What I usually do is take...
What I usually do is take the rearend oil and pour it into a clear container and let it sit for a while so that we can inspect it.
First fill the rearend to the manufacturer's recommended level (usually marked), then spin the rearend to pump oil into the cooler to fill it. This can be done by jacking the rear of the car up, starting it, and putting it in gear. Finally, replace the oil in the rear that was pumped into the cooler.
An external pump will cost you somewhere between $250-300-that's pretty inexpensive when you consider replacing the entire $1,800 rearend.
The other type of pump is an internal pump, designed mostly for you guys and gals running a 9-inch rearend. External pumps can be a little bit of a headache when you're installing a new rear gear. However, the internal pump has everything contained inside. The downside is that every rear gear has to have an internal pump.
This is one form of an external...
This is one form of an external oil pump. This setup is available through Tiger Rear Ends. It attaches to the back of the gear cover and pumps oil through a cooling reservoir and then back into the rearend.
For our project USAR Pro Cup car we run a 9-inch rearend and fall into the category of running an internal pump. C&R Racing supplies us with the gears at each race through its rental program which works out great for low-budget teams like us who can't go and test before each race to determine the right gear. Plus, each of these rental gears comes with an internal pump, making changing the gears extremely easy. All we have to do is undo the hose and pull the rear gear out and put the new one in and reattach the hose.
To Treat Or Not To Treat
Metal treatments are another excellent way to reduce the wear and tear on your rearend-and there are a number of them out there. The Feb. '09 issue of Circle Track has a story that showed how some teams used only one quart of oil in their rearends thanks to Tiger's new RF-85 treated Quick Change Rearend. We found that the RF-85 Metal Treatment actually lowered the operating temperature of the rearend. The team in the story ran as little as one quart of oil and it gained a small horsepower advantage. Less rearend lubricant translates into more horsepower if the gears and internal components can stand up to the heat and stress. Tiger's RF-85 rear proved that to be the case and even saved the team some money on buying rearend lubricant.
This is the other version...
This is the other version of an external oil pump. It attaches to the rearend yoke and spins. This setup can be a pain for the 9-inch rearends, but might be a decent setup for a quick-change rearend.
Metal treatments like RF-85 are perfect for a Dirt Late Model or an Asphalt Late Model team running a quick-change rearend. You can gain the benefits of a metal treatment by just treating the main gear. Conversely, the design of a 9-inch would require you to have every gear treated in order to realize the benefits which would in turn increase the cost.
Install A Temperature Gauge
I once leaned in to a Super Late Model to talk to a friend of mine and I noticed that he had two temperature gauges on his dash. After the practice session I asked him about it and sure enough one of them was the temperature of the rearend. I thought this was sheer genius. I'd never even thought about wiring a gauge to the rearend. Most of us take for granted that the rearend is running at the correct temperature. But if it gets too hot, disaster could be lurking around the next turn. A good temperature gauge will allow you to spot trouble well before it becomes expensive.
Installing one is pretty easy as well. The rear oil temperature sending unit should be installed inline with the return line from the oil cooler to the rearend so it can monitor the "cooled" oil temperature. This is similiar to oil temperature gauges installed in the motors. Just be careful to keep its wires free of the driveshaft or other obstructions that could cause damage.
Conclusion These steps may seem elementary, but it's amazing how we get concerned with the setup while forgeting even basic maintenance on the rearend. This season, take a closer look at the rearend, it may just help you get to Victory Lane.
Having a metal treatment done...
Having a metal treatment done to your rearend will help keep the heat down in the rearend.
By keeping a close eye on...
By keeping a close eye on the rearend and performing basic maintenance throughout the year, you can avoid problems that will lead to heat buildup inside of it.
Here you can see a rearend...
Here you can see a rearend cooler mounted to a quick-change rearend. Notice how the cooler is higher than the rearend.