MWSC FAQs: Clutch and Driveline

Can I build my own clutch through you guys?
Yes, we make it easy for you. Come up with a custom 6 digit part number by selecting the components you desire in your clutch. Simply follow these steps:

1. The first number will always be 8
2. For the second number, put 1 for a complete clutch without a 6 pin driver, and 2 for a complete clutch with a 6 pin driver
3. In the third number you’ll specify your desired disc: 1 for Kevlar Disc, 2 for 3 puck, 3 for 4 puck, and 4 for 5 puck
4. In the fourth number you’ll specify the release arm of your choice: 1 for narrow frame, 2 for wide frame, and 3 for 82-Series
5. For the fifth number, you’ll choose a spring: 1 for our red spring (800#), and 2 for our yellow spring (1150#).
6. For the sixth and final number, you’ll specify a driveshaft: 1 for narrow, 2 for narrow with a “coupler, 3 for wide, 4 for wide with a 3” coupler, and 5 for the 24” shaft for an 82-Series with no rear hole.

For example: To build a Complete clutch with a driver with a 4 puck metallic disc on a narrow frame with a yellow spring and our 3” coupler, your part number would be: # 823122

I’m new to pulling and need to update my clutch, what should I know?
If you’re entering a stock class, you may only need a new disc (our MWSC Kevlar Disc # 51155) and possibly a heavier spring for your existing clutch. The stock spring is a 300# spring, while the heavy duty spring (red in color) is an 800# spring (See our Beginner Clutch Package on page 14 in our 2019 catalog).

Why is it recommended to replace my stock pressure plates?
Although your stock pressure plates might not need to be replaced, they’re made of a thin material that tends to warp when used in pulling. Check the stock plates to make sure they’re completely flat; if they’re not they can be trued or replaced with our MWSC Pressure Plates (page 14 in our 2019 catalog), which are made from billet metal making them less likely to warp.

How far does the spring need to be compressed?
Our MWSC red and yellow springs are each 6” long, they need to be compressed to 4-½”.

Why is the Heavy Duty Release Arm necessary?
This part will make it easier to press down on the clutch pedal when using one of our heavier springs. We have three styles available: the narrow, wide, and 82 Series, all of which are longer and stronger than the stock arms (page 14 in our 2019 catalog).

Is it necessary to use the Teaser Spring?
Our Teaser Spring makes for a smoother engagement and allows you to feel when the clutch is engaging. We install one in every clutch assembled (page 13 in our 2019 catalog).

How do I know if my clutch is “running true”?
When the clutch is installed and the engine is turned OFF, measure the distance between the disc and the #3 or #6 lug driver in five or six spots - the measurements should be the same. If they’re not the same, shims will be needed on one side of the motor until measurements are all equal.

Which clutch should be used for a pro stock tractor?
You’ll need the Metallic Disc with four or five pucks on each side (page 14 in our 2019 catalog); along with this you will need our 1150# spring (yellow in color). This also requires replacing the stock drive shaft. (Note: If you use the four or five puck disc mentioned above, you will also need to replace the clutch driver to our MWSC Six Lug Aluminum Clutch Driver and replace the pressure plates.)

Which driveshaft works with an 82 Series tractor?
The 82 Series is a wide frame, but because these were made with a rubber boot coupler, the length of the driveshafts all vary. We make a driveshaft 24” long (page 13 in our 2019 catalog); when placing an order for one of our driveshafts you must specify which disc you plan on using: Metallic or Kevlar (page 14 in our 2019 catalog).
Although the front two holes in our MWSC shaft come pre-drilled, the rear hole will need to be drilled after determining the correct length. If you have our MWSC 3” Coupler (page 13 in our 2019 catalog) it may be used as a drill guide. Be sure to use coolant when drilling and keep in mind each hole is a weak spot in the driveshaft, so “measure twice to cut once”.
Standard length for a narrow frame tractor is 18-¼” and wide frame is 19-¼”.
The spring is held in place by a Split Collar (page 13 in our 2019 catalog); one split collar is used behind our 800# red spring, whereas two split collars are used behind our 1150# yellow spring.

Why use a Center Support Bearing # 52123?
A Center Support Bearing # 52123 (page 13 in our 2019 catalog), or pillow block bearing, is necessary in tractors running at or above 4000 RPM. When the clutch turns at a higher RPM, the driveshaft is also moving in a small circular motion; the Center Support Bearing # 52123 helps eliminate some of this circular motion. (It also helps with some misalignment issues.)

What are the differences between the Regular Metallic Disc # 52124, the Heavy Duty Metallic Disc # 52125, and the Super Heavy Duty Metallic Disc # 52126?
The Regular Metallic Disc # 52124 has 3 pucks on each side and it measures the same as the stock pieces.
The Heavy Duty Metallic Disc # 52125 has 4 pucks on each side and measures 6-½”.The pressure plates and six finger driver also have a larger diameter.
The Super Heavy Duty Metallic Disc # 52126 has 5 pucks on each side and measures 7”. The pressure plates and six finger driver also have a larger diameter.
There is a chart for HP and disc size on page 13 in our 2019 catalog.