Chrysler Repair/Removing Broken Center Crankshaft-harmonic balancer Bolt 1994 Plymouth Voyager SE 3.3L Gas Engine
QUESTION: Hi. For a long time now I've had a problem with the serpentine belt jumping off. When this first happened, I thought it was just an old belt that broke so I replaced it. The new belt jumped off at first rain. Installed another new belt and new tensioner & idler pulley. Belt popped off at first rain. Noticed power steering pulley shaft seemed wobbly. Replaced ps pump. Belt popped off within a few miles of driving. Removed ps unit and tried to realign the pulley thinking I didn't have it pressed in far enough. Belt popped off immediately. Guess I should have moved the pulley further out instead. Couldn't bear the thought of laying under that vehicle again (I'm claustrophobic) and so I shimmed the tensioner with a thick washer behind it. That made it better but belt came off again at next heavy rain. I had to get home so installed a new and slightly smaller belt. That worked and got me home and everywhere else for the next six months - rain or shine. Then researching this, I found out about the gates pulley shield and wanting to go back to the standard size belt I removed the washer-shim & installed the gates shield w/a new standard size belt. While doing this I noticed that the belt was really-really tight AND it seemed even tighter than the smaller belt that I had just removed, so I double-checked to make sure that I had been given the correct belt. I was, and when held against the smaller belt -it was slightly longer. So I shrugged off my concerns and started the vehicle. Immediately heard clanking & smelled rubber. Shut it down & checked everything. There were no obstructions and belt was installed according to diagram -exactly as I have installed it many times before. Checked tensioner and noticed it had no play at all. That belt was far too tight and I suspect that a broken motor-mount may have caused it. Is that poss? Also, by the way, after further research, I found out that the standard belt from O'reilly auto parts is nearly 1/2 inch longer than from all other sources (pepboys, advance, etc) that I checked. Wish I had purchased taht one... Anyhow, I then checked if all pulleys were tight and found the center crankshaft bolt had broken off. It was still there and at first I thought it was just loose but it came out in my hands... Now what do I do? LOL. I am going to remove the balancer and hopefully there is enough of the bolt left to get a pair of vice-grips on it, but if not, do you know what size drill bit and extractor I will need? And what to torque my new center bolt to? I'm now waiting on a manual a gates pulley conversion kit; and also thinking that I will prob. need to replace the balancer too. And I do realize that I should have done this right to begin with, however, the unfortunate situation that I'm in wouldn't allow that.
I've read a lot of your advice recently and I'm greatly impressed - so your advice & help here will be greatly appreciated. Thanks.
ANSWER: Hi John,
Unfortunately the shop manual doesn't give the bolt size except that it has a length of 5.9 inches, and it needs a thrust bearing and washer plate L-4524 if either of those have gone missing. The torque for the crankshaft bolt is 40 foot-pounds. So a dealer parts counter should show in the parts manual what the bolt diameter is.
You may need to rent a three arm puller to remove the pulley from the crankshaft. I don't see a balancer in the drawings but that may be an oversight. Thanks for the complete history. Sorry this has been so difficult.
You might do well if you haven't so far to take a straight edge and verify all the pulleys driven by the belt are in the same plane. Also, I presume the gates shield is a 'aplash shield' which fits between the tire/wheel and the pulley to circumvent rain water from being thrown on the belt/pulley.
Please read the PS below and respond to it.
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QUESTION: Hi Roland. I've called perhaps 5 dealerships and not a one can or would bother to give me the specs on this bolt (#6502976, replaces #6502278). But you gave me the length and so I know now that there's a good chance that when I remove the balancer - there will be some of it sticking out. And I don't want to remove the balancer until I have everything to do the job because although I've been told that my vehicle can stay were it is for as long as I need... my landlady is "an unbalanced bulldog" who becomes belligerent and threatening at the drop of a hat _ and I don't trust that she won't go back on what she said. yes, I know, time to move. I'm trying, lol.
-Actually it's a Dorman 82570 Tensioner Pulley Shield. Not a Gates. Sorry about that. And it's like a giant washer that you put on the outside of the tensioner and/or idler pulley that provides a "wall" to keep the belt on.
-I will buy a straight-edge.
-The Gates 38398K Conversion kit (that I just ordered, $97 on amazon) replaces the belt with one that is grooved on both sides and replaces the smooth idler and tensioner pulleys with grooved ones. This should eliminate the problem with the belt coming off, but it won't affect whatever is causing the belt to be so tight. I'm still thinking that a broken motor mount may have shifted the motor or do you think that a severely misaligned pulley could do that?
-I will also re-inspect to make sure all pulleys are moving free and not wobbly.
I can't see any relationship between the belt tension and a motor mount. Everything involved with the belt is attached to the motor proper and would be unaffected by a mount problem. I don't think you need to buy a straight edge to verify that all the pulleys are in the same plane and parallel to it, just any item with parallel sides and long enough to stretch across the faces of the various pulleys (something similar to a yard stick).
The 'splash shield' of which I speak is a panel that attaches to the inner side of the fender lining at its lower edge and intercepts splash-up from the roadway that would otherwise strike the crank pulley/belt and cause the belt to slip off. That item is removable and so could have fallen off or been left off in an earlier servicing. You noticed that the belt came off quickly in a rain as I recall, and that would be encouraged if that shield were absent.
Thanks for the rating and nomination which you can do again if you would like.