What's the ideal temp range for trans oil?
- Thread starter McHaggis
- Start date
David Husek
Turbo Buick Performance
- Joined
- Mar 16, 2007
The best operating temp for a 200-4R is between 160 to 180 degrees. Temperature above these marks for a long period of time will shorten the life of the trans. Being too cold is a problem also as the trans cannot operate correctly when too cold and will cause clutches/band to slip when under power. Here is an instance of too cold. I drove my car in lock-up for an hour or so straight at zero degree outside temp. Engine temp was 155. Trans had large aux cooler after radiator. When I got off the highway and pulling away from a stop sign, I applied some mild power to the trans and slipped the second gear band. The fluid was so cold/thick the band could not apply. I continued driving in lock-up and the next time I stopped I checked the temp by physically touching the trans and there was no heat in the trans at all. No heat is generated when in lock-up. I am sure you can operate at 130 to 190 degrees without issue, but I recommend 160 operating temp. Any questions, give me a call.
Where you affected by the tornado or the earthquake .
Where you affected by the tornado or the earthquake .
Hi Dave. No issues here from either. The earthquake was about 350 miles away so I never felt it. I hope all is good with you?
I have run my trans for a couple of years now and have clocked up about 6000 miles without too many issues and none caused by heat.
As you said in your reply there isn't any heat to speak of generated when in lockup so my trans temp rarely climbs over 140 and sits for the most part at or under 120, as this is as low as my temp guage reads. I don't run the oil through the radiator but I guess I should be as Hensleyt does. Are the oil cooler bypass valves any good? They all seem to open at 180 so that seems to me to be opening about 20 degrees too late.
I have run my trans for a couple of years now and have clocked up about 6000 miles without too many issues and none caused by heat.
As you said in your reply there isn't any heat to speak of generated when in lockup so my trans temp rarely climbs over 140 and sits for the most part at or under 120, as this is as low as my temp guage reads. I don't run the oil through the radiator but I guess I should be as Hensleyt does. Are the oil cooler bypass valves any good? They all seem to open at 180 so that seems to me to be opening about 20 degrees too late.
I have found a bypass valve that opens at 160 degrees.... https://www.holley.com/products/plu...e/cooling_systems/oil_thermostat/parts/501ERL
Would this be a good option to get the temp up or would running the oil through the radiator after the cooler be enough?
My engine normally runs at 150 -160 on the freeway and 180 in the city.
Would this be a good option to get the temp up or would running the oil through the radiator after the cooler be enough?
My engine normally runs at 150 -160 on the freeway and 180 in the city.
I'd say as low as you can get it while cruising. I've never seen one go bad because it was too cool. The real problems come from inadequate cooling. The radiator/fan(s) have to have enough cooling capacity. The trans cooler is on the cold side of the radiator. When a car is drag raced the trans temps can hit 300*. If the car is hot lapped or required to run another round without adequate cool down it is advised to suck out the hot oil and replace with cold oil. When the trans gets hot it takes a lot of idling to get it back down and a hot day will make it much worse. 10 minutes of idling won't be enough to get it back down. If you were at 300* after the first round and it was 130* at the line and it's now 220* and you are about to make another hit it's not going to be a good day. You will probably cause damage and oil down the track.
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turbo nasty
Turbo Dojo / MNTR
- Joined
- Jul 19, 2001
Basic temp guideline
turbo nasty
Turbo Dojo / MNTR
- Joined
- Jul 19, 2001
IMO sump is best place. Line out isnt telling you what the trans is ingesting.
VtheGNMan
Well-Known Member
- Joined
- May 19, 2014
Chart is pretty cool and good info.
I'd be curious on the other side of these temps as in the low temps as its warming up. Until the oil gets to a certain temp wouldn't it be thicker and not flow as well etc?
That's the reason why I posted this. Mine sits at or below 120, 90% of the time and rarely goes over 140. I've never seen it over 160.
But since it works fine I guess I'll leave it be unless there is a negative to it running this cold.
turbo nasty
Turbo Dojo / MNTR
- Joined
- Jul 19, 2001
If your temp is in the sump what is the temp when brake boosting and then after a pass. Or back to back hits? It has to heat up if not something is not right.
NY Twin Turbo
All the good stuff.....Times 2.
- Joined
- Dec 10, 2014
On my 400......I have a Setrab cooler on a Spall fan up front for the standard trans cooling. I don't run the fluid through the radiator. If the temps goes up much above 180, I turn the fan on. But that's not enough sometimes. Especially on a hot day when I want to give it a hit or two on the highway...... it can get hot fast!
That's when I use plan B.
I have a Tilton auxiliary fluid pump (size and shape almost exactly like a alky pump). I mounted it under the car near the passenger frame rail along side the trans. Then I had B. Cotton weld two No.8AN bungs into opposite sides of the deep aluminum pan. I used an old stainless fuel filter element on the inside of the pan on the pick-up side. I pump the fluid out of the pan, to the back of the car (I have a fuel cell in the trunk so no fuel tank in the way) where I mounted a big-ass B&M cooler on another Spall fan.
All this is controlled by a single switch I can flip whenever I don't like the temps I see on the gauge. And then fused power comes directly from the battery. This way I can cool the trans down even when the car is not running.
I can cool down my fluid in a just minutes when ever I want. Or keep it from getting hot. It just plain works!
It may seem like overkill. But I bought the pump from a "sell-off unfinished project victim" and the rest of the stuff I had laying around from my old combination.
That's when I use plan B.
I have a Tilton auxiliary fluid pump (size and shape almost exactly like a alky pump). I mounted it under the car near the passenger frame rail along side the trans. Then I had B. Cotton weld two No.8AN bungs into opposite sides of the deep aluminum pan. I used an old stainless fuel filter element on the inside of the pan on the pick-up side. I pump the fluid out of the pan, to the back of the car (I have a fuel cell in the trunk so no fuel tank in the way) where I mounted a big-ass B&M cooler on another Spall fan.
All this is controlled by a single switch I can flip whenever I don't like the temps I see on the gauge. And then fused power comes directly from the battery. This way I can cool the trans down even when the car is not running.
I can cool down my fluid in a just minutes when ever I want. Or keep it from getting hot. It just plain works!
It may seem like overkill. But I bought the pump from a "sell-off unfinished project victim" and the rest of the stuff I had laying around from my old combination.
Buckshot G/N
Well-Known Member
- Joined
- Nov 2, 2011
I run a autometer Phantom Temp gauge , with the sensor tap into the pan, on a typical day here the south USA.At operating temp
it usually runs between 140 an 160 degrees ,even in the summer time the hottest it ever run was 180 degrees.
it usually runs between 140 an 160 degrees ,even in the summer time the hottest it ever run was 180 degrees.
Sender is in the sump. When it's not in LU is can get warm but I don't recall what temp it gets to on the track. I don't remember ever seeing it go over 170 and that was a hot day climbing a long steep hill in 2nd & 3rd, so it can warm up quickly.
My concern was with it running so cool, under 120, when in LU on the highway. But as I've said, I haven't ever had a known issue with it from running this cool.
David Husek
Turbo Buick Performance
- Joined
- Mar 16, 2007
Don't put full power to it when you get off the highway till the converter puts some heat back into the trans for longevity of the clutches and band. It will warm up extremely quick when not in lock-up. Your temps are fine, 120 will still thin the oil, wait for the gauge to go above 120 before spirited driving. Don't make any changes, just be conscious of the temp and you have nothing to worry about. My situation the oil was most likely below 40 degrees. Doubt you will ever have this issue as most do not drive in below zero degree weather.
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