all of the pictures are of my m62tu. your car may be slightly different.
the belt tensioning systems on these cars are very easy to use and set if only you know how to operate them correctly.
1. the first thing we do is draw out the path of the belt and the location of all the pulleys so that we know if we put it back together correctly or not.
this is the main belt with the correct routing:
here is my map that i drew:
here is the a/c belt correctly routed:
2. the next step is to loosen the belts. you need to locate the tensioner and the bolts that hold it on.
this is the a/c tensioner
this is the main belt tensioner:
to loosen the tensioning device you need to loosen two bolts the first is the bolt in the slotted area. on the main belt tensioner it will be a 13mm and on the a/c bet tensioner it will be 10mm.
the second bolt that needs to be loosened is the pivot bolt. the pivot bolt will be a 13mm on either tensioner. the bolt head is the smaller bolt resting on a larger nut that is part of the tensioner itself.
now that the tensioners are loose the belt will just slide right off.
3. before reinstalling the belt wipe all the pulley contact surfaces to make sure they are free of grease from your hands. you should also go inside and degrime your hands before touching the belt. how mad would you be if the belt slipped or squeeled because you got it contaminated with oil?
refer to you drawing and replace the belt.
tip: the smooth pulleys only ever touch the flat side of the belt and the grooved pulleys only ever touch the grooved side. if you have grooves touching flat anywhere you did the routing wrong.
once the belt is on try wiggley the pulleys a little bit to make sure the belt is seated in the grooves and not crossthreaded anywhere.
tip: the a/c goes to the back so make sure you put that one on first.
4. to tension the belt correctly your will need to torque the tensioner around until the bolt in the slot is maxed and cant go anyfurther because there is no slot left.
i will start with the a/c pulley. this one is a little tricky because is has a second pivot point and tends to flip inside out when you are trying to get positioned.
what you will do is put a 17mm socket on the large pivoting nut and turn the entire tensioner by turning the socket until the 10mm is maxed out in the slot. while holding tight use a 10mm box wrench in your other hand to tightened the bolt in the slot. make sure it is tight enough that when you let go of the ratchet the slot doesnt slide then tighten the 13mm pivot bolt where your 17mm was a moment ago.
on the main belt things are pretty much the same except that its upside down and doesnt have the second pivot popping out on you.
note that in this pic of the main belt tensioner i provided leverage with the 17 wrench and not the ratchet.
i used the 13mm ratchet to tighten the bolt in the slot. on this tensioner there is very little slot so you dont need to turn the unit that far until the slot is maxed out and properly tensioned.
at this point you are finished. check the belts one more time so see if anything looks twisted or out of place.
check both tensioners to see if there are any other loose bolts or nuts that could be tightened to help keep the tensioner from working the slot loose.
on mine i had to also tighten these although i dont remember loosening them. they will help keep the pivot locked in place so it doesnt loosen:
Bookmarks