Guidelines produce quality rebuilds

Easy guidelines produce quality Ford CD4E rebuilds

OEM CD4E Turbine Hub

OEM CD4E Turbine Hub
Modified CD4E Turbine hub with thrust washer.

Modified CD4E Turbine hub with thrust washer.

Ford currently uses three different converters for the popular CD4E transmission. They are: Dacco part number F67 for the smaller 2.0L engine, F69 for the larger 2.5L engine; and the F70 found in the largest 3.0L engine. These parts are easy to figure out since the size of the engine relates to the size of the part number. Another way to remember which part is required is the code located directly on the crank shaft pilot, which also corresponds to the engine size. Code A represents the smallest, Code C for the middle-sized engine and Code H for the larger 3.0L.

These converters have become quite popular since 1994 and continue to plague some rebuilders with performance issues. Impeller bushing concentricity and alignment must be carefully monitored during assembly. Sizing of the impeller bushing needs to be maintained between 1.759 and 1.765 inches for proper clearance. Excessive clearance, here, can cause erratic converter clutch operation. Make sure your customers carefully check the pump stator surface for any scoring or wear, which can cause premature bushing failure.

Proper T.I.R. is also a must in order to prevent f ront seal leakage. Improper hub runout in excess of .007 is beyond its performance limit. Be sure to use a newer collate adapter to ensure proper alignment during the welding process.

After the converter is placed in the welding fixture, be sure to use an indicator to check both impeller and hub for parallel and perpendicular alignment. This is an area where many rebuilders spend additional time to assure a quality rebuild is the end result.

The CD4E converter responds well to the use of many clutch liners. If you choose to use a Kevlar-type clutch liner, be sure to bond to the piston and polish the front cover mating surface to a smooth 15RMS or better finish. This converter does not like an aggressive clutch engagement and can result in damper failure.

The F67 converter has a noted history of metal-to-metal contact between the impeller hub and front co ver. This problem has been solved through Ford by installing the same aluminum thrust washer as used in the General Motors TH440-type converter. Yes, this is the same part. You are able to remachine a pocket on the end of the impeller hub to accept this small bumper-type washer and eliminate chances of a comeback due to metal contact and transfer (see photo). Proper clearance must be checked after the modification to ensure proper clutch clearance.

Finally, converter end play must be held to a low limit of .022 inches for proper performance and bearing life.

 Found in issue August 2005