O.E.M. = “Original Equipment Manufacturer”

In this video we looked at a GM B21 JSFM torque converter, which you find in a Pontiac Bonneville containing a 4T65 transmission.

The design of the OEM piston is not strong enough to withstand repeated lockup, which causes the outer diameter of the piston body to bow down. This destroys the friction material as well as the torque converter.

How do we fix this problem?

We place a bridge weld on the back side of the piston body, tying the spring casing and the piston body together. This provides extra support during the repeated lockup and keeps the outer diameter from bowing. This process is performed on 100% of this style piston to make sure each parts meets the highest quality standard.

These are just some of the ways DACCO is making OEM converters better.

Filming and Editing provided by Michael’s Video Production