It’s very easy to not fully engage the torque converter into the front pump and input shaft splines on many automatic transmissions. The converter connects to both of these components and if the final connection is not made, the converter will be left too far forward on the input shaft. This will force the converter against the flexplate and serious damage may occur to both the engine and transmission if the installer tries to force this arrangement.
The standard procedure is to measure the amount of setback of the torque converter mounting flange to the bellhousing flange. A common number for most transmissions is slightly more than one inch but we’ve included a more accurate list in the accompanying chart for the more popular transmission applications.
Placing the converter on the input sounds easy, but we’ve occasionally struggled with this in the past. One TH400 fought us for almost 30 minutes and needed some minor persuasion with a soft mallet before it was finally completely seated.
If the converter is not fully engaged on the input and then forced onto the flexplate, this will press the engine crankshaft forward and very quickly destroy the crankshaft thrust bearing and also damage the transmission as well. This will require serious repairs to both engine and transmission, so it’s imperative that this converter setback from the bellhousing flange be verified before installing the trans to the engine.
This chart lists the clearance from the converter mounting pads to the bellhousing flange measured with the transmission free from the engine unless otherwise specified.
|Chrysler Torqueflite 727||
1 ¼” from Bell Housing to Ring Gear
|Chrysler Torqueflite 727||1 9/32” from Bell Housing to Pads|
|GM TH350||1 1/8″ from Bell Housing to Pads|
|GM TH700R4/4L60E/2004R||1 1/8″ from Bell Housing to Pads|
1-3/16″ from Bell Housing to Pads
|GM Powerglide||1-1/8″ from Bell Housing to Pads|
|GM 4L80E||1-1/64″ from Bell Housing to Pads|
|GM 4L60ELS1||1-1/64″ from Bell Housing to Pads|
|Ford C-6/C-4||1-1/8″ from Bell Housing to Pads|
|Ford Case Filled C-4||27/32” from Bell Housing to Pads|
1-1/32″ from Bell Housing to Pads
|Ford AOD||1″ from Bell Housing to Pads|
|Ford 5R55S||1” from Bell Housing to Motor Plate|
|Ford E4OD/4R100/5R110||29/32” from Bell Housing to Pads|