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Installing a deep transmission pan on a 4R70W is worth its weight in gold
The world is full of minor inconveniences, and changing transmission fluid is one of them. The job doesn’t need to be complicated, but on some cars it is. When we find the accountant who decided that our 4R70W transmission didn’t need a drain plug, we’re going to intentionally put him on duty at a quick-change oil and lube facility. What were they thinking?
There is no good, easy or clean way to drain the fluid, and usually we end up wearing at least a quart of the slippery red stuff, so dress appropriately.
Installing a drain plug in our existing transmission pan would be easy enough, but we had another plan in mind. Since the early 4R70Ws are notoriously weak, we decided to upgrade this Thunderbird with a B&M deep transmission pan. This new pan is made from cast aluminum with fins to aid in cooling, and it holds three additional quarts of fluid. That means our transmission fluid will run cooler, and cooler fluid means the transmission will lead a longer life. And it even has a drain plug.
Although the pan’s instructions only specifically mention application on an F-150, we had no problems installing the pan on our car. Thus, it should fit any car equipped with a 4R70W, with one caveat: ground clearance. This car is lowered, and while the pan easily survived our 2,800-mile (we went sightseeing and stopped here and there) road trip east, your car may be slammed lower than ours. Our transmission temp gauge tells us that the biggest benefit so far is that ambient temperature changes don’t affect our fluid as much as before, and the fluid runs a few degrees cooler. During autocrossing, we’ve seen the temp gauge pegged at 250, so we were happy for the upgrade, and we expect that it will help prolong the life of the 4R70W and improve its performance. If you autocross, or even live in a consistently hot climate, this upgrade should almost be considered mandatory.
Installation is identical to that of a stock pan, so we figure you don’t need us to tell you how to install it. Instead, we’ll focus on the difference between the two pans.
