This thread explains the procedure for modifying the K6 accessory belt routing such that the tensioner and idler pulleys, along with their associated brackets, may be deleted. In what follows it is assumed that the A/C system has been deleted and that A/C compressor has already been removed from the car.
Preliminary notes:
A new accessory belt is needed. Gates/Napa/Carquest #060390 works. Because this modification eliminates the tensioner, the belt must fit perfectly. The next size up, #060400, is too large. Most parts stores will have 390 or its equivalent; it is a fairly common belt. Final belt tension is a touch tight.
Preparatory disassembly
Remove the following:
Driver’s side wheel
Driver’s side inner wheelwell plastic (to expose crank pulley and accessory belt tensioner)
Driver’s side intercooler outlet pipes and hoses where they cross over alternator
Driver’s side intercooler inlet hose
A/C fan (if vehicle so equipped)
Electrically disconnect the alternator
Remove the two bolts securing the power steering cooling loop to the frame rail. It is necessary to push these lines down in order to easily remove the idler pulley.
Primary disassembly
Remove the tensioner pulley and bracket. To take off the pulley, fully remove the center bolt. Then, remove the bracket. There are 3 bolts. Next, remove the idler pulley center bolt and then remove the idler pulley. Then, remove the A/C compressor bracket. It is held in place by 6 bolts
Tensioner bracket
A/C bracket
Note: It is probably possible to remove the A/C bracket and idler pulley together, but that makes for a few awkward reaches and a more awkward piece.
Remove the alternator assembly (alternator + bracket). It is held in place by two bolts near the front valve cover and two bolts on the front (i.e. timing-belt side) of the engine.
Lower the assembly down until it rests on the crossmember. It is not necessary to remove the assembly from the car. Be cautious not to strike the radiator with the alternator.
Remove the smaller bolt and the nut and crosspin holding the alternator itself to the bracket. They should not be difficult to break free and the crosspin should come out easily. However, the bracket may not freely separate from the alternator. Wiggle it back and forth and be patient.
Modifying the alternator bracket
Using an oxy-acetylene torch, severely compromise the structural integrity of the bracket by removing about 2/3 of the boss for the lowermost bracket-to-engine mounting hole. Complete with a bench grinder, making sure to round off the corner beneath the adjacent boss. The belt will ultimately pass very close by here; if you do not remove enough material, there will be interference. Take off a little more, rather than a little less.
Installing and tensioning the new belt
Put the modified bracket back on the alternator and reinstall the crosspin and lower bolt. Leave them loose to allow maximum alternator movement. Install the alternator assembly on the car using only the modified boss mounting hole. The stock bolt will be to long; use a M8x1.25 bolt 20-30mm long bolt (depending on how much material you removed) as a replacement. Leave this bolt somewhat loose as well.
The alternator can now be pivoted down, though the close fit of the alternator bracket and the L-bracket on the head near the dipstick makes this difficult. Use your hands to rotate the alternator down.
Install the new belt (060390) on the crank and alternator pulleys.
Tensioning the belt requires a Mitsubishi special tool (tool number M1366590 Revised Routing Tensioner), as shown below.
Using the special tool, raise the alternator until the mounting holes on the bracket line up with the holes on the L-bracket. Install the bolts.
Finally, reinstall the other alternator bracket mounting bolt and tighten the bolt and the crosspin nut holding the alternator proper to the bracket.
Reinstall the parts listed above under “preliminary disassembly”
Assorted photographs of new belt routing
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Additional photographs of alternator bracket
Stock:
Modified:
Parts deleted
Clint