It is important that JASPER has a clear definition and policy that reflects the best interest of our customers and our company.  Past failure to address this issue has allowed misunderstandings within our company and among our customers.

Cooler free flow can range from one and one-half quarts to over four quarts in 20 seconds.  It all depends on the transmission.  We have established the average acceptable flow as two quarts in 20 seconds.  However, we also know that this is not true in all situations.  For example, the Dodge 47RE transmission requires up to four quarts in 20 seconds.

Replacing the vehicle’s system with an external cooler isn’t always the answer.  Consider the fact that the original manufacturer’s system uses the engine’s radiator to transfer the heat from the transmission’s fluid to the vehicle’s cooling system.  Under all conditions, this is consistent, since it is thermostatically controlled.  An external cooler depends on its ability to transfer the fluid’s heat to air, which is a less-effective method.  It is not monitored by a thermostat and depends on constant air flow to be effective.  There are two situations where they could cause a transmission failure.  One is where the air flow over the cooler is interrupted (snow plows, low-speed towing, stopped in traffic, etc.)  A second problem arises in extremely cold conditions where the transmission fluid is unable to warm-up.  In fact, under extremely cold conditions, it could contribute to the jelling of the fluid.

Flushing the system is no longer effective.  The newer-style coolers have complex internal grids used to enhance heat transferal.  These systems collect debris and are impossible to fully flush. Some systems have thermostats that open at 190 degrees.  The bypass on these systems causes a misleading appearance that the cooler itself is being flushed.

Comparing cooler flow as it exits the transmission to the flow after it passes through the cooler is not always effective.  Some Chrysler 41TE and 46RE coolers, that have contamination, could pass a flow test at normal operating temperature.  However, under load or hot conditions, the cooler will restrict the fluid flow to dangerous levels.

The point is, there is no single answer that fits all circumstances.  So, the next time you purchase a JASPER transmission go ahead and ask about adding a new Spectra radiator, cooler kit or flusher rental to your order.  Listed below are three blanket statements that are considered JASPER’s position.  They are listed in order of preference:

1. REPLACE WITH A NEW SYSTEM (RADIATOR).  Check flow to assure lines and check valves are OK.

2. REPLACE WITH AN EXTERNAL.  Keep in mind the above information and flow test.

3. FLUSH THE ORIGINAL SYSTEM.  A heated, hydraulic shock system is the best.  Flush in a can is not acceptable. Always flow test at operating temperature.

Check our blog next Friday for the answer and another Friddle.

Last Week’s Friddle: Besides Pontiac, what other automobile manufacturer produces a GTO?

Last Week’s Friddle Answer: Ferrari