Changing Suspension Oil For Back Shocks On A Dirt Bike – Part 2

In this post let’s look at changing the oil in the rear shock. For this project, we’ll mainly need basic tools and later on, we’ll need a few specialty tools as well. The first step is removing the seat in the right-side panel then we’re going to remove the three bolts that hold the muffler on and remove them off from the bike.

To access the shock we’ll have to remove the four subframe bolts so the subframe is loose. On the linkage, we’ll remove the rear connecting arm bolt and then we’ll just weaken that connecting arm down away from the rear shock. In order to get the bolt out, you’ll have to lift up on the rear of the leg while pushing the bolt out. The next step is to remove the lower shock bolt, you’ll have to lift up on the rear of the bike to get this bolt out also.

Before you remove the top shock bolt you’ll have to loosen up the two spring nuts. You can use a screwdriver and a hammer to loosen up the nuts. Before you loosen up the spring measure the length of the springs so you know where to set it at when we’re finished. Once the top spring nut is loose you can just grab the spring and start spinning it this will loosen the spring the rest of the way.

Once the spring is loose you can remove the top shock bolt. To remove the shock from the bike you’ll just have to push the subframe out of the way and pull the shroud out and shock should come right out. Make sure your air boot clamp is tight when you push this subframe out of the way to get the shock out. Now with the shock off the bike, you’ll want to make sure the spring nuts are all the way at the top of the threads.

To remove this spring from the shock you’ll have to pound the outer ring upwards to expose the clip. It’s best to use a soft hammer and a screwdriver for this. Once you can get to the clip remove the clip and the outer ring and spring should slide right off the shock.

The next step is a route with a valve stem cap and release all the nitrogen out of the bladder using a valve stem core remover. Once the valve stem core is output the cap back on to protect the threads. Now we can remove the compression adjuster from the shock. Once that’s out we can dump the old shock oil into a drain pan it helps the pump the shock shaft when you’re dumping the oil out of the shock.

When you’re dumping the oil out there’s a small plate that will come out as well make sure to keep track of that. After that, we can add new fluid to the shock. To bleed the shock of any air bubbles pumps the shaft several times. Once you’ve done that hold the shock at an angle so the hole is at the highest point and fill the rest of the shock with oil then install the valve stem core and add a few pounds of pressure to the bladder.

You just need to add enough pressure to where the bladder cap comes out of the shock body. Now it’s time to install the adjuster and the plate back into the shock body. The plate goes in first with the flat surface facing up as shown, tighten the adjuster up and wipe all the oil off the shock. Once the adjuster is tight release any pressure from the bladder. Now the spring can be installed back onto the shock.

Most springs usually go on only one way so make sure you get it in the right way. Once you slide the spring onto the shock put the outer ring on and install the clip, take a soft hammer and seat the ring with the clip. Once the shock is finished you’ll have to have the bladder recharge with nitrogen gas the recommended pressure for this shock is 142 psi.

Most motorcycle shops should be able to do this for you it will cost probably 20 or 30 bucks. The next step is to install the shock back onto the bike so you’ll have to push the air box out of the way and move the shroud to get the shock in. It’s easiest to install the upper bolt first then the lower. You’ll have to lift up on the rear of the bike to get the lower shock bolt in.

On this bike, you have to tighten the lower shock bolt before you install it connecting your arm back on. The torque spec on the lower shock bolt is 32 foot-pounds. The rear connecting arm bolt can then be installed you’ll have to lift up on the swing arm to get the holes to line up. Once the linkage is back together you can reinstall the subframe bolts.

The torque value for the upper subframe bolts is 24 foot-pounds and the spec on the right lower subframe bolt is 36 foot-pounds and for the left lower subframe bolt it’s 24 foot-pounds. The next step is to reinstall the muffler, on the rear muffler bolt there’s a washer that goes in between the muffler and the subframe so make sure to install that. Now we can install the side plate and the seat back on the bike.

The final step is to take the bike out the stand and compress the rear suspension several times. This helps line up and settle the linkage and the rear shock. The rear shock and the linkage bolts should all be loose when you’re doing this. Then we need a torque all the shock and linkage bolts.

The torque specification on both the lower and the upper shock bolts is 32 foot-pounds and the spec on all three linkage bolts is 39 foot-pounds.

That’s it for this project changing the oil in both the shocks.

Recent Posts