1G stubborn crankshaft sprocket bolt

[pdxkris]

I recently bought a 1990 Laser RS w/ ~150k miles on it, and since the last owner couldn't tell me when the timing belt was last replaced, I'm currently in the process of replacing a whole slew of parts (fuel filter, IM/EM/turbo/head gaskets, timing components, etc) just as preventative maintenance.

So far things have gone pretty well (thanks to all the great posts here, along with the hanyes, chiltons, and backup CD), but the crankshaft sprocket is really giving me a hard time.

I thought I was prepared to take it off, since I have a 1/2" drive, 25" breaker bar and the crank holder tool (bought off ebay), but here's the results of that attempt :

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I saw another post where somebody said to leave the car in gear, set the e-brake, and have somebody hold the brakes down while trying to crack the bolt loose, but that didn't work either (sprocket spun).

so, I broke down and bought an electric impact wrench at HF (1/2" Electric Impact Wrench), but the bolt didn't budge.

I've heard about the idea of using the car's starter, as well as blocking the flywheel, but I'm wondering if there are better, safer, alternatives out there I should try first?

I don't have an air compressor, so air-impact is out. I considered a cheap air compressor from HF and a air-impact gun, but I don't think the cheap (<$150) air compressors have the necessary oomph (please correct me if I'm wrong!).

Any suggestions greatly appreciated.

Thanks all

 

[romeen]

It's at my parent's house on a mountain in Newberg, OR at the moment (I think that's what you were after?)

Yes, if the car was close by I was going to offer to lend a hand but Newberg is a bit far for me.

 

[Shadow21]

If you have an engine hoist it may come in handy right here. I ran into this issue with my brothers buick and his crank bolt was absolutely stuck. We tried using a jack under the wrench to break it loose and all of that crap. Finally we rigged up the engine hoist to pull up on the wrench and broke it free.

 

[90moneypit]

Reading the specs on that one from Harbor Freight it states 240 ft/lbs and 2400 impact/minute max. That is more than enough to crack that bolt! You probably got a dud from HF (it happens) and need to take it back for replacement. They're normally pretty cool about it since the lower price = lower quality control by the mfg. I bought a lot of various one time/throw away tools plus engine stands, cherry pickers etc from them over the years (with no problems) but some of their 110v tools have died within hours! I can't recommend their grinders or drills for that reason, they'll replace it once with a smile but after that... they start getting less friendly about it if you know what I mean.

 

[ramsack]

impacts only work good if you have a compressor with a very big tank with LARGE diameter hose that isn't too long. if you're trying to use a wheel-around sears compressor and a 50-ft puny 1/2" hose, you're lucky if it can even undo lug nuts. spending the money on a proper air-tool system is a lot of money and money for that i would think would be better spent on special hand tools or fabrication equipment.

 

[gusu]

I had the same problem when I did mine.

 

[pdxkris]

impacts only work good if you have a compressor with a very big tank with LARGE diameter hose that isn't too long. if you're trying to use a wheel-around sears compressor and a 50-ft puny 1/2" hose, you're lucky if it can even undo lug nuts. spending the money on a proper air-tool system is a lot of money and money for that i would think would be better spent on special hand tools or fabrication equipment.

Funny you should mention this, I was actually just considering picking up this compressor and impact wrench:

2 HP, 4 Gallon, 115 PSI Twin Tank Air Compressor

1/2" Impact Wrench

Based on the PSI and CFM requirements on the wrench, and what the compressor says it puts out, it seems like it should be fine. Am I missing something? In my mind it seems like a big tank isn't necessary since I only need a couple second burst of air and don't plan on running the impact wrench for long periods of time.

After 20% coupons, I can pick them up for a total of $136, which is pretty appealing.

 

[ramsack]

trust me, that compressor is not good enough for an impact. those things are better for really tiny air nailers, and even with those tools they are turning on and off every minute. they are meant to fill tires and do small house repair jobs. impacts use A LOT of air, they require a lot of pressure and a lot of volume. a lot of volume of air needs to be available so the pressure doesn't just shoot down to nothing right away so the impact can actually hammer off the bolt.

 

[Shadow21]

hell i have the lowes 60 gallon compressor with the 220v motor and it just barely good enough to run good air tools.. Youll never power an impact wrench on that tiny compressor.

 

[pdxkris]

The starter method did the trick

It took 2 quick blips, and it came right off with no problems.

Thanks all!

 

[RamenPride]

I have a simple but effective method that I used the first time. Use the car jack... I used a 3 Ton jack. I simply place the breaker bar end into jack's cup and used it to turn/leverage the crank bolt. The jack WILL NOT give because it's on the most solid surface and it's hydraulically pushing the wrench and turning the bolt. Good Luck

I know the issue has been resolved, but just wanted to chime in anyway since I had the exact same problem yesterday. I have that same Harbor Freight electric impact wrench. When I changed out the front hubs a few years ago it spun the axle nut off in just a few seconds. I only mention this because I think the torque on those is around 120 ft/lbs maybe? Anyway, it did't budge the crank bolt at all, which is supposed to be torqued at around 90 ft./lbs so needless to say I was kind of confused. The car is basically in pieces w/no timing belt or battery, so I couldn't use the starter method. I used the above method, and jammed a screwdriver into the flywheel to keep it from turning. I thought it would break the bolt loose in seconds, but it ended up lifting the engine and eventually the front of the car off of the jackstands! I was using a cheap Harbor Freight impact socket and breaker bar, so I tried bouncing the car since it was in the air to see if that would work. I was waiting for the breaker bar and/or socket to snap at any time since I could see the bar bending, but they held (well, the socket eventually cracked a little). I ended up putting a pipe/handle of the floor jack over the breaker bar and positioned it so i could just jump on it and it eventually broke loose.

 

[ramsack]

yea you don't usually have to tighten the piss out of the axle nuts if they have a castle nut to hold them, which is probably why they were easy.