Steve Schefer (On Taunton Forums) The subject of this discussion applies to most all Contractor saws not just Jet. If you've ever tilted your blade over and hit your outfeed table, you need to read this. This is not a common sense thing its a hidden danger.

The gearing on the tilt mechanism is of a ratio that will allow you to serously rack the trunion out of alignment if your forget about the motor to extension table clearance and the motor hits the table during the tilting operation. If this happens to you, stop using the saw immediately. The likely hood that the parallelism of the blade is out a seriously dangerous amount is very high.

Checking the parallelism at 0 tilt is not good enough. If you only check it at 0, you can be very unpleasantly informed by flying lumber that it is way out at a 45. This happens because the trunion stretchers are tweaked. Loosening up the four trunion bolts and realinging will not correct this.

To fix a saw that has been damaged in this manner is tedious but it will save the saw and at least one 98.6 deg puddle of body waste fluid on the shop floor.

Here's how its done....
Preliminary ...... DISCONNECT THE POWER TO THE SAW ..........
1. Remove the motor belt guard
2. Lift the motor and remove the belt.
3. Place a board of sufficent length between the motor and the floor so the motor sits level.
4. Remove the electrical connection to the motor.
5. Remove the motor mounting bolts and lift the motor off the bracket.
6. Loosen the two large trunion stretcher nuts at the rear trunion.
7. Loosen all four trunion to table bolts.
8. Vigoursly shake the trunion assembly.
9. Tighten the two large trunion stretcher nuts that you loosened in step six.
10. Raise the blade to its full height at 0 tilt.
11. Place a piece of masking tape at the front of the blade.
12. Grasp the front and rear of the blade and pull it towards you until it stops.
13. Mark the tape on the side of the blade closest to you.
14. Grasp the front and rear of the blade and push it away from you until stops.
15. Mark the tape on the side of the blade furthest from you.
16. Place a mark on the tape that is centered on the two previous marks, (split the difference). 18. Center the front of the blade with the third mark.
19. Tighten one of the front trunion bolts just enough to keep the front trunion at its current location.
20. Place a piece of tape at the rear of the blade.
21. Grasp the motor mount and swing the trunion towads you. 22. Mark the rear tape on side of the blade closest to you.
22. Push the motor mount to the opposite side.
23. Mark the tape on the opposite side of the blade.
24. Place a mark between the two marks and split the difference.
25. Grasp the motor bracket and move the trunion so that the front and rear of the blade are centered on the front and rear center tape marks.
26. Tension the rear trunion bolt on the oposite corner from the front trunion bolt you tensioned earlier.

You are now at zero reference for your table and the trunion is in a relaxed state. You can now dial in the blade paralellism.
1. Use a dial gauge in the miter slot and check the distances along the entire lenght of the blade.
2. Lightly tap the rear trunion with your hand to move it to either side until you are satisfied that the distance variation is within manufactures specifcations or better.
3. Tighten all four trunion bolts.
4. Tilt the blade to 45 deg and check the distance front to rear again. It should be exactly the same as it is at 0 deg. If its not you may have a problem.
5. Return the saw to 0 degrees of tilt.
6. Put the motor back on being careful to align the motor and arbor pulleys.
7. Put the belt back on.
8. Tilt the blade to 45 degrees and check the distances front to rear. A large change from front to rear is an indication of a cracked trunion that is separating from the weight of the motor. DO NOT USE THE SAW UNTIL IT IS REPLACED. Mine moved -.0009 front to rear which I consider very acceptable and likely just slop in the tilt mechanism.

************************** Dizzy Racking the trunion is fairly easy to do, especially if you have an outfeed or have the back blocked off for dust collection purposes.

Don't know what all the tape is about he mentions, but bascially the guy is loosening everything up, shaking and "hoping" the assembly goes back in alignment. If you look at the anatomy of the trunion assembly you'll know what I mean.

The critical part he left out is "clamping" the main trunion assembly to the trunion brackets during re-alignment. These two mating parts ride in a radius'd tounge & groove (allows trunion assembly to tilt).

If both the front and rear trunion brackets (brackets that bolt to underside of table) are loosened, these brackets can spread apart resulting in a gap in the mating tounge & groove which holds the main trunion assembly (i.e. you will have slop between the two). You can set your alignment at zero, but then when you tilt the saw that alignment will can go out and be off again even after returning to zero. Reason I always say never to loosen the hard to get to front bracket when aligning the saw. Your only moving the rear a few thousandth's when you're aligning the saw.

When un-racking the trunion, you need to check the front/rear main brackets so they are coplaner with each other (these are held together by the trunion rods), this means some measuring from the underside to a reference point to be sure (or removing the complete trunion assembly and aligning it on the bench). Once these two brackets are coplaner with each other, then the trunion rods can be tightened back up and torqued. The only real way to be sure you have alignment on the tilt is to have some precision wedges or an alignment device such as the TS-Aligner Jr. which can check the heel & toe alignment on the tilt.