Pull the cover off an EBS-style Polaris secondary and you will find a rubber dampener tucked into the clutch. It is one of the least expensive parts in the entire CVT, it gets almost no attention, and it is absorbing a shock load every single time you lift off the throttle.
What the Dampener Actually Absorbs
On an EBS (engine braking system) secondary, the clutch is doing more than squeezing the belt on the way up. When you close the throttle, engine braking reverses the load path — the wheels are now driving the engine through the belt, and the secondary has to grab and transmit that reversal. The dampener sits between the rotating parts and takes the impact of that load flipping direction.
Every deceleration is a hit. Every time the clutch loads back up coming off a downhill, that is another hit. Add a big bore engine, added weight, oversize tires, or a rider who uses engine braking hard on descents, and the number of load reversals per hour climbs fast.
How You Know Yours Is Done
A tired or cracked dampener usually announces itself as a knock, clunk, or rattle from the clutch cover that shows up in the transition — on and off throttle, in and out of engine braking, or crawling at very low speed where the clutch is cycling constantly. It is easy to blame a driveshaft or a prop shaft u-joint for the same noise, so before you start throwing driveline parts at it, get the clutch cover off and look at the dampener.
Once it is apart, the diagnosis is simple. You are looking for cracks, chunks missing, hardened rubber that has lost its give, or a dampener that has broken into pieces. Stock dampeners are known for cracking and breaking, and once one lets go, that shock load goes straight into the parts around it.
The Upgrade
The HD Polaris Secondary Clutch Dampener is a direct replacement for the lower quality stock piece, built specifically to resist the cracking and breaking that kills the factory part. At thirty-five dollars it is one of the cheapest pieces of insurance in the whole clutch.
Fitment
It can technically be used on all Polaris vehicles with the EBS style secondary clutch, but it does not fit 2016 models. It is primarily used on 2014-2015 RZR XP 1000s and on RZR XP 900s with big bore engines, and it is also used on the RZR XP4 900 and RZR XP4 1000. If you have one of those machines and you have never had the secondary apart, assume the dampener is original and inspect it.
Plan the Job Before You Start It
One important note: a secondary spring compressor is required to install this. The secondary carries real spring preload, and it stays loaded whether the clutch is on the machine or sitting on your bench — this is not a part you can safely get to by clamping the clutch in a vise and backing bolts out. If you do not already have one, the Hunterworks Clutch Spring Compressor Tool handles both primary and secondary clutches on Polaris models and will make this a controlled twenty-minute job instead of a gamble.
Since the secondary will already be open, do the rest of the maintenance in the same sitting. Inspect the rollers and their bushings for flat spots and play, look the helix over for wear on the ramps, check the sheave faces for grooving and glaze, and clean everything before it goes back together. Doing a thirty-five dollar dampener and then closing it back up over worn rollers is a wasted afternoon.