Loose or Broken Crankshaft Pulley Bolt on Mitsubishi Montero

Problem Description and Possible Solution

The crankshaft pulley bolt may become loose or break causing loss of power steering operation and other related engine accessories. Some of these vehicles may be involved in a recall for this issue. Our technicians tell us that an updated bolt may be available. Replacing as necessary and properly torquing the crankshaft bolt will commonly correct this issue.

Problem Data
RepairPal Verified
Average mileage: 174,052 (80,000–275,000)
Engines affected: 3.0L V6, 3.5L V6
17 model years affected: 1990, 1991, 1992, 1993, more1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006
66 people reported this problem
Viewing 1 - 20 of 29 comments
the roll pin holding the crankshaft pulley to the timing sprocket broke, probably due to loose crank bolt.
crankshaft pulley loose and wobbling, mechanic says this is very expensive to fix if can be fixed at all. Many have this problem- please report if you do because this should be a recall
On my 97 montero ls 3.5L, my harmonic balancer has alot of slop in it and the bolt holding it on it tight. I have no way of removing that bolt. Any suggestions?
This same problem happened to me when I bought the truck at 196000 miles for $600 bucks, and a thousand miles later the crank pulley pin sheared too, twice in little less than a thousand miles. The last time I was stranded in a busy intersection with my wife and daughter. To those out there experiencing the same problem try this, try to drill a second pin hole in the pulley at the same exact location but in the opposite side of the first pin hole, and instead of having one pin you now will have two pins holding the crank pulley. One on each side of the crank pulley,so that crank pulley can stay locked in place, but make sure you use the strongest thread locker.I think I have figured it out. This is just my idea to do it my self, but you can talk to a mechanic and see what they tell you. I am about to do that to my crank pulley hope I fix it for good, and I hope you too. 01/17/14 Eddy
This is the second time the crankshaft pulley bolt has sheared off in the engine. I don't know why it keeps happening.
bolt came loose on the crank shaft leaving me stranded at the store, sheared the roll pin, now im on my way to the junk yard to find another one,
Original Crankshaft Bolt broke. Symptom: Engine Temp was slightly higher than normal, strange noise up front.

[NOTES: First, I removed the Fan Blade. Then, the Radiator. Then the Fan Belts in order to gain access to the Harmonic Balancer & Crankshaft do this. I did not use a lift.]

Drilling out the original (RECALLED in '2001) Bolt. Used a *Left-Hand Drill Bit* & the broken piece came out. NOTE: Made a "Tap Guide" out of some nuts, so that I could drill in the center of the Bolt (& perpendicular too). Don't be in a hurry with this! Take your time. Use some Cutting Oil (Harbor Freight).

Purchased the proper (new type / design) from a Mitsubishi Dealer ($16.00) with Washer. IMPORTANT: Get Torque Spec. from Dealer, or on - line. This is *very* important.

REPLACE THE Harmonic Balancer (I.D. hole was messed up...replace yours too. After - Market Brand / make worked fine for me.) Also a new Shear Pin, etc.

I did this 2 1/2 yrs ago in my own garage. And I'm not a car mechanic, but I know how to read & use tools. So don't get discouraged on this one. Give it a try! I think it ran us about $140.00 total to complete this repair. At 18,000 mi. later, it's still running fine.

MH / Rochester, NY
Crank bolt got loose and caused the harmonic balancer to sheer the roll pin that holds it to the sprocket. It also wore out the inside of the balancer. Replacing balancer and pin and re-torqueing bolt to spec.
Bolt that holds crankshaft pulley busted the threads off. What should I do to replace do I have to re thread it when I put another one in.
harmonic balancer bolt loosened --> $1200 repair --> occurred again 15,000 miles later with added complication of stripped crankshaft --> vehicle scrapped.
Pulley came off, wallowed out crankshaft. Drilled and tapped crank to a larger bolt size. Not sure about the shear pin,as I had to make new holes for it. I'm doing the repairs with everything intact.
something happened when I was driving cause the pulley to warp under normal driving conditions. Had to buy a new pulley and bolt/washer to fix.
After replacing the AC compressor and the three belts and then driving for a bit, the power steering went out on a left turn and the alternator light came in. After trying to put the alternator belt on once I saw the pulley was loose. I thought it was the rubber bonding at first. Now I have to find a way to get the broken roll pin out of the crank and get it replaced. I see the recall. I might as well see if I can get the bolt too. Good grief.
Heard a clinking sound under the hood, it appeared it had thrown a belt (no power streering, battery light on) I shut off the a/c and the sound went away. I assumed it was a bad tensioner that let the belt slip off. Drove it slowly a few miles to my mechanic and on inspection found the crank pin had sheared and the bolt had become loose. The balancer had obviously been spinning on the end of the crankshaft. In trying to remove the bolt the threads stripped and now I'm waiting to get his recomedation on a fix.
crank pulley bolt came lose, sheared the pin... got lucky and saved it before it broke the timing belt or the bolt.