Table saw blade adjustment

[wannabedivin]

I have an older belt drive table saw. When the blade is at 90 degrees the up and down adjustment is virtually impossible to change. If I back the blade off by a couple of degrees everything is as it should. Thoughts

[mike4244]

I have an older belt drive table saw. When the blade is at 90 degrees the up and down adjustment is virtually impossible to change. If I back the blade off by a couple of degrees everything is as it should. Thoughts

Back off the 90° stop bolt to see if this remedies the problem. Might be hardened dust on the crank screw. Scrub the screw with a brass brush or even an old tooth brush. I use Dricote spray on areas that are prone to wood dust. Grease attracts dust , WD-40 works but does not last. 
Is the adjustment difficult at any blade height or just when the blade is high? Are you sure the blade is at 90°? If the arbor is past 90° the trunnion might bind. Then set the blade at 90° , clean the stop bolt and snug the bolt up til it just touches.
I once had a problem where the blade would not go to 90° , the crank seemed a bit tight too. I removed the blade and insert. Turned the saw upside down on a plywood scrap. Then did all the stuff I recommended above. This worked well. This saw was an old Craftsmen 10" saw with a cable drive. 
mike

[wannabedivin]

Back off the 90° stop bolt to see if this remedies the problem. Might be hardened dust on the crank screw. Scrub the screw with a brass brush or even an old tooth brush. I use Dricote spray on areas that are prone to wood dust. Grease attracts dust , WD-40 works but does not last. 
Is the adjustment difficult at any blade height or just when the blade is high? Are you sure the blade is at 90°? If the arbor is past 90° the trunnion might bind. Then set the blade at 90° , clean the stop bolt and snug the bolt up til it just touches.
I once had a problem where the blade would not go to 90° , the crank seemed a bit tight too. I removed the blade and insert. Turned the saw upside down on a plywood scrap. Then did all the stuff I recommended above. This worked well. This saw was an old Craftsmen 10" saw with a cable drive. 
mike

Thanks for the input.  I already backed off on the stop screw (in fact I took it out to be sure).  The up and down  adjustment is only hard at the 90 degree point. Along the same lines, getting to 88.5 is easy the last 1.5 degrees is really hard.  I have verified the 90 degrees with both a square and and electronic angle gizmo.  I will look closer at it later tonight

[mike4244]

Thanks for the input.  I already backed off on the stop screw (in fact I took it out to be sure).  The up and down  adjustment is only hard at the 90 degree point. Along the same lines, getting to 88.5 is easy the last 1.5 degrees is really hard.  I have verified the 90 degrees with both a square and and electronic angle gizmo.  I will look closer at it later tonight

I thought of one other possible reason after I posted. Do you have a Vega fence on your saw? I recall at least one customer , at now defunct Wood Workers Warehouse where I worked after retiring telling me the same thing as your problem. I called Vega Fence , they had an easy fix. 
I do not recall as this was 20+ years ago.  He told me that that the height adjustment was fine til he added the fence. When I talked to a tech he told me it problem may be related to the fence. The fix was easy according to the customer. An easy test for squareness to the table is to run a scrap board thru the middle and against the fence. Flip one piece over and butt it to the other. If the boards show a gap then the blade is not at 90°. 
E-mail  remvega@aol.com
Phone#  1 217 963 2232
mike