Timing Belt Tensioner Pivot Bolt-snapped

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friedman
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Re: Timing Belt Tensioner Pivot Bolt-snapped

Post by friedman » Tue Sep 17, 2019 1:48 pm

I see enough of these busted that I save any I find when stripping a bad motor. I have never heard of anyone having a hard time removing the broken portion in the motor so you experience seems typical.
Carl in Virginia
75 spider
83 Bertone
njoconnor
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Re: Updated/completed: Timing Belt Tensioner Pivot Bolt-snapped

Post by njoconnor » Wed Sep 25, 2019 12:59 pm

First, thanks to all who contributed to this thread, especially Jim and Dave's comments on torque settings/meanings. I now have a metric fastener torque settings table in the garage, and it will be the go to, as opposed to misreading Mr. Haynes!

Second, while re-installing the water pump...yeah, 4th bolt snapped well below the manual's listed torque ( I was using a much lower torque from the fastener table). Pulled the other three, found 8.8 grade replacements at the local hardware, snugged them down. On examining the bolts, I saw this:

Note the thread stretching in the two long water pump bolts, and the incipient stretching in the broken tensionser bolt at the top. New rule: any bolt I have not previously removed/installed gets checked for stretching!

Finally, it all came together on Monday and Tuesday, fired on the second crank, and for some reason seems smoother/quieter at idle and there's some more kick on acceleration. I did not change the timing at all, but made sure everything was lined up on ) BTDC. Cooling system burped quickly, fan is working properly, no leaks! Only niggling issue is v-belt squeal on initial start up. I have a belt tension gauge (for v-belts) inbound; don't want to over tighten the v belt and risk the water pump/alternator bearings after all this.

Thanks again, everyone. Time for some Fall driving! (and golf).

Neil
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Neil O'Connor
Madison, WI
72 Fiat 124 Spider
14 Ram 1500 Ecodiesel
12 Jeep Grand Cherokee
71 Fiat 124 Coupe (long ago and far away...and very much missed!)
Various MOPAR's, Fords, VW's, Audis, and SAABs, and a Bimmer
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ST3Racer
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Re: Timing Belt Tensioner Pivot Bolt-snapped

Post by ST3Racer » Fri Sep 27, 2019 11:50 pm

There is tight, and then gorilla tight. Consult the torque tables. Most are based on the bolt/nut size.
Bill McMahan
Parker, Colorado
'69 124 Spider 2L ex EP racer, ex Volumex NASA ST3 Racecar - retired
'69 rebodied with '79 backdated chassis as '72 DP 1.8L Vintage Racer
'74 124 Abarth Stradale Replica
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friedman
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Re: Timing Belt Tensioner Pivot Bolt-snapped

Post by friedman » Sat Sep 28, 2019 10:08 am

The better running of your motor is probably because there was a slight change in ignition timing after everything was put back together. Who knows, maybe the exhaust cam was off a tooth previously and you got it set correctly when you did this job. In any event, good job and good results.
Carl in Virginia
75 spider
83 Bertone
njoconnor
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Re: Timing Belt Tensioner Pivot Bolt-snapped

Post by njoconnor » Wed Oct 02, 2019 5:20 pm

Thanks, Carl. Even my wife commented that she can't hear me coming down the street anymore unless I'm going uphill :) .

Now if the rain would let up, we can get some Fall driving in. Just might be able to run up to a favorite winery tomorrow to try a new release apple wine....

Neil
Neil O'Connor
Madison, WI
72 Fiat 124 Spider
14 Ram 1500 Ecodiesel
12 Jeep Grand Cherokee
71 Fiat 124 Coupe (long ago and far away...and very much missed!)
Various MOPAR's, Fords, VW's, Audis, and SAABs, and a Bimmer
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