You don't. The belt tensioner is spring loaded.
If you look very very closely at the tensioner, there are wear-indicator marks that can confirm the belt has stretched beyond its useful life.
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If it is a drive belt and not a serpentine belt is has no tensioner. You manually adjust the tension by normally adjusting tension by moving the alternator. Loosen to bolts holding the alternator in place and then adjust the tension. Tighten the bolts when the tension is right. If it is serpentine belt if you follow the belt around the the engine you will see the tensioner.
The zd30 has a hydraulic tensioner using an idler pulley to automatically tension the serpentine belt.
if it is a serpentine belt, there is a tension pully that keeps it tight if is a v blet , u generally adjust the tension by moving the alternator
Some have a indent that fits 3/8 ratchet on base of arm
Serpentine belts have an automatic tensioner, which cannot be adjusted. But your problem sounds like poor alternator performance, have it checked, at your local parts store most do it for free.
There are a few different ways to adjust the drive belt or V-belt tension in a vehicle. The most popular used nowadays is a serpentine belt that connects to and activates every pulley in the engine. These serpentine belts require no tension adjustment as they incorporate an automatic belt tensioner. This type of tensioner has an internal pre-set spring and applies the correct amount of tension to the belt. Some older vehicles and some imports may use a combination of V-belts and serpentine belts in offset pulleys still controlled by the crankshaft pulley. Most often, there are belt tensioners on these vehicles that allow proper tension to be adjusted.
The alternator is usally on an adjustable slide mounted to the engine. If you adjust the alternator on that slide to take the tension off the belt you should be good to go to put the new belt on. The routing diagram for routing the serpentine belt should be on a placard mounted under the hood on the frame. It should also be in your user's/maintenance manual. Make sure to adjust the alternator properly on its slide mount so that there is sufficient tension in the belt.
Assuming you have a serpentine belt on that 3.3L engine, the tension on the alternator would be controlled by the idler (tension) pulley. The alternator is stationary.
If the tensioner isn't working right, you replace it. Tension is determined by the tensioner and is not adjustable.
No-there is one belt tensioner for the entire engine belt assembly. The timing belt is a serpentine belt and if it is stretched out, it will need to be replaced. There is no way to adjust the timing belt once it is put on the vehicle.
There is ( 1 ) serpentine belt used to drive the engine accesories : ( But there are different belts used depending on what engine you have " Vulcan " with air conditioning , " Vulcan without air conditioning , the DOHC " Duratec " engine etc. )
Basically, the timing is set and adjusted by the engine computer.