DP Clutch Plates for Evos

This story appears in issue #369, which has yet to even hit subscribers’ mailboxes. Consider this a super-private reveal of the kind of tech you’ll find in every issue of American Iron Magazine. Subscribe here and purchase back issues here

How to replace the worn-out steel and friction plates in your Big Twin’s clutch with new DP parts

by Chris Maida

So, how do you know when it’s time to replace your clutch’s friction and/or steel plates? You’ll know you need a new set of friction plates if you squeeze the clutch lever and try to click the transmission into first gear and you hear an unpleasant crunch! You’ll also get that crunch if your bike’s clutch and/or clutch cable is not properly adjusted. Another indicator of bad clutch plates is that the bike will want to creep forward when you’re stopped even though the clutch lever is fully pulled in. This problem can also be caused by an improperly adjusted clutch and/or cable. However, the most frequent indicator of a worn-out clutch is when the clutch slips when you open up the throttle. You can tell the clutch is slipping if the engine revs up but the bike doesn’t really move much faster. And though, like the previous two unwanted issues, this problem can also be caused by a clutch that needs to be adjusted, the cause is usually worn-out friction plates. In fact, many times a slipping clutch will also heat up and distort the clutch’s steel plates. An easy visual indicator of this is a bluish color on the steel plates, which means the steel plates also need to be replaced.

If you’ve tried adjusting your clutch to no avail, no worries! The folks at DP Brakes, the company that sells excellent brake pads for all models of Harley-Davidsons, also make excellent friction and steel clutch plates for all Sportster and Big Twin models. DP friction plates do not need to be soaked in primary oil before installation, like most other brands of friction plates. DP’s friction plates are made of high-heat materials to eliminate clutch fade and give you smooth power delivery. They’re able to stand up to heavy clutch use, like long periods of stop-and-go traffic without a problem. Jerry “Motorman” Palladino, the Ride-Like-A-Pro guy, states in a YouTube video how he loves DP clutch plates since they hold up to his long practice sessions of using the clutch’s friction zone while making super tight turns. As for DP’s steel plates, they’re precision made of quality, heat-treated steel for smooth progressive clutch action. And yes, a set of DP friction and steel plates can handle more engine power than the stock plates because of these improvements.

In this article, we’re going to show you how to replace the worn-out friction and steel plates on your 1990-97 Evo Big Twin with a new set of DP friction and steel plates. We will also tell you how to properly adjust the clutch after it’s installed. In fact, if you’re not sure if your clutch problems are due to a bad adjustment or worn-out plates, readjust your clutch and its cable as explained in the sidebar and then test ride your bike to be sure.

Tool Tip

To do this installation, you’re going to need a special tool called a spring compressor. This tool is needed to fully compress the clutch’s diaphragm spring so you can remove and reinstall the stock clutch spring seat and clutch circlip. These parts go into a groove cut into the inner face of the clutch hub’s “fingers”. There’s no way to get these parts in or out of their groove without a spring compressor. I use many of Motion Pro’s tools for my builds and I use a Motion Pro for this one, too. Their tools are very well made and reasonably priced. And since we’re on the subject of the clutch spring seat and clutch circlip, be sure to check both of them as you replace the clutch plates. If either of these parts is distorted or their edges are worn, replace it.

 

Tools Needed
Blue Loctite
Thin flat-bladed screwdriver
Internal circlip pliers
T-27 Torx
3/16″ Allen
7/32″ Allen
1/2″ wrench
9/16″ wrench
11/16″ wrench
Torque wrench (in-lbs.)
Clutch spring compressor