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Belt Tension Question

#1

E

Eggbert

I find the manual a little confusing. If I set the spring length as per the manual, the belt tension is almost non-existent. There's also the question of where the measurement is to be made; between the hook ends, or just the coil length. Then there's the note about having it at 30 ft-lbs. Now why is this a torque reading for belt tension? What do they mean?

For the record, I think I have the belt set satisfactorily now, but I want to know more so I can set it the same every time. Understadning what the manual says seems a logical first step.

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#2

StarTech

StarTech

Which Husqvarna is this one? I need to download the owners manual and read it myself to see what they are saying.


#3

E

Eggbert

YTH24V42LS


#4

StarTech

StarTech

Downloaded the OM and I see what you mean it doesn't explain how the measure the ft-lbs. I would just ignore that as long you set the spring length correctly.


#5

B

bertsmobile1

Belt tensions are measured as inches of deflection per "X" pounds
And the X pounds are applied using a fish scale in the middle of the longest run .
Professionally they are done with a strain gauge which is basically one pulley pressing the belt down between two others
So if you were measuring the belt it would be 30 lbs/inch
Foot Pounds are a measure of torque and I am guessing that it is the torque on the bolt that should cause the spring to stretch to 5.5"
Spring stretch is always measured eye to eye on wound tension springs .
Spring pressure is also measured in pounds for 1 inch of deflection
So for instance my fork springs on the motorcycle are rated at 90 lbs

In the case of a deck belt it would be 5.5" extended length or 30 ft-lbs on the nut, which ever comes last
Remembering that wear on the pulleys themselves will make the belt run shorter and wear in the deck mounts may make the belt run longer on decks where you apply tension to the drive belt , or shorter where you stretch a spring to break drive to the deck ( Most MTDs where the deck moves ) .
So to cover all bases they give you wo ways to measure belt tension.
I for one ignore all this and tighten belts just to the point that you can make the engine do two full rotations by turning the blades .
Naturally this is glove on test and keys out of the ignition or better still, leads off the plugs .
Even then a engine wound up on full compression can spin backwards OUCH !!!!

I use the same test for drive belt tension .
It seems to do the job OK


#6

StarTech

StarTech

I wrote an email to Husqvarna asking what do they mean about this adjustment. This way I hope to get it clarified by Husqvarna. It will take a few days.


#7

M

MParr

bertsmobile1 said:
Belt tensions are measured as inches of deflection per "X" pounds
And the X pounds are applied using a fish scale in the middle of the longest run .
Professionally they are done with a strain gauge which is basically one pulley pressing the belt down between two others
So if you were measuring the belt it would be 30 lbs/inch
Foot Pounds are a measure of torque and I am guessing that it is the torque on the bolt that should cause the spring to stretch to 5.5"
Spring stretch is always measured eye to eye on wound tension springs .
Spring pressure is also measured in pounds for 1 inch of deflection
So for instance my fork springs on the motorcycle are rated at 90 lbs

In the case of a deck belt it would be 5.5" extended length or 30 ft-lbs on the nut, which ever comes last
Remembering that wear on the pulleys themselves will make the belt run shorter and wear in the deck mounts may make the belt run longer on decks where you apply tension to the drive belt , or shorter where you stretch a spring to break drive to the deck ( Most MTDs where the deck moves ) .
So to cover all bases they give you wo ways to measure belt tension.
I for one ignore all this and tighten belts just to the point that you can make the engine do two full rotations by turning the blades .
Naturally this is glove on test and keys out of the ignition or better still, leads off the plugs .
Even then a engine wound up on full compression can spin backwards OUCH !!!!

I use the same test for drive belt tension .
It seems to do the job OK
Click to expand...
I was thinking along the same lines. Using a torque wrench put in the square that is punched in the pulley bracket. You certainly have to apply more than 30 ft.lb. in order to remove the belt.


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