Chrysler 41TE (A-604) Piston Housing Now Included in TransTec Kits

TransTec rebuild kits for the Chrysler 41TE (A-604) now contain the low/ reverse piston housing. This housing is stamped steel and is susceptible to distortion, especially around the screw holes. Therefore, the housing should always be replaced during a rebuild. In fact, ATRA recommends using a new housing in their recent technical bulletin #231.
The piston housing is fastened to the back of the case with three screws. When rebuilding, it is very important to tighten these screws to factory specs - 40 inch pounds. Improper torque of the screws may result in a leak. A leak will cause a loss of low/reverse clutch pressure, resulting in delayed forward and reverse engagements, harsh or slide-bang downshifts to first, and defaults to “limp in” mode when hot.
There is a gasket between the piston housing and the case, which seals the apply oil route for the low/reverse clutch. We have received reports of leaks due to failure of this gasket. The theory is that low/reverse clutch pressure forces the low/reverse piston housing against the case, compressing the gasket. This leaves a space between the piston housing and gasket where low/reverse feed oil can escape.
Although TransTec has already upgraded this gasket to a higher density material, we were not convinced that the gasket itself was the problem. In all the calls we have taken from rebuilders, we found the suspect gaskets to be only .001" thinner than a new gasket. Again improper torque of the housing screws and distorted housings may be a large part of the problem. So in order to eliminate all possible causes of failure, we are including a new piston housing in all TransTec gasket & seal kits and overhaul kits. The TransTec part number for this housing is #81638 (OEM #4431648). All TransTec kits with a date code of H94 and later will include the housing.

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