An Easy Method to Fine-tune A Primary Chain

The design of a Big Twin's Powertrain is non-unitized. Specifically, the gear box is mounted apart from the engine, meaning the two should work side by side in order to pass power. This is where the primary drive, inside that huge aluminum case next to the biker's left boot, takes into action.

From the name itself, the main drive passes power from your engine to, ultimately, the backend wheel. The reciprocating power that’s provided by the engine’s crankshaft is transformed into rotating power through the running major chain and sprockets that spin the transmission’s input shaft. Once the energy regroups within the transmission it’s spread from the gears and into the supplementary drive, which is the chain or belt drive that turns the bike's rear end tire. This is a brief description of a Harley powertrain, and, basically, each part takes on an integral part in moving you and the bike around the highway.

Being that the powertrain is made up of a group of moving components, you’re going to have to carry out regular adjustments to them so they will work properly. In time, moving parts, just like the main drive’s sprockets and chain, degrade. As things wear, they need adjustment to help maintain correct tolerance. And it’s the main driver’s multi-row roller chain that must be looked over and fine-tuned once in a while. It’s a fairly easy procedure, at the same time, a method that you can do in your own garage or shop.

Many of the action comes about around the inspection window that is reached by taking out the plate secured on by four screws. You will need to have a ruler to make the sizing and a set of essential tools to perform the adjustments. To adjust, release the adjusting shoe’s 9/16” bolt a few turns and rotate the shoe upwards to tighten the chain or downwards to loosen.

A good time to examine and adjust the main chain takes place when you have to drain and replace the primary case oil. Harley Davidson suggests its versatile synthetic oil, however, if you already have a desired brand that’s been produced for the primary drive, by all means, use it. Just make sure no matter what oil you decide is designed for this function.

When you have removed the inspection plate, you've got a good view of the chain’s components related to it, so makes use of the time to check them for wear. Look at the chain’s rollers to find out if they are receiving total lubrication, and check the adjuster shoe for breaks and such. Inspecting and fine-tuning the main chain is quick and easy, when you’re finished you can have one thing of the checklist of things to do on your next drive. Remember to replace the inspection plate gasket.

Things You'll Need:

Pipe sealant
Drain pan
T27 Torx
T40 Torx
9/16” deep socket
Ratchet
Ratchet extension
Ruler

1. Basic care such as fine-tuning the primary chain can be executed in your own garage or shop when it’s time to change the primary oil. Be sure the motorcycle is fixed in an upright stance once you begin.

2. The first thing to do is usually to drain the main case of its used fluid. After placing a drain pan beneath the primary, work with a T40 Torx to take out the drain plug which is positioned just beneath the derby cover.

3. Leave the used primary fluid to drain into the pan. While it drains, you can easily inspect the main chain to find out if it needs tuning.

4. Use a T27 Torx socket to get rid of the 4 bolts that hold the primary inspection plate in position. It’s smart to change the inspection plate gasket before you install the plate.

5. While the inspection plate is removed, you can examine the chain’s rollers for signs of wear. Try inspecting them for hints of damage. With the transmission in neutral, spin the engine a little bit several times so you can see the whole chain.

6. While checking several places in measuring the chain, always note doen two readings. First is with the chain’s top run at slack. Second, the ruler is raised from the top run to remove the slack and to measure once again. The main difference within the 2 at the chain’s tightest point is definitely the chain’s slack.

7. Work with a 9/16” deep socket to fine tune the chain’s free play. With the chain cold, fix the free play between ½” and 7/8”. After you have tightened the nut again, measure the slack again to ensure that you have established the proper amount.

8. Since the inspection plate is open, additionally check out the adjuster shoe that is pushing against the chain’s under run. On the upper right corner, you'll find the adjustment nut.

9. Not like the motor and transmission drain plugs, there’s no O-ring on the primary case drain plug. To aid in sealing it, rub a little pipe sealant along the base of the bolt.

10. Soon after you're done clearing off the oil from the main cover, re-install the main case drain plug. When already set, carefully twist the inspection plate's bolts as well as the derby cover bolts to 108 in-lbs.

11. You can now fill up the primary case with clean fluid. Many mechanics use lubes from the big barrel rather than retailed canisters.

12. Fill in 32 oz . of fluid. Add the right amount for your year and model bike.

This year, bike runs are set to kick off from various states. A multitude of bikers will be congregating for one week of celebration all expressing their fascination with motorcycles. There will be a lot of stories and building tricks to recommend with brand new mates while you ride the days the time in
while in the bike runs. Ensure that you drive safe and slip on the necessary safety equipment like carbon fiber helmets. Good luck and have a fantastic run.