A common failure of listed Ford transmissions is cracking of the forward drum at the snap ring groove. The manufacturing process of the OE snap ring groove creates high-stress points around the circumference of the drum. The drum is active in 1st, 2nd and 3rd gear ranges and suffers the most abuse on a forced 4-3 kick down when it reapplies at higher pressure.
The concurrent pressure from the forward clutch piston combined with the high stress at the snap ring groove causes the upper portion of the drum to split and separate at the groove. Depending on severity of crack, this can result in no forward engagement or slipping in 1st, 2nd and 3rd gear. The forged, one-piece construction of the Sonnax Smart-Tech forward clutch drum 76654-01K eliminates weakness at these stress points.
I have used this in a 600whp supercharged Mercury Marauder along with other Sonnax parts, and man did the customer love what we did. You guys are the masterminds of this industry.J. Johnson
Crystal Lake Transmissions
March 07, 2014
Topics: Rebuilding Tips Diagnostics And Theory Transmission Report Newsletters Transmission Toyota/Lexus Chrysler A340E Transmission A340F Transmission 48RE Transmission 46RH Transmission 47RH Transmission 46RE Transmission 47RE TransmissionRead Now
May 26, 2015
Topics: Diagnostics And Theory Transmission Report Newsletters Valve Body Reaming Transmission Ford 5R110W Transmission 6R140 TransmissionRead Now
March 09, 2016
Topics: Transmission Report Newsletters Transmission Toyota/Lexus U341F Transmission U341E TransmissionRead Now
May 22, 2015
Topics: Diagnostics And Theory Transmission Ford 4R75W Transmission 4R70W Transmission 4R70E Transmission 4R75E TransmissionWatch Now
September 30, 2005
Topics: Diagnostics And Theory TransmissionRead Now