Auto Belt Tensioner Mod/Replacement


My auto belt tensioner was getting a little slack and causing belt squeal. A temporary fix was to jam a 3/16 screw in behind the spring end. Can see the screw here adding more tension by forcing back the end of the spring away from the old stop in the opening.


LHD's did not have this setup and you cannot buy a replacement tensioner anymore, so I swapped everything over to one year later 96 model. Later years and ZJ and ZG 4.0 models might also work. It is a big cast iron bracket instead of the light cast alloy one. Many thanks to Jason for gifting the bracket and bolts to me. :) Make sure you get all the bolts, pulleys and belt tensioner screw and bolt arrangement. Bolts are different lengths and even thread in places. The 96 model and many later ones have the alternator up higher which I prefer away from the muddy water.


If stock you can just run the belt the same as the 96 model. The problem you face, if running two electric fans having removed the old fan hub, is that it interferes with one of the timing bolts seen below the alternator above. Running a longer 6PK2305 belt will mover it out of the way.


Alternatives are using the old idler pulley mounted on top of that timing bolt boss to deflect the belt away from it. Just need a longer one to hold the pulley in place. If you want more belt wrap around the crank and alternator, run a smooth pulley instead like this. I swapped the old 95 pulley where the 96 one was and ran the 96 on the timing bolt boss. You do need to cut off the old lower boss from the bracket though as you can see it hit it in this photo.


As I was fitting a physically bigger 132 amp alternator, instead of the 90 amp stock one, it pushed the pulley across far enough to clear the bolt anyway. To workout what belt length I needed, I just cut the longer old one and pulled it tight and marked the overlap. Then just measure how long it is. Part number will be 6PK, (6 ribs), follow by the length in millimetres. In this case I measured 2310mm but they had none in stock so manage to squeeze on a 2305mm one. 6PK2305.


Clears the bolt just fine. The power steering pipes did have to be bent to sit on top of the tensioner bracket where a hole was drilled and tapped to hold it in place. Basically I straightened a bend out where it use to bend towards the hose about where is passes by the hose clamp.