Worth fixing a '97 Civic's crankshaft?


#1

Mechanic’s telling me the harmonic balancer and crankshaft needs to be replaced on my '97 Civic. Other than that, the car runs fine. What should I be looking to pay for this and is it even worth it?


#2

How many miles on the car? What are the symptoms that lead the mechanic to believe it needs a new harmonic balancer/crankshaft?


#3

Is the timing belt due for replacement?
If so, have you factored that additional cost into the equation?

If the car has an automatic transmission, when was the last time that the trans fluid was changed?

In other words, with a 17 year old car, there are other maintenance and/or repair issues that should be taken into consideration when deciding whether to spend the big bucks on a crankshaft replacement.


#4

Crankshaft replacement may as well be part of an engine overhaul. I can believe needing an harmonic balancer, but a crankshaft? I’d get a second opinion.


#5

I’d also get a second opinion. If the harmonic balancer is wobbling there are other ways to repair that without replacing the crankshaft.


#6

Balancers come apart and need replacing from time to time. If somehow the threads are shot on the crankshaft, or a bad crankshaft caused the balancer problem, its good bye car. No way would I put a new engine in it and no way would I have a new crank put on an old engine. So I agree on a second opinion but its sounds like you should be shopping for a different car. Just the balancer would be in the $500 range, then plus the timing belt, another 2-300, then if the engine, several thousand.


#7

I can buy the balancer being bad . . . seen it a few times

Not necessarily on a Honda

But I’m skeptical of the bad crank diagnosis

Here’s an idea . . . get a good used dirt cheap balancer from the junkyard. If all the wobbling is gone, then you didn’t need the crank after all


#8

@TEEJAY2; tell us why the mechanic thinks you need a new crankshaft. What are the tests that he performed and what were your reasons for going to the shop in the first place.

Yosemite


#9

The mechanic said that the threads going into the crankshaft is stripped. I think I see where this is headed…ughhh


#10

Depending on how bad the threads are stripped…it might just be a matter of “chasing” the threads on the crank. I would pursue every option before I replaced a crankshaft. I’ve not had this problem on a newer vehicle but the older cranks were mighty tough. In my opinion…I think your mechanic may just be looking for a boat payment. Get a second opinion from another mechanic.


#11

If that’s the case, I’d be inclined to hit it with an arc welder.


#12

Google “stripped crankshaft threads” if you haven’t already. Options include Helicoil (or other thread insert) and drill/rethread/larger bolt. See if you can find a mechanic who’s done one of these.


#13

If the threads are stripped, they can be chased with a tap, as a first try, to see how trashed the threads are. If the threads don’t clean up enough to hold the full torque required by the balancer, a drill-and-tap thread insert like a Heli-coil likely can be installed to repair the damage. You may also be able to tap the crank to the next size bolt of the correct length and grade (very important) Either way, is is much easier and cheaper than a new crank. If you mechanic doesn’t know what a Heli-coil is, find a new mechanic. These things have saved many a damaged thread for me in both steel and aluminum.


#14

Just out of curiosity . . . have any of you guys helicoiled a crankshaft snout?

I sure haven’t

Considering a crankshaft is hardened, I wonder how difficult it would be to drill out the threads and drop a helicoil in there . . .


#15

Honda crankshafts were - maybe still are - forged. I too wonder whether the threads could be chased, or tapped to a larger diameter, or if the crankshaft can be drilled out and helicoiled.


#16

Crankshafts are case hardened, not through hardened. Even a forged crank. You can drill a crank snout or a flywheel flange with a quality bit.


#17

@Bing; not a bad idea. with the age of the engine…why not.

Of course if it’s got a timing belt, I’d do that first…so there would be a rare instance that you’d need to access the front cover.

Yosemite