OTC 4748 Belt Tension Gauge Tool Review -EricTheCarGuy

44 thoughts on “OTC 4748 Belt Tension Gauge Tool Review -EricTheCarGuy”

1. What do you set the O-Ring of the Gold Plated area to initally (how many inchs) when you place pressure on the Drive Belt.

2. Any two pullies points or does it have to be specific pullies

3. I think you need to watch this video to get an understanding of how the tool works. https://www.youtube.com/watch?v=S4a9z8ofNB8&list=PLQC1cX_1MCIvURs0Pmr_VJwOi9Rv2dwq7&index=20

4. It only shows 10lbs because that tool is made for Harley-Davidson belts and they are 10lbs. If you are doing cars, you might want the correct tool for that.

5. Linked second tool is just a go/nogo gauge basically

6. Having used half the deflection force, you've completely invalidated your measurement. The deflection force is THE most important number to have. You can get your "1/64th of an inch deflection for every inch of distance between pulley centers" at ANY belt tension, if you use enough deflection force. Go ahead…tighten your belt until it feels like a steel bar. Then take a crowbar and create a deflection. Oh, look…you got the right amount! The belt's about to snap and the shaft bearings glow when the car runs, but you got the right amount of deflection!

7. … I’m pretty sure I had some brain cells commit suicide just now… let’s turn 9/64 into a decimal then back to a fraction of 7/50, WTF

8. Do mechanics actually do all this or they just replace the belt and thats all? I mean, how would we know… Thought like this is what makes me waste a week on figuring this kind of stuff out, even though if I just worked any other job I would make more money and be less frustrated

9. That tool is specifically made for setting tension on A Harley Davidson Drive Belt LOL (maybe you found that out after 5 years lol)

10. Arrrg! "lbf" does NOT mean pound-feet, it means pound-force. Ie: One lbf is the force that gravity of earth applies to a one-pound mass. Which is the force that would register on a spring balance (for example) when it's used to measure a 1-lb mass. https://en.wikipedia.org/wiki/Pound_(force)

11. That is for a Harley drive belt. You need the Gates Krikit 91107. Their bigger one is 91132

12. You can also measure belt tension with a frequency detector app on your phone. How this works is you pluck your belt like a guitar string and measure it using the detector app. If it's too low you tighten the belt and if it's too high you loosen it. I know it sounds kinda crazy but that's how they do it at the Renault dealership.
    If your service manual doesn't specify the tension as a frequency, there's a formula that will allow you to make the conversion. You can find it online if you search for "belt tension to frequency formula".

13. mein got. you have NO idea what you're doing! and you make reviews for others. 'muricans at their best!

14. That's not "pound feet", it's pounds force. (As opposed to pounds mass. The English system tends to confuse them because technically weight is mass in slugs times acceleration of gravity in ft per second per second. But nobody uses slugs haha.) Cheers!!

15. That's a Harley final drive tool they are all measured at 10lbs

16. A very convoluted way when you're reading it the wrong way! https://youtu.be/S4a9z8ofNB8?t=77

17. I think I will just stay with the Dayco Criket tension gage.

18. Wow if you cant convert a decimal to a fraction ask a 3rd grader…better yet just use metric rule to measure the center to center distance, all Honda manuals have specs in metric & imperial.

    Convert the 1/64 to decimal , which is 0.015625 and 0.03937 inches per mm, so…………..
    0.015625/0.03937 = 0.400 mm,

    The 10 llb issue. If spec says 22 lbs & tool is 10 lbs then the tool will only deflect the belt about half the distance. So lets say 22ft-lbs gives 10mm of deflection so 10 ft-lbs will give about 5mm, actually its (10/22)*10mm =4.54 mm deflection. Just think of the actual weight pushing down on the belt, half the weight gives half deflection.

    Easy way to figure fractions to decimals, start at 1/4 = 0.250, easy right? Then keep dividing by 2, no calculators needed 1/8=0.125, 1/16th=0.0625, 1/32=0.3125, 1/64= 0.15625.

    Look at the numbers. half of 125 is 62.5 remember that because when you get down to 1/32 you see it again, 0.3125, so half of 30 is 15 and half of 125 is 62.5 so 1/64 is 15 +6.25 or 0.015625.The last 3 digits will always be 125 or 625

    Okay smart Johnny in back of the class, whats 1/125 equal to??????? Hint remember we already divide 1/16 to 1/32 and this division has same back half of each of those a 625 & 3125, if you got 7.5 (half the 15) + 3.125 (half the 625) =0.0078125. Both major and minor parts of the decimals keep repeating

    I was born in '55 and a true "imperial measurement guy but as I got into engineering the imperial system showed how bad it is, this is a prime example to the average Joe how screwed up it is. A mile 5280 feet, then a foot is in 12ths and an inch is in fractions that are not twelfths…what a wreck

19. extremly confusing.

20. Gates makes one that works for 22lb ft (just used it).

    Gates 7401-0076

21. There is a simple formula that you can use with this tool that makes it much easier to use. Given;

    1) Spec belt tension, T, in lbf (pound-force, or just pounds for everyday use),
    2) Distance between the center of the two pulleys, L, in inches

    Put the device on the belt in the middle of the span, and push down on the plunger until hits the "10 lb" mark. The amount of deflection you should get if belt is at spec tension (T) is given by the following formula:

    D= 2.5*(L/T) where D is in inches (assuming L is in inches and T is in lbf). I would round that to nearest 1/8"

    This formula can be derived by drawing a free body diagram of the belt and tensioner. FWIW I am a physicist and former physics professor – anyone who took freshman physics should at least be familiar with the concept. But in any case with this formula this becomes an easy to use tool. I agree that without such instruction, it's usage is somewhat obtuse! I just used it for the first time and had to do the above derivation to make sense of it – having done so it was easy to use and worked like a charm. I calculated ~1/4" deflection for my application (alternator , which resulted in a belt tension that "felt right" based on years or wrenching.

22. My T100 manual says a new belt that has run for 5 min. is considered a used belt.
    So I guess the used belt torque applies to a new belt ran for over 5 min.
    And new torque for new belt under 5 min. Brilliant eh. 😃

23. If I get kirkik tool it test the ftlb how much would it be on Honda accord

24. lbf is pound force, not pound feet.

25. interesting i also am aware of timing chain , time belt tensioner gages as well as the serpentine belt one your going thru. They also make universal ones that one should beable to use on all the types of belts and chains… though i questioning how good this is over just a little experience and tweaking to your liking.

26. You made the math more complicated than it needed to be, plus you don't need a calculator. At a rate of 1/64" per inch over a distance of 9 inches = 9 x 1/64 = 9/64" is just over 8/64" (which is 1/8").

27. Just multiply .140625 by 16 for 16ths 32 for 32nds 8 for 8ths etc. And it will tell you how many.

28. Just want to say you have saved me tons of $$$ by watching your videos. And the cars you work on are ones I own

29. You did your math wrong, your close but if your doing it for a 20lb plus oem spec then you need to multiply by 2 if your running a 10lb belt spec gauge. You should be getting different readings but not far from what your seeing, kudos on the tool tho I just do the belly up test for accessory belts

30. Take 10kg weight place in middle of belt.Use a straight edge and tape measure and texta.Pick a point of reference.You get it basically what this tool does.

31. what about the gates belt tension tool?

32. So when 10 lbs of force is applied on a belt that routes on two pullies which are 9 inches away from each other, the correct deflection you will see on the centre of the belt is 9/64 inches, is that correct ?

33. thank you man

34. Sorry Eric, but this tensioner tool from OTC is for motorcycles (which may explain why you had such a hard time with it). I purchased this same tool from JBTS and had to return it. OTC DOES have another auto belt tension gage tool, but much more expensive. I really like your videos and if I could politely recommend; Please do a bit more research on the tools you are hawking. Not all of us get free tools to review and sell.

35. This OTC tension gage tool is for motorcycles. I bought this tool and quickly returned it when I realized what It was. The automotive belt gage from OTC is $120!

36. This tool would be better if it had more force markings besides just 10 pounds.

37. Great video on how professionals do it. If your belt is too tight or too loose it will not last as it should. Incorrect tension is the biggest reason belts fail. Over tightening belts can cause bearing issues. Pushing on it with your thumb or twisting the belt 90 degrees is for back yard mechanics. Manufactures don't give specifications for a reason.

38. I dont understand the math, a 1/64 per ", for a 9" run, sounds like the deflection should be, 9/64".

39. I pity you poor Americans still lumbering away with the old Imperial measurements! Who do you have to lobby in your country to join the rest of the world in the 21st century with Metric? Regardless, thanks for all your efforts, I find you and a few others on Youtube invaluable.

40. its 3/4?

41. Now all you have to do is figure out how much your hand was moving, that's 4 fingers, minus 1 thumb, divided by 2 arms. Then you measure your height and weight and subtract, c'mon gimme a break here will ya. 😉

42. lbf is not "pound feet"  try pounds of force.

43. my grandpa said not to tight its all right lol ill fallow that

44. 95 people didn't get it ;]

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