I'm attempting to do a timing belt service on a friend's '79.

Every fastener I've touched so far has been way over torqued - including the crank nose bolt....

So far I've tried a Proto 1/2" breaker bar with a 4' "cheater pipe." No go. This thing must be torqued to over 400#. I'm going to get a 3/4" breaker bar and an impact socket today, but if that doesn't work, I'm out of ideas. I'm working in my friend's garage, so air and a big impact are not available.

Any suggestions on how to remove an over torqued nose bolt without breaking things - or me.

James

 

First off the bolts may not have been over-torqued, but after sitting there for years without moving, the breakaway torque is much higher than the application torque.

Yes you do want a 3/4" socket and bar on the crank bolt, which has spec torque of almost 300Nm I think (from memory). I moved mine using the handle of a trolley jack slipped over the breaker bar (total length must have been more like 6'), and positioning where I could safely pull on the handle without risk to wings of car when it finally broke!

Another approach (worked well on inner track rods screwed into steering rack, and on the rear hub nut which is torqued higher than crank bolt) is to set up breaker bar resting on pad of trolley jack (you would need the car off the ground for this though).

Other people have had success with getting the starter motor to do the work, by setting up breaker bar wedged against floor so that when you flick the starter (ignition relay and fuel pump fuse removed) you are applying torque to undo the crank bolt. But others have warned against this approach so I'm not responsible!

Appreciate you don't have air, but the latest generation of cordless electric impact wrenches would be up to the job. Older corded wrenches could manage too, but you may need to pull rad to get enough clearance for an impact wrench.

But I'm sure a long enough handle and a 3/4" 27mm will do the trick.

 

Likely more "frozen" than "over-torqued" but that doesn't solve your problem. Bigger tools and periodic penetrating oil are what you've got to do. Tap with a hammer. Apply heat. Regular stuff.

 

Long reach 27mm 3/4 inch sq drive impact socket plus a long overturning moment lever minimum of 40 inches radius however you achieve it and then it will break torque.

1/2 inch sq drive socket system is just not adequate for this bolt.

Rgds

Fred

 

I broke my breaker bar on that bolt. I found success using (another) breaker bar lengthening it with a five foot section of exhaust pipe.

 

This is a very popular modification to 1/2" breaker bars, both for the crank nose bolt and the rear axle bolts. 1/2"-drive components are good for 150 lbs/ft or less, and pretty worthless by 250 lbs/ft. I was in denial on this for a long time, but after using 3/4"-drive pieces I'm a firm believer.

FredR states correctly that a deep impact socket is a good thing for this duty. I found that a Harbor Freight 3/4"-drive deep impact socket is exactly the right length to fit over the bolt and leave the outer end of the socket at the end of the belt pulleys, so no extensions needed on the socket. Stratford Shark correctly shares that the right breaker bar, perhaps with extensions to get out to four or five feet, is the second requirement.

In my decades-long tool collecting effort, I found a 3/4"-drive adapter that allows me to poke the end of a long demolition bar through. The bar is almost 5 feet long, and allows relatively effortless removal of the crank bolt. You can still feel some flex as you pull with a long lever, but the bolt will come out. With the car on the lift, "pulling" on the handle is done from underneath these days, so that there's no chance of damage to a fender if/when the bolt gives way.

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If you want to see something pretty amazing, use a piece of pipe cheater on your 1/2"-drive breaker bar, but move the pipe out a couple inches before you pull on it. The amount of bending at the end before the metal gives up is pretty impressive.

Also-- don't be tempted to use your 3/4-drive click-stop torque wrench as a breaker bar. Apply more than the max rated torque and you risk twisting the little cams inside, rendering the wrench useless as anything other than an expensive breaker bar in the future.

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Your local tool and equipment rental shop will have the breaker bar and socket available if you don't want to own one.

 

Starter trick will get it out.

Static friction on a high torque fastener can be a bear, but a "shock" load on it to losen it, is generally very effective.

 

I used a 5' pipe on a breaker bar and was unable to get mine loose.

The radiator (but not A/C condenser) was out - it wouldn't have fit otherwise, and it came loose after maybe 5 seconds of "rattling" with one of these:

https://www.milwaukeetool.com/power-...rdless/2763-22

I borrowed one. Maybe you can rent one. The thing is a beast.

 

I loosened my bolt with a 2' breaker bar and 4' pipe overlapping about 1' for a total lever of 5' and it still took about all I could muster to break it free.
Do it the easy way, get your car up on stands if not already, use the breaker bar only and rest the handle on your jack. Double check that the socket is firmly seated on the bolt head and slowly pump up the jack and it will loosen with hardly any effort from you. That bolt is nothing verses the weight of the car and a floor jack.

 

pull the radiator and get a portable air compressor, and an impact gun with deep 27 MM socket,
it will come right off,
no drama

 

I had similar results with a portable impact wrench. Expensive but well worth it. Took out the crank bolt with no sweat.
http://www.ingersollrandproducts.com...rque-impactool

 

A torque multiplier will do the trick. I'm sure they have them at harbour freight.

Like this one.

http://www.princessauto.com/en/detai...er/A-p8160665e

Or as others have said an impact wrench will also do the trick.

The torque multiplier is also great for the rear axle nuts and re-torquing them.

 

Wow! 1100 ft-lb on a 1/2" lithium-ion impact. Impressive!

 

So, it has been noted that 1/2 drive will not be adequate for many of these bolts. I use Harbor Freight 3/4" drive 27mm socket on their breaker or ratchet (although I feared damaging the ratchet mechanism but it has held up well) with the 4 foot handle from my floor jack slipped over it. That's more than enough for the standard 218 lb ft, but I have encountered some bolts that must have been over 800 lb ft as it required every ounce of leverage I could muster. It has always worked.

 

I did my rear axle nuts by loading the socket bar against the floor and rolling the car. Front crank bolt was loosened with a 30" bar with some effort. Imagine my surprise when I went to remove the seats from my Miata in order to fit a roll bar - difficult to get a long bar involved until I had around 30" of extensions so I could stand outside the car, and even then it was as close as I want to get to busting a gut! The front bolts werent too bad, but all 4 rear bolts were a real bear! We did two cars the same day and they both had the same issues.

jp 83 Euro S AT 56k