Identifying 1977-1978 Polaris RXL Shock Absorbers
These are getting harder and harder to find, and it’s even tougher trying to explain what you need. Hopefully this guide helps.
a little video to explain it all
The Original IFS SHocks
For the first few weeks of their existence, the 1977 Polaris IFS Snopros had the shocks pictured here. That’s Gordon Rudolph kneeling next to Brad Hulings 1977 440 and you can see the upside down shock that does not appear to have a spring on it.
These were made at Polaris, but they collapsed in very cold weather and wouldn’t come back up, so they were all ditched for commercially available shocks before the team got to Eagle River in January of 1977.
As of this writing, none of these shocks survived. I, for one, have never seen one in the real world.
First and Foremost...
The shocks from around Eagle River in 1977 through the 1978 season were the same on all the machines except for the spring length.
The top of the spring MUST fit in this top spring retainer, which is just 2″ wide. The bottom of the spring is 2.5-3′ wide.
A spring that is the same width on the top and bottom is NOT an RXL spring.
The 250 and 340cc machine shocks
On the machines with a twin-cylinder engine, you can do a rough count of the coils on the spring of the shock.
The recoil side will have 10 coils.
The clutch side will have 13 coils.
That may seem backward, but the recoil side will have Centrifugal force holding that ski down to the ice, so that outside ski needs the extra coils to keep extra pressure on the inside ski.
Pictured here is Brad Hulings 1978 340, and you can actually count the coils in the photo.
The 440cc machines
I just learned this from Brad Hulings a few months ago: The 440s all had the same shock spring on both sides, because of the weight of the triple engine.
Both sides on a 440 have shocks with a coil count of 10.
There ya have it! If I find out more I’ll add it to this post.