HOW TO | CAConversions | Custom Automatic Conversions

How To Determine the Right Torque Converter

Once you determine that an Allison transmission is the best option, choosing the right torque converter is the next step:

1) What horse power is your Cummins running and what is your ultimate goal.

2) What is your total maximum weight while towing.

A) If you are under 450 horse power and tow only light loads a standard heavy duty (HD) Allison converter will be fine
B) If you are at about 450 to 550 horse power and you tow light loads a custom built “KC” HD single clutch torque converter will be sufficient.
C) Over 600 horse power triple clutch is always recommended.
D) With higher horse power and towing heavy loads, pulling or sledding a custom built HD triple clutch may be the best way to go

The stock GM converter that will come in a used Allison 1000 PK should ALWAYS be replaced. These converters are built with weak clutches and bearings and not uncommon, when used behind a Cummins the studs will tear out due to the low end torque demand. The converter can be used for a core towards the proper torque converter.

How To Get Started Determining the Right Allison for YOU

Thinking about putting an Allison behind your Cummins motor? There are a few simple steps to take in order to determine the correct Allison to choose:

1) What diameter tires are you running or do you want to run; go to the Allison RPM calculator page and enter tire size, ie: 235/85/16 or 265/75/17 and your tire diameter will be calculated.

2) Determine your rear end gears, ie: 3.73 or 4.10’s, if you do not know and nothing has been altered from the factory original; you can always call your dealership’s parts department give them the last eight numbers of the VIN and they can give you the correct information.

3) Enter that information on the left hand column and look at the chart to determine where you fall in the green range.

This will give you the place to start.