First off, it is an automatic with overdrive. We bought it for parts but decided to get it running. When we got in there we found that the center of the flywheel was busted out all the way around. So we pulled tranny out and replaced it. The guy said that his daughter drove truck to a friends house and parked it, came out next morning and would not start. I think we still need to add or take away some shims, just got done last night. But it still starts alot of the times?????? Sometimes right up! I noticed when giving it gas, I can feel a type of vibration in the gas pedal, nothing outrageous or anything, but I do feel it and it stops when I let it off. I understand this could be carrier bearing, u-joint or what not. But could it be that the crankshaft is bent a little and it broke like that on that girl because she drove it a long distance without stopping and flywheel got hot and finally gave! What are the chances that the crankshaft is bent. Oh, I have drove it 20 miles there and back and another 15 there and back and it is driving all right. I know I should have took a ruler and spun the flywheel and watched it to make sure the distance did not change, but did not! If it was bent wouldn't the motor be screwed up driving it like that? It runs good!
Could crankshaft be bent on an 87 GMC S15?
It is possible that a crank will warp, or bend, but highly unlikely.
On an 87 the chances are the vibration you are feeling is one of two things, or a combination of both. That is, bad or hard motor mounts, or a bad harmonic balancer.
If you do have an %26quot;out of round%26quot; shaft, it would be at the front end and due to improper balancer installation. Watch the harmonic balancer as the engine idles and see if it has a wobble. If it does replace it. Then attack the motor mounts.
Were it my 87 truck, I would just drive on!
Could crankshaft be bent on an 87 GMC S15?
More than likely it's something else.If the crank was bent you would think it would shake badly as you increase the rpms Maybe you have the flywheels shims uneven ?
I would say that it was the problem to begin with. That's why it broke on his daughter.I would guess it's the torque converter being bent.
