yea i've got the cooler here at the house, just have'nt got it installed yet. i ordered from Modern Chevrolet they wanted $200 to install it i said no thanks. the garage that's going to install it for me said he has put many of them on and it would run me $50-60 bucks. now this wont void my warranity in anyway with me installing it instead of dealership ?

What about the engine temp going way past 210 when idleing with a/c off. why does it get so hot before the fans kick on ?

C & A s Dad · October 10, 2007

Rodney, put the cooler on.You want to keep the trans temp below 200 if possible and if you have a good cooler, you will have no problems. If you ordered it from a dealership, I am guessing it is an OE style cooler which is a stacked plate design. It will not restrict the fluid flow, will cool very efficiently and will certainly go far in extending the life of your trans.

As far as the engine temps. From what I have read, this seems to be the norm with trucks with E fans. Mine is an 02 and has a mech fan and a fan clutch. I have seen it just over 200 on a upper 90s day after it had been idleing for about 10 mins. As soon as I pulled off, it dropped back down to 196 or so. It just seems the e fans are set to come on at thse higher temps.

MS3DALE · October 18, 2007

OK,Sorry its so late but heres what my tranny temps. were on my trip this past weekend...

When we left Wednesday around 5 in the afternoon it was around 65 degrees outside,The tranny temp. ran between 131-159 degrees the whole trip down.

On the way back it was a little warmer outside,we left around 11 in the morning and it was around 75 degrees,the tranny ran a little warmer also,it ran between 141-169 degrees,The only time I noticed the higher temps. was when we were going up over Fancy Gap on I-77.

This was running 75-80 MPH and turning 2300-2500 RPM's with my 6-liter w/3.73 gears.Also I was not using the A/C.

Zembonez · October 20, 2007

OK,Sorry its so late but heres what my tranny temps. were on my trip this past weekend...
When we left Wednesday around 5 in the afternoon it was around 65 degrees outside,The tranny temp. ran between 131-159 degrees the whole trip down.

On the way back it was a little warmer outside,we left around 11 in the morning and it was around 75 degrees,the tranny ran a little warmer also,it ran between 141-169 degrees,The only time I noticed the higher temps. was when we were going up over Fancy Gap on I-77.

This was running 75-80 MPH and turning 2300-2500 RPM's with my 6-liter w/3.73 gears.Also I was not using the A/C.

Another Trans Temp Update: Towing.

Took my boat on a trip to the lake this morning to do a little fishing (that and my wife likes to have lunch on the lake). It's about a 45 minute drive up some pretty good hills. Paid very close attention to the trans temp. On level ground hovered near 180 and I saw a high of 203 when I crested one 3/4 mile long hill on the way back. It dropped back in the upper 190s for the rest of the hilly terrain and then back down around 180 the rest of the way. I have no idea what normal is but I figured the more we post about it the more we can see what is about average. Another note. It seems like my trans temps run a little higher when I use tow/haul mode. Not sure why that might be.

5.3 / AT / 3.42 / pulling about 2400 lbs plus some gear.

davidhughrose · October 20, 2007

The new Dex VI apparently is superior to all previous fluids, and I'm sure it will help transmissions hold up better. Here's some broad, general temp info: http://www.txchange.com/heatchrt.htm

When in doubt, change the fluid. I need to run my wife and horse trailer into Vegas in about a month. I'll definitely change it after the trip.

chevinator · October 20, 2007

I check mine often, I like messing with the buttons and in south florida weather around 85-90 degrees it runs around 153 degrees thats not towing.I have the 5.3 with 3.42 and the transmission cooler.

nccrew · October 21, 2007

Central Florida - - around town - Trans Cooler (tow package) and 4.8 Auto Crew Cab with 3.73 = 180 degrees on average (moves up and down but thats about average during the day at 90 degrees outside) Starts out lower and stays there in the morning but as the heat rises, so goes the temp..

This is off of the Scan Gauge II.

I check mine often, I like messing with the buttons and in south florida weather around 85-90 degrees it runs around 153 degrees thats not towing.I have the 5.3 with 3.42 and the transmission cooler.

Max Diyer · October 21, 2007

If you want an automatic to last, there's 4 things you have to do.

1. Keep the ATF temp. in the tranny below 175 degrees, all the time.

2. Change the ATF and filter every 30k miles or less.

3. Don't abuse the tranny.

4. Keep the fluid level on the high mark.

I've had automatics last over 200,000 using these 4 rules. The proper procedure for changing ATF and the filter is important also. Here is a link to doing this the right way. Although it is on the Amsoil site, I am not promoting or do I use Amsoil. This information is the correct procedure for DIY ATF and filter changing.

Changing ATF & filter