For this installment of R&R Tech I would like to take some time to discuss how engine performance can affect the transmission operation. We have all heard it before; the engine must be running properly in order for the transmission to function correctly. What does “properly” mean in this scenario? We all use different terms when we tell the customer, “You need to get the engine running properly” or good, correct, better, whatever terms we use; in our minds it all means the same thing.
The transmission rebuilder accused the R&R man of breaking the pump during the installation process. The R&R man was certain that he had done his job correctly and that the rebuilder must have done something wrong during the rebuild. To help pinpoint the problem, a pressure gauge was installed into the line-pressure port. To everyone’s surprise, the line pressure was normal. This meant that not only was the pump not broken but also the PR valve was not stuck open. This also meant that the transmission would have to be removed from the vehicle and at least partially disassembled.