On a 2003 Buick Century with a 3.1 how many hours would a mechanic shop take to replace a crank shaft? Another mechanic messed up and broke a bolt off in the harmonic balancer and then drilled it crooked. Mechanic shop wants to weld harmonic balancer and crank shaft together. Is this a better option?
Crankshaft weld 3.1 gm
- Thread starter Dehaka
- Start date
Sounds to me like the shop owes you a new crank and not a half assed repair.
GM Crankshaft & Harmonic Balancer Advice
2003 Buick Century 100 k original owner was my granny. So had a mechanic redo the oil pan and timing cover gaskets and throw on a new motor mount. (Also new brakes, oil, pump, thermostat, temp sensor, new harmonic balancer.) Upon pulling the harmonic balancer off he broke the bolt off inside...
bobistheoilguy.com
Yeah, I also thought this had already been discussed at length
The Balancer has to have force applied to hold the Crank Timing Gear......If not, The Gear can start wearing on the Woodruff key, A battle of whose harder!
You can't weld the balancer onto the crank very easily. Welding cast iron takes special knowledge.
Whoever said to do that is a dodo.
The shop owes you a proper repair but I wouldn't let them touch it again.
I have replaced cranks. Easiest and best way is to pull the engine and flip it over. Mark all the rods and mains so they don't get mixed up etc.
It's a lot of work and expensive labor wise. Likely more than the cars value.
Whoever said to do that is a dodo.
The shop owes you a proper repair but I wouldn't let them touch it again.
I have replaced cranks. Easiest and best way is to pull the engine and flip it over. Mark all the rods and mains so they don't get mixed up etc.
It's a lot of work and expensive labor wise. Likely more than the cars value.
It's probably best the shop put in a good used or remanufactured engine in it. When they do it, it might not be a bad idea if the OP pays for them to also put in a new set of OE engine mounts.
I wondered about this, too. A couple tacks will almost surely crack and laying enough heat into it to make it work will likely warp the crank or destroy whatever allows the balancer to, well, balance
Find a new mechanic/shop ASAP Blufeb95 is spot on.
I'll cast another vote against welding the HB to the crankshaft - what if you ever had to change the HB or the timing chain?
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Please do not let anyone even attempt this. I can assure you it's a bigger can of worms than you want to open. Aside from the obviously bad decision to put HEAT onto a crankshaft, I am a former Boilermaker welder, AWS Certified Welding Inspector (Google that if you wish), and Specification writer. I will try to explain this in layman's terms. The AWS has "prequalified" welding procedures that are acceptable to use without testing, for example, it is common knowledge that a 6011 or 7018 welding rod holds together A36 (mild steel). We don't need to test this, we know it works.
For base metals NOT listed in the Code (of which I can assure you, neither the crankshaft nor the material the Harmonic BALANCER are made of are)....When we are dealing with unknown materials, what is done to qualify a welding procedure is that you take a mock up of the materials you think will work (base metal samples from both materials) and weld them together with filler metal you think will work, then this test coupon is sent to a laboratory for tensile, chemical and ductility (destructive mechanical testing). Basically, the materials are pulled apart to failure in a hydraulic machine and the force required is measured. To pass for dissimilar materials, all that is needed is 60% of the weaker of the two materials, but you're NOT going to do this with peanut butter or the wrong filler metal (stick electrodes). The act of performing this testing is known as the procedure qualification record. This is, if you will, the recipe to follow to weld together the materials you wish to join. There are entire engineering books written on suggested base metal/filler metal combinations.
What I am telling you is that if some dodo brain is suggesting this insanity, you need a SPARE Harmonic Balancer and crankshaft and filler metal and weld them together, writing down and recording the essential variables (filler metal type, preheat, voltage, amperage, travel speed, etc.) then send it to a laboratory and pull them apart to prove the welding will hold. The sane thing to do is find another method of repair.
For base metals NOT listed in the Code (of which I can assure you, neither the crankshaft nor the material the Harmonic BALANCER are made of are)....When we are dealing with unknown materials, what is done to qualify a welding procedure is that you take a mock up of the materials you think will work (base metal samples from both materials) and weld them together with filler metal you think will work, then this test coupon is sent to a laboratory for tensile, chemical and ductility (destructive mechanical testing). Basically, the materials are pulled apart to failure in a hydraulic machine and the force required is measured. To pass for dissimilar materials, all that is needed is 60% of the weaker of the two materials, but you're NOT going to do this with peanut butter or the wrong filler metal (stick electrodes). The act of performing this testing is known as the procedure qualification record. This is, if you will, the recipe to follow to weld together the materials you wish to join. There are entire engineering books written on suggested base metal/filler metal combinations.
What I am telling you is that if some dodo brain is suggesting this insanity, you need a SPARE Harmonic Balancer and crankshaft and filler metal and weld them together, writing down and recording the essential variables (filler metal type, preheat, voltage, amperage, travel speed, etc.) then send it to a laboratory and pull them apart to prove the welding will hold. The sane thing to do is find another method of repair.
