4T40E PR Valve Repair

1995 to 2010 General Motors vehicles equipped with the 4T40E and 4T45E automatic transmissions are prone to wearing out the line pressure regulator (PR) valve bore.

The purpose of the PR valve is to regulate the transmission line pressure. If the PR bore wear is severe enough at the balance end of the valve, it can result in erratic or high line pressure. On the other hand, in those cases where the wear is most prevalent at the spring end of the valve, the leak in that area would cause erratic or low line pressure. Consequently, the symptoms will vary ranging from harsh shifts, soft shifts, burnt frictions, overheating, to converter clutch failure.

Features and benefits:

This TransGo oversized PR valve is a USA-made precision ground hardened steel valve that restores the hydraulic integrity of the circuit. The kit also includes a new spring seat and a new spring that is designed to provide the correct line pressure with the larger diameter valve. Lastly, the kit comes with a replacement pump slide spring since the original spring often breaks.

Since this is an oversized valve, the PR bore will need to be reamed.

• If you need the reamer and guide, order TransGo part # 4T40E-PRT. This tool kit also includes enough parts to fix three transmissions.
• On the other hand, if you already have the tools, then order the refill kit TransGo part # 4T40E-PR5. This refill kit comes with enough parts to fix five transmissions.

Corrects/Prevents/Reduces:

• Lock-up complaints
• Soft shifts
• Harsh engagements or shifts
• Burned forward or reverse frictions
• Codes P0741, P0742, P1887
• Overheating or burned fluid