I read the archives about the recall on the crankshaft bolt, but it only listed certain years, excluding my (and many others') '90 Montero. Since this seems to be an issue on ALL 3.0's, shouldn't all 3.0's have been recalled, or at least give a discount on the $210 in parts, not to mention labor costs, due to a defective (and they'll tell you that's why the new bolt looks different (washer also)) part? Why do I have to suffer the bill for buying a '90 instead of a different year model?
What a crock... (probably because my mitsu dealer also sells GM) <img src="/forums/images/graemlins/shame.gif" alt="" />

I thought it was a $5 bolt and a 10 minute fix? Did yours break off?

I just had a old guy come over that I had given some parts to. He has a 3.0 that the bolt broke on the pulley. He went to the dodge dealer to get a new one. They wanted to sell him the old style bolt. The dealer said that was the only one made. I have been looking for the part number for the new style bolt for 30 minutes.
Does anybody have this or the recall info.
I won't even start on what I think about the search function.

Dan -

Try this from the archives:

TSBs

Frank

Not only was it just certain YEARS recalled, but only certain VIN #s during the years that were recalled. I took mine in, and when they ran the VIN, it came back saying I didn't need to replace the bolt. <img src="/forums/images/graemlins/rolleyes.gif" alt="" />

looks like MB138069
Phil whats the number!1???

So if my truck has that old style bolt on it, It should be replaced with that new style one? I would think my remanufactured engine would be safe from that problem, but who knows?

The recall says specifically to INSPECT the existing bolt and replace ONLY IF NECCESARY. The newer design was available long before the recall was ever launched- it was not a designed upgrade. What's more important is that the proper torque is applied to the bolt. I've recently had a 96 SR come in with a "newer style" bolt that had backed off damaging the crank gear and dampener. On top of that, the recall tightening procedure was done close to 2 years prior. Upon interviewing with the customer- we learned that the timing belt had been replaced within a few weeks of this existing failure. I'm convinced that the bolt was not tightened properly to the 135FT/lbs specifications resulting in the failure.



Joel, CA

Joel -

I've read the TSB many times, examined both bolts and aside from the increased machining on the old style bolt can find no possible reason for the problem other than the one given in the TSB and backed up by what you've stated. There have been many theories expressed, but none that seem correct to me other than improper torque application. But the problem could be compounded by bolt design.

The only other things that I would be suspicious about:

1) machining of the fat bolt to create the undercut for the threads might weaken the bolt at the transition line from threads to bearing surface

- but more likely -

2) the above plus over-torqueing where the fat part doesn't give any yield twist and sudden pressure is applied to the transition/bearing area as the threads elongate and weaken the transition area. With vibration over time, the break could occur.

However, both of those suppositions would result in break/shearing at/near the transition point and while some do break there what we often hear is that the bolt simply backs out. The bolt could break from a wrapped belt snatching a loose pulley against it - but here again, the remaining portion of many of the snapped bolts have been difficult to remove, indicating some elongation of the threads may have occurred.

So - perhaps there could be two separate problems with installation - over and under torque plus faulty design. It will likely always be a mystery.

Frank

I really gotta take some pix of the timing drive pulley-
on ALL of the 3l's I've taken apart, the timing pulley has SUNK onto the crank by at least a few thousandths.
Plenty to let the bolt loosen up!
Thus, I'd add 'timing pulley recession' to the list of possible causes for loosening.

fwiw,
t