Replacing KTM Swingarm Bearings and PDS Heim Joint
No matter how much you look after your bike, components are going to wear out. And while it’s easy to see how your tyres or brake pads are wearing, then things like bearings are a tad more tricky. On the Ride Expeditions KTM EXC250, the rear suspension was beginning to feel decidedly off-colour. It was time to grasp the nettle, get into the garage and set about replacing KTM Swingarm bearings and PDS Heim joint
STRIP IT DOWN
So first off it’s time to strip down the bike. Although the job can be done without removing all of the subframe and assorted paraphernalia, it’s so much easier to access everything and inspect components if you go the extra mile and totally strip the rear of the bike.
So first off it’s time to strip down the bike. Although the job can be done without removing all of the subframe and assorted paraphernalia, it’s so much easier to access everything and inspect components if you go the extra mile and totally strip the rear of the bike.
With this in mind, we remove the seat, side panels, exhaust end can, battery box and electrical tray, disconnect the rear electrics and loosen the large jubilee clip holding the air intake boot the the carburettor.
This makes the four Torx bolts that secure the aluminium subframe easily accessible, and having first squirted them with a bit of WD40 and left for ten minutes, then they are loosened off and removed. Once done, the entire subframe with airbox and rear mudguard can be removed.
SHOCK AND AWE
Now we need to remove the shock absorber and swingarm, so it’s off with the two bolts at either end of the shock. You will notice we’ve left the wheel in place right up to this points as it keeps the bike chassis stable on the stand. Take it out and the whole thing wants to throw itself on the floor when your back is turned!
Remove and inspect the two bolts – they are both likely to be dry as KTM do not recommend and grease or lubrication on the two heim joints at either end of the shock. The bolts will need to be rubbed down or replaced as appropriate, but ours just need a clean up with some fine emery paper and then Scotch Brite.
ARMS OUT
Now we can remove the swingarm, so bebore that it’s out with the wheel and off with the chain. If you use a split link then it’s far easier to completely remove the chain and put to one side, rather than have it in the way. Support the weight of the swingarm on a another stand or chain as we have so it doesn’t crash to the floor!
Loosen off the swing arm nut on the left side of the bike, but leave on a few threads to start to move the swingarm pivot bolt with a hide mallet. Then find a suitable drift to continue to tap through the bolt until it is completely removed.
Remove the swingarm bolt completely and inspect it. On ours you can see that the left side – the chain side is significantly more rusty, suggesting that the needle bearings on this side have failed. Again the bolts is in reasonable condition so will need cleaning before replacing.
We put the bolt to one side and remove swingarm completely. Before we start on the process of removing the bearings, we also remove the chain guide and brake hose holder to make it easier to move around on the bench.
INTO BIKES AS MUCH AS US? WANT AN EPIC HOLIDAY?
OUT WITH THE OLD- STAGE 1
Before we can think about the new bearings, we need to remove all the old spacers and seals. The Heim joint has two identical spacers either side which can be easily tapped out, before the seals are prised out using a rubber shafted screwdriver.
This exposes the old Heim joint which can be seen is well past its best and badly needs replacement
We soak the bearing surface either side in WD40 or PlusGas and locate a suitable sized socket to allow the joint to be pressed out easily. At this point you may want to use some direct heat on the swingarm to assist the process, so use a blow lamp or hot air gun, but don’t forget it’s hot – cloth gloves are a smart move!
You can see that the joint is badly worn and corroded, but the outer surfaces are in reasonable condition.
OUT WITH THE OLD- STAGE 2
With stage one done, it’s now time to do the same with the swingarm bearings. They too have the same combination of spacers and seals with a couple of additional washers, but the bearings are far less robust needle bearings. Gentle persuasion and choosing the correct socket is essential to get a good push on the bearing surface – a 20mm socket is perfect.
The next step is to press out the old bearings. There are two on each side, and we use a larger socket on the opposite side to push the bearing out into. As before, we take our time on this and use a bit of direct heat on the swingarm to expand the metal.
CLEAN AND REPLACE
Now that all of the bearings are removed, it’s time to clean up the bearing surfaces and prepare them for the new parts, so it’s out with the fine emery and Scotchbrite to make them smooth and ready for the replacements.
We’ve already put all the new components into the freezer to contract them, and we warm the whole end of the swingarm to expand the metal suitably.
Needle bearings with internal needles have a flat side and a rounded side that the needles are loaded into before being sealed in, so when reinstalling we endure that the rounded end goes into the swingarm first. This way we can press the bearings into place against the flat surface. We use a larger socket this time as we don’t want the bearing to go in too far, so the larger diameter will stop the movement once the bearing is correctly positioned. Once one side is done, the second bearing is pushed in from the other side of the arm.
Once all four needle bearings are in place, that’s the hardest bit completed. Time for a cuppa!
For these bearings, we can now slather them in plenty of waterproof grease to ensure they are fully protected. We then fit the two washers to the chain side and then fit all four outer seals, leaving out the spaers as they will all fall out while we are fitting the new Heim joint!
Getting the correct order for the seals and spacers is essentials, and the parts finder on any KTM dealers website will not only give you what you need to order the new components, but also the order they should be installed.
HEIM AHOY
To finish things off, we need to fit the new Heim joint. Again we’ve kept the replacement in the freezer beforehand, and warmed up the swingarm to make it go in place easily. The joint needs to be central, so as it’s pressed into place with a socket as before we use a vernier to measure the distance from each side. Once correct, we can fit the seals and the two spacers. Note this joint is not meant to be lubricated as it’s teflon coated.
LAST LAP
On the final stretch now, so it’s time to push in the swingarm spacers and the top sections with a load more grease to keep things moving freely. After this the dust seal go in, but be careful as it is very easy to bend them.
Once done it’s time to offer up the swingarm to the fully cleaned and prepped mounts and then slide through the cleaned and greased swingarm bolt. The nut is then replaced and but not tightened until the shock is positioned
SHOCK BACK AND FINISH
With the swingarm now in place, we can replace the cleaned shock. You will notice we didn’t replace the top mount Heim joint as it had no play at all so could be left, but replacement is very similar to the bottom, but just with two circlips to remove,and far more care due to the more delicate surfaces of the shock absorber.
It’s time to tighten up the bolts to the correct torque, so it’s out with the the owners manual to check the figures. We nip up the swingarm bolts, then do the same to the shock bolts top and bottom, before returning to the swingarm pivot to fully tighten to the required torque, followed by the shock mounts.
JOB AND FINISH
The last part is to refit the subframe, remembering to remove the carburettor packing before reattaching the air filter boot. Reconnect all the electrics. replace the tank, exhaust, plastics and seat and fire the engine to check it still runs.
Time to get out on the trails and ride!
Job done then – and the suspension feels buttery!
PLEASE NOTE: THIS BLOG IS PRESENTED ONLY AS AN INDICATION OF HOW WE CHANGE THE SWINGARM BEARINGS AND PDS HEIM JOINT AND SHOULD NOT BE USED AS A DEFINITIVE GUIDE.
ONLY ATTEMPT ANY MAINTENANCE ON YOUR MOTORCYCLE IF YOU ARE COMPETENT TO DO SO AND HAVE SUFFICIENT KNOWLEDGE AND THE CORRECT TOOLS TO COMPLETE THE TASK SAFELY.
IF IN DOUBT, TAKE YOUR MOTORCYCLE TO A QUALIFIED MECHANIC.
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