1991 blazer vibration problem

[psx-dude]

my 91 blazer had a weird vibration problem, so i took it in to have it check out. this is after my transmission was replaced after i accidently slammed the transmission into park while going 5 mph. after replacing the motor mounts and checking the torque converter, my mechanic believes that the crankshaft is the problem.

my question is, how much would it cost to replace the crankshaft, or should i just get a new engine installed?

[RABarrett]

There are some tests that should be run before condemning this unit. Does the vibration go away with the vehicle rolling with the ignition off? Does the vibration appear without the vehicle stopped, but the engine operating at the same rpm? Are there guarantees that the tech is not guessing? If the crank is really the issue, a new engine will likely guarantee a repair. Considering the possibilities presenting with crankshaft issues, including pistons, rods, bearings,etc, the engine is likely the way to go. Ray

[Brokebyford]

If this happened after you had your transmission replaced it is a possibility that when they put the driveshaft back on they did not insert it the same way it was removed.To start off replacing the engine to try and cure a vibration will surely land you in the poor house.If you are even slightly mechanically inclined I would pull out the driveshaft and bring it in to have it checked and rebalanced.That will cost under $100 dollars and will not go to waste even if it's not the problem. While it's out replace the u joints which could very easily be damaged by the truck being thrown into park.

[psx-dude]

it is defiently the crankshaft because the engine shakes in nuetral and park. also the mechanic saw that the crankshaft was no round when he removed the transmission.

anyone know how much it will cost to get the 262 replaced in this vehicle at a dealer? (or even an upgrade to a 350)

[rstroud]

By just pulling the tranny, how did your mechanic see anything about the crank shaft?

[psx-dude]

well apparently by removing the plate between the transmission and the engine, you can see the crankshaft, and if it isn't round when the engine is running, then there is something wrong with it. i trust the mechanic.

now i'm just wondering how much it will cost at a dealer to get a crate motor installed.

[psx-dude]

hmm ok, well what is the largest engine i could put into my 1991 s-10 blazer?

[psx-dude]

one last thing, would this be a sufficient replacement engine that may last me up to another 200,000 miles? (yea, it's a big one, the original engine got up that much, so i expect a remanufacture to get up to as much)

http://www.sdpc2000.com/cart.asp?act...id=126&pid=92#

[tom3]

I believe this engine has the one piece rear main seal crankshaft setup and has no real crank extension from the rear of the engine. If the crank was bent it either would not run or would leak oil terribly. I suspect the thin stamped steel flywheel may be bent and the runout is causing your vibration. Just remove the cover behind the oil pan so you can see the flywheel and torque converter and see if the unit is shaking. The flywheel is not expensive but labor can be pretty steep to do the change. Slim possibility the balance weight that should be on the flywheel has come off, not likely though. The rebuilt engine would no doubt outlast the vehicle, if you decide to go that route.