how tight should the serpentine belt be?
Senior Member
Joined: Nov 2009
Posts: 577
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From: Mechanicsburg, PA
Year: 1996
Model: Cherokee
Engine: 4.0 L H.O. I6
x2 this is how i do it, works great.
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Joined: Aug 2010
Posts: 127
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From: Des Moines, IA
Year: 2001
Model: Cherokee
Engine: 4.0
From NAXJA
Does anyone know how to determine the serpentine belt tension on my '96 XJ? The FSM says something like 130-150 lbs. The only belt tension guages I can find are the ones where they wrench onto a spring pulley (n/a for XJ's). Pep Boys, Autozone, Kragen, etc. don't sell the type that I need. Seems sort of difficult to put a tensioner on the belt and pull on it until it reaches 150 lbs. Or is eye-balling it good enough?
This is similar to what I read, but it dosen't seem to be about the adjusting bolt.
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Does anyone know how to determine the serpentine belt tension on my '96 XJ? The FSM says something like 130-150 lbs. The only belt tension guages I can find are the ones where they wrench onto a spring pulley (n/a for XJ's). Pep Boys, Autozone, Kragen, etc. don't sell the type that I need. Seems sort of difficult to put a tensioner on the belt and pull on it until it reaches 150 lbs. Or is eye-balling it good enough?
This is similar to what I read, but it dosen't seem to be about the adjusting bolt.
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Last edited by irs009; Aug 12, 2010 at 05:26 PM.
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From: Smiths Station, Al
Year: 87
Model: Wagoneer
Engine: 4.0 I6
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Joined: May 2010
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From: SW Oklahoma
Year: 1988
Model: Cherokee
Engine: 4.0
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Joined: Aug 2010
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From: texas
Year: 1989
Model: Cherokee
Engine: 4.0 inline 6
I just put mine back together the other day from radiator , water pump , belts , hoses ect. surgery...I adjusted my belt and tightened it all down and flexed it and it seemed too tight...I got it set up to a half inch of play either direction or so....I rechecked it after 10 or 20 miles and its still good ....so half inch or so worked for me...
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From: Detroit, MI
Year: 1994
Model: Cherokee
Engine: 4.0
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From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
this has been a rule of thumb for years
Senior Member
Joined: May 2010
Posts: 889
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From: Detroit, MI
Year: 1994
Model: Cherokee
Engine: 4.0
I looked it up...there is no torque value for the adjuster bolt. The correct place to check for tension is between the PS pump and the water pump (or whatever pulley is next to the right of the PSP).
1/2" of play...or I like the 90 degree way and it is what I used. Then tighten all the mounting bolts to 20 pounds and you can forget about the adjuster bolt...it no longer is part of the "system". That's why there is no T value for it.
1/2" of play...or I like the 90 degree way and it is what I used. Then tighten all the mounting bolts to 20 pounds and you can forget about the adjuster bolt...it no longer is part of the "system". That's why there is no T value for it.
I shoot for just before an audible slip with the A/C on... The looser the better on the accessories... Belt deflection is just too tough to measure, not to mention the belt type and span distance play a hand in that measuring.
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Joined: Oct 2009
Posts: 244
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From: New York, USA
Year: 1996
Model: Cherokee
Engine: 4.0L I6
I'm no expert on anything, but I just want to say: guys, what ever you do but, PLEASE!!!! DO NOT put 125 ft lbs of torque on any bolts associated with belt, pulleys and anywhere near there 

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Joined: Nov 2010
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From: columbus ohio
Year: 1991 1999
Model: Cherokee
Engine: 6cy
for 99 cherokee sport
Install the new belt, and reverse the steps. The proper way is to use a belt tension gauge (adjust to 47Nm or 35ftlbs) -- but really, just make sure it's tight, but enough so you can move the belt up and down about an inch with moderate force. Hopefully, the original belt is properly tightened, so before you take it off, calibrate your hand
Install the new belt, and reverse the steps. The proper way is to use a belt tension gauge (adjust to 47Nm or 35ftlbs) -- but really, just make sure it's tight, but enough so you can move the belt up and down about an inch with moderate force. Hopefully, the original belt is properly tightened, so before you take it off, calibrate your hand


