Here is a quick guide that shows how to assemble the transmission on your Yardbeast 2090 wood chipper-shredder. This guide also works if you only need to change the belts.
1. First off, tools needed. We will use:
7/16" | 1/2" | 9/16" | 3/4" hex wrench (one of each).
1- Pulley extractor (optional, but handy).
1- Long straight edge (make it at least one foot long).
1- hammer or rubber mullet
1- piece of hardwood
2. What we will need:
1- Pulley with 1" tapered hub with 1/4" key
1- Clutch (NORAM 160023) with key.
1- Hex Bolt 3/8" x 1-1/2" NF grade 5. (black)
1- Hex Bolt 3/8" x 1" NC grade 5
2- 3/8" Flat washers
2- 5/16" Flat washers
4- 1/4" x 1" hex bolts grade 5 -black colored (2 are additional in case you need to realign pulley)
3. Clutch Assembly:
We'll start by assembling the clutch onto the engine. Slide the clutch (grooves facing the engine) on the shaft all the way. Align both the shaft and clutch keyways and insert the key that is provided with the clutch (shown below). Insert the key by hitting on the key mildly. It is important the key outer face reaches the shaft outer end.
Now grab the 3/8 x 1-1/2" Bolt and assemble with a 5/16" flat washer first, and then with a 3/8" flat washer and apply a dab of threadlocker to secure the fastener.
Screw the setup in place.
Tighten with one hand pulling gently on the starting recoil rope and the other with the 9/16" hex wrench in a clockwise manner.
2. Pulley Assembly
Now onto the rotor shaft. Insert then tapered hub into the pulley. Align the hub unthreaded holes with the pulley holes. Screw in the two bolts and tighten by hand. Do not tighten with tools yet.
Slide the the pulley and hub on the rotor shaft. Align keyways and insert key. If needed, hit the key mildly with a hammer. At this point the pulley should still be able to slide by hand, if not we can use a hammer and a piece of wood to correct position. Align by eye with grooves on the clutch.
3. Belt assembly
Insert the belts. First, make sure that the engine is pushed all the way closest to the rotor shaft. Insert the belts by placing the belt on the clutch grooves first. Then finish off by rotating the pulley and the belt will slip into position by itself. Make sure that your fingers doesn't get pinched between the belts and grooves!
Pull the engine away from the rotor by adjusting the engine bolt in a clockwise manner. Tighten until the belt looks firm. We will apply required belt tension in the next steps.
You will notice that when the engine is being pulled away, it will veer off because of the belt tension that is being applied. To correct, adjust the side bolt in a clockwise manner until the engine is straight.
To make sure the engine is straight, measure the length between the engine base face and the face of the chipper base. On each side . Variation allowed to our specs is 1mm or 0.04".
Now place a straight edge that touches the outer face of the pulley. Don't let the straight edge touch the clutch. Measure the gap between the edge and the belt along the length of te edge. To align, the gap must be the same along the length of the edge. At this point to you will correct the gap by moving the pulley in or out.
When the pulley is in the aligned position, make sure to move the pulley another 3/16" further in. The pulley will shift outwards this approx. distance when tightening the center hub.
Now, tighten the pulley tapered hub. It is best to alternate equal small amount of turns on each bolt to allow the tension to kick in and prevent bolt failure.
To apply correct tension we utilize a belt tension meter. Tension force required is 8lbs.
If you don't have such a tool, rule of thumb is to apply tension until the belt does not deflect more than 1/2" ( as shown in pic below).
Now that the belt is aligned and the belt has correct tension, it is now time to wrap this up.
Tighten the engine bolts.
And assemble safety fastener onto rotor shaft. Make sure to slide 5/16" flat washer first, and then a 3/8" flat washer. Apply threadlocker and screw in rotor shaft.
This concludes our guide to assemble the transmission on the Yardbeast 2090.