Stephen P.
The F-350 Diesel engine oil, transmission fluid, and water temperature are all tied together, one goes up the other 2 follow. A diesel engine requires heat to run and work properly, if the engine is cold you need glow plugs to be able to generate heat to ignite the diesel since there is no spark plug. But that temperature must be controlled, so the fluid doesn’t fail due to extreme heat. That is were SPE Motorsport helps control the heat thru 4 different products, 1. Larger oil pan, 2. Larger oil cooler, 3. Larger transmission pan and new to their lineup is a 4. Larger transmission cooler for the 6R140 2017 thru 2019 years Super Duty series diesel trucks, the transmission cooler is Model # SPE-S100359.
Had an uninstalled SPE auto transmission pan from August 2024 and new SPE transmission cooler for truck to be installed on July16th when the fluid and filter were normally replaced due to mileage. It's a 2019 F-350 LWB SRW with only 58,000 miles. It's not a town car, 90% are freeway miles. 3 long road trips in 2025, those trips added 15,000 miles to truck. Twice to Pittsburgh and once to Statesville NC all in 2025
The bigger transmission pan and cooler and 17.4 quarter of new ATF fluid has made a difference. There is a total temperature drop between engine oil and transmission fluid temperature; the transmission is cooler than engine oil temp. Until you sit at the traffic light for a while but once the engine speed and road speed increase the temperature difference reappear.
Have increased the size of oil cooler and oil pan to lower engine oil temperature. The bigger oil pan holds 16 quarts of oil which helps lower the oil temp. I also upgraded and utilized the redesigned oil filter housing that not only utilizes CAT oil filter model # 324-2598 (Short filter), filtration but also adds to the flow/increases oil flow which also helps reduce engine oil temperature. The SPE oil pan increases the overall oil capacity to 16 quarts, which is an additional 3 quarts over stock.
The new SPE transmission pan holds an extra 8 quarts of ATF above normal/factory if totally dry it's normally 16 to 18 quarts. But normally a pan drop and filter change requires 8 to 12 quarts because fluid is trapped in other areas of the transmission system. The engine oil system most of the oil drains back into the pan not the case with the transmission. That's why it's important to service the transmission filter and AFT on a regular basis and replacing the fluid and filter on regular basis every 40,000 to 50,000 miles.
Before the July 16th upgrade on June 22 I drove up Sunset Point pulling a 5,500 lb trailer/RZR the water temp was 233, Oil temp 250 F, Transmission temp was 230. The last 2 temperatures are at the upper limits for the oil and transmission fluid. The Interstate 17 grade at Sunset Point (between Black Canyon City and Cordes Junction) reaches a maximum of 6%. This steep, continuous climb spans an 8-mile stretch and overcomes a 1,500+ foot elevation change, bringing the Sunset Point Rest Area to an elevation of 3,380 feet.
I was driving at 60 to 70 mph in 5th gear which is still in overdrive. It has a 6 speed transmission and 4th gear is 1 to 1 input to output.
Once the grade was over the temperature dropped dramatically. It was over 100 in Phoenix that day we drove up the hill.
I also have a 16,000 lbs trailer to tow but in the July 17th after new transmission upgrade were done I monitored both engine oil temperature and oil temperature it was not heavily load test, just in town driving to give it a local test. The true test will be in August a road trip Phoenix to Pittsburgh round trip about 4,500 miles, it will be a better test. I’m expecting all fluids to have reduced temperatures, because they are tied together even tho there is 2 different radiators systems. But if you cool down 2 of the 3 fluids it will effect the engine water temperature of the primary and largest radiator. It’s harder to lower engine oil and transmission fluid temperatures than the radiator anti-freeze.
lance c.
Pretty straight forward install. I did the oil cooler hoses at the same time because I was there. There is a noticeable difference when hauling equipment in this 100 degree heat down here. Would have given it 5 stars but it doesn’t come with new gaskets. I had to go hunt them down. Just be aware of that.
